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Sample records for 316l ss specimens

  1. Structure/property (constitutive and dynamic strength/damage) characterization of additively manufactured 316L SS

    NASA Astrophysics Data System (ADS)

    Gray, G. T., III; Livescu, V.; Rigg, P. A.; Trujillo, C. P.; Cady, C. M.; Chen, S. R.; Carpenter, J. S.; Lienert, T. J.; Fensin, S.

    2015-09-01

    For additive manufacturing (AM), the certification and qualification paradigm needs to evolve as there exists no "ASTM-type" additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

  2. Resistance of superhydrophobic and oleophobic surfaces to varied temperature applications on 316L SS

    NASA Astrophysics Data System (ADS)

    Shams, Hamza; Basit, Kanza; Saleem, Sajid; Siddiqui, Bilal A.

    316L SS also called Marine Stainless Steel is an important material for structural and marine applications. When superhydrophobic and oleophobic coatings are applied on 316L SS it shows significant resistance to wear and corrosion. This paper aims to validate the coatings manufacturer's information on optimal temperature range and test the viability of coating against multiple oil based cleaning agents. 316L SS was coated with multiple superhydrophic and oleohobic coatings and observed under SEM for validity of adhesion and thickness and then scanned under FFM to validate the tribological information. The samples were then dipped into multiple cleaning agents maintained at the range of operating temperatures specified by the manufacturer. Coating was observed for deterioration over a fixed time intervals through SEM and FFM. A comparison was drawn to validate the most critical cleaning agent and the most critical temperature at which the coating fails to leave the base substrate exposed to the environment.

  3. Structure and Long-Term Stability of Alkylphosphonic Acid Monolayers on SS316L Stainless Steel.

    PubMed

    Kosian, Medea; Smulders, Maarten M J; Zuilhof, Han

    2016-02-01

    Surface modification of stainless steel (SS316L) to improve surface properties or durability is an important avenue of research, as SS316L is widely used in industry and science. We studied, therefore, the formation and stability of a series of organic monolayers on SS316L under industrially relevant conditions. These included acidic (pH 3), basic (pH 11), neutral (Milli-Q water), and physiological conditions [10 mM phosphate-buffered saline (PBS)], as well as dry heating (120 °C). SS316L was modified with alkylphosphonic acids of chain length (CH2)n with n varying between 3 and 18. While alkylphosphonic acids of all chain lengths formed self-assembled monolayers with hydrophobic properties, only monolayers of chain lengths 12-18 formed ordered monolayers, as evidenced by static water contact angle (SCA), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and infrared reflection absorption spectroscopy (IRRAS). A long-term stability study revealed the excellent stability of monolayers with chain lengths 12-18 for up to 30 days in acid, neutral, and physiological solutions, and for up to 7 days under dry heating. Under strong basic conditions a partial breakdown of the monolayer was observed, especially for the shorter chain lengths. Finally, the effect of multivalent surface attachment on monolayer stability was explored by means of a series of divalent bisphosphonic acids. PMID:26771302

  4. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures.

    PubMed

    Lee, Jason S; Ray, Richard I; Lowe, Kristine L; Jones-Meehan, Joanne; Little, Brenda J

    2003-04-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures. PMID:14618716

  5. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

    NASA Technical Reports Server (NTRS)

    Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

    2003-01-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

  6. Corrosion-erosion test of SS316L grain boundary engineering material (GBEM) in lead bismuth flowing loop

    NASA Astrophysics Data System (ADS)

    Saito, Shigeru; Kikuchi, Kenji; Hamaguchi, Dai; Tezuka, Masao; Miyagi, Masanori; Kokawa, Hiroyuki; Watanabe, Seiichi

    2012-12-01

    To evaluate the lifetime of structural materials utilized in a spallation neutron source, corrosion tests in lead-bismuth eutectic (LBE) have been done at JAEA. Austenitic steels are preferable as the structural material for ADS. However, previous studies have revealed that austenitic steel SS316 shows severe corrosion-erosion in LBE because of LBE penetration through grain boundaries and separation of grains. So it was considered that GBE (grain-boundary engineered) materials may be effective to improve the corrosion resistance of austenitic steels in LBE. In this study, the results of corrosion tests on austenitic steel SS316L-BM (base metal) and SS316L-GBEM (grain-boundary-engineered material) under flowing LBE conditions will be reported. The corrosion test was performed using the JAEA lead-bismuth material corrosion loop (JLBL-1). The experimental conditions were as follows: The high and low temperature parts of the loop were 450 °C and 350 °C, respectively. The flow velocity at the test specimens was about 0.7 m/s. The oxygen concentration in LBE was not controlled and was estimated to have been very low. After the 3600 h of operation, macroscopic, SEM, and SIM observations and EDX analysis were carried out. The results showed that the corrosion depth and LBE penetration through the grain boundaries of the 316SS-GBEM were smaller than those of the 316SS-BM.

  7. Electrochemical and in vitro bioactivity of polypyrrole/ceramic nanocomposite coatings on 316L SS bio-implants.

    PubMed

    Madhan Kumar, A; Nagarajan, S; Ramakrishna, Suresh; Sudhagar, P; Kang, Yong Soo; Kim, Hyongbum; Gasem, Zuhair M; Rajendran, N

    2014-10-01

    The present investigation describes the versatile fabrication and characterization of a novel composite coating that consists of polypyrrole (PPy) and Nb2O5 nanoparticles. Integration of the two materials is achieved by electrochemical deposition on 316L stainless steel (SS) from an aqueous solution of oxalic acid containing pyrrole and Nb2O5 nanoparticles. Fourier transform infrared spectral (FTIR) and X-ray diffraction (XRD) studies revealed that the existence of Nb2O5 nanoparticles in PPy matrix with hexagonal structure. Surface morphological analysis showed that the presence of Nb2O5 nanoparticles strongly influenced the surface nature of the nanocomposite coated 316L SS. Micro hardness results revealed the enhanced mechanical properties of PPy nanocomposite coated 316L SS due to the addition of Nb2O5 nanoparticles. The electrochemical studies were carried out using cyclic polarization and electrochemical impedance spectroscopy (EIS) measurements. In order to evaluate the biocompatibility, contact angle measurements and in vitro characterization were performed in simulated body fluid (SBF) and on MG63 osteoblast cells. The results showed that the nanocomposite coatings exhibit superior biocompatibility and enhanced corrosion protection performance over 316L SS than pure PPy coatings. PMID:25175190

  8. Effects of Heat Treatments on Microstructure Changes in The Interface of Cu/SS316L Joint Materials

    SciTech Connect

    Xu, Q.; Yoshiie, T.; Edwards, Danny J.

    2000-09-01

    In both joints iron and chromium diffused from the stainless steel into the copper alloy, producing a narrow zone of about a 15 ?m containing FeCr precipitates and small voids. Failure in some bending tests occurred by a crack propagating through this zone in a direction parallel to the interface, indicating that the formation of these precipitates may not be conducive to good joint properties. The results of annealing experiments showed that temperatures # 673 K did not change the initial microstructure or composition of CuAl25/SS316L and CuNiBe/SS316L joints. Although there are no data from annealing experiments longer than 100 hours, it is expected that the microstructure and composition of CuAl25/SS316L and CuNiBe/SS316L are stable under the thermal operating conditions of fusion reactors. However, irradiation may lead to significant changes because of radiation-enhanced segregation, precipitation or dissolution near and at the interface that could alter the properties. In addition, the preexisting voids near the interface of the joints may coarsen under irradiation and enhance the sensitivity of joints to failure. Given the uncertainties in the response to irradiation, neutron irradiation experiments should be performed at appropriate temperatures to investigate the response of the different materials.

  9. A novel silica nanotube reinforced ionic incorporated hydroxyapatite composite coating on polypyrrole coated 316L SS for implant application.

    PubMed

    Prem Ananth, K; Joseph Nathanael, A; Jose, Sujin P; Oh, Tae Hwan; Mangalaraj, D

    2016-02-01

    An attempt has been made to deposit a novel smart ion (Sr, Zn, Mg) substituted hydroxyapatite (I-HAp) and silica nanotube (SiNTs) composite coatings on polypyrrole (PPy) coated surgical grade 316L stainless steel (316L SS) to improve its biocompatibility and corrosion resistance. The I-HAp/SiNTS/PPy bilayer coating on 316L SS was prepared by electrophoretic deposition technique. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies were carried out. These results confirmed the significant improvement of the corrosion resistance of the 316L SS alloy by the I-HAp/SiNTs/PPy bilayer composite coating. The adhesion strength and hardness test confirmed the anticipated mechanical properties of the composite. A low contact angle value revealed the hydrophilic nature. Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used for the leach out analysis of the samples. Added to this, the bioactivity of the composite was analyzed by observing the apatite formation in the SBF solution for 7, 14, 21 and 28days of incubation. An enhancement of in vitro osteoblast attachment and cell viability was observed, which could lead to the optimistic orthopedic and dental applications. PMID:26652470

  10. Morphological and Mechanical Properties of Hydroxyapatite Bilayer Coatings Deposited on 316L SS by Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Sidane, Djahida; Khireddine, Hafit; Yala, Sabeha; Ziani, Salima; Bir, Fatima; Chicot, Didier

    2015-10-01

    The present paper reports on the influence of the addition of TiO2 and SiO2 oxides as sub-layer, on the morphological and mechanical properties of the hydroxyapatite (HAP) bioceramic coatings deposited on 316L stainless steel by sol-gel method in order to improve the properties of hydroxyapatite and expand its clinical application. The stability of the sols suspensions was evaluated by measuring the time dependence of the viscosity. Annealed properties of the coatings were analyzed by XPS, XRD, SEM, and EDS. The Vickers microhardness of the coatings is obtained under the same indentation load of 10 g. The hydroxyapatite coating deposited on the surface of the 316L SS substrate exhibits a porous carbonated apatitic structure. The results clearly demonstrate that HAP-TiO2 and HAP-SiO2 bilayer coatings where hydroxyapatite is deposited on the surface of TiO2- and SiO2-coated 316L SS substrate systems were highly homogeneous and uniform and show higher microhardness compared to HAP-coated 316L SS. A gap of nearly 10 pct is observed. The addition of TiO2 and SiO2 as sub-layer of a hydroxyapatite coating results in changes in surface morphology as well as an increase of the microhardness.

  11. Computaional Modeling of the Stability of Crevice Corrosion of Wetted SS316L

    SciTech Connect

    F. Cui; F.J. Presuel-Moreno; R.G. Kelly

    2006-04-17

    The stability of localized corrosion sites on SS 316L exposed to atmospheric conditions was studied computationally. The localized corrosion system was decoupled computationally by considering the wetted cathode and the crevice anode separately and linking them via a constant potential boundary condition at the mouth of the crevice. The potential of interest for stability was the repassivation potential. The limitations on the ability of the cathode that are inherent due to the restricted geometry were assessed in terms of the dependence on physical and electrochemical parameters. Physical parameters studied include temperature, electrolyte layer thickness, solution conductivity, and the size of the cathode, as well as the crevice gap for the anode. The current demand of the crevice was determined considering a constant crevice solution composition that simulates the critical crevice solution as described in the literature. An analysis of variance showed that the solution conductivity and the length of the cathode were the most important parameters in determining the total cathodic current capacity of the external surface. A semi-analytical equation was derived for the total current from a restricted geometry held at a constant potential at one end. The equation was able to reproduce all the model computation results both for the wetted external cathode and the crevice and give good explanation on the effects of physicochemical and kinetic parameters.

  12. COMPUTATIONAL MODELING OF CATHODIC LIMITATIONS ON LOCALIZED CORROSION OF WETTED SS 316L, AT ROOM TEMPERATURE

    SciTech Connect

    F. Cui; F.J. Presuel-Moreno; R.G. Kelly

    2005-10-13

    The ability of a SS316L surface wetted with a thin electrolyte layer to serve as an effective cathode for an active localized corrosion site was studied computationally. The dependence of the total net cathodic current, I{sub net}, supplied at the repassivation potential E{sub rp} (of the anodic crevice) on relevant physical parameters including water layer thickness (WL), chloride concentration ([Cl{sup -}]) and length of cathode (Lc) were investigated using a three-level, full factorial design. The effects of kinetic parameters including the exchange current density (i{sub o,c}) and Tafel slope ({beta}{sub c}) of oxygen reduction, the anodic passive current density (i{sub p}) (on the cathodic surface), and E{sub rp} were studied as well using three-level full factorial designs of [Cl{sup -}] and Lc with a fixed WL of 25 {micro}m. The study found that all the three parameters WL, [Cl{sup -}] and Lc as well as the interactions of Lc x WL and Lc x [Cl{sup -}] had significant impact on I{sub net}. A five-factor regression equation was obtained which fits the computation results reasonably well, but demonstrated that interactions are more complicated than can be explained with a simple linear model. Significant effects on I{sub net} were found upon varying either i{sub o,c}, {beta}{sub c}, or E{sub rp}, whereas i{sub p} in the studied range was found to have little impact. It was observed that I{sub net} asymptotically approached maximum values (I{sub max}) when Lc increased to critical minimum values. I{sub max} can be used to determine the stability of coupled localized corrosion and the critical Lc provides important information for experimental design and corrosion protection.

  13. Reduction of 3T3 Fibroblast Adhesion on SS316L by Methyl-Terminated SAMs

    PubMed Central

    Raman, Aparna; Gawalt, Ellen S.

    2010-01-01

    Inhibiting the non-specific adhesion of cells and proteins to biomaterials such as stents, catheters and guide wires is an important interfacial issue that needs to be addressed in order to reduce surface-related implant complications. Medical grade stainless steel 316L was used as a model system to address this issue. To alter the interfacial property of the implant, self assembled monolayers of long chain phosphonic acids with −CH3, −COOH, −OH tail groups were formed on the native oxide surface of medical grade stainless steel 316L. The effect of varying the tail groups on 3T3 fibroblast adhesion was investigated. The methyl terminated phosphonic acid significantly prevented cell adhesion however presentation of hydrophilic tail groups at the interface did not significantly reduce cell adhesion when compared to the control stainless steel 316L. PMID:21461313

  14. Effect of Different Degrees of Sensitization on the EIS Response of 316L and 316 SS in Transpassive Region

    NASA Astrophysics Data System (ADS)

    Morshed Behbahani, K.; Pakshir, M.

    2014-06-01

    Different heat treatments were conducted on 316L and 316 stainless steels, and the sensitized specimens were characterized using anodic polarization and EIS tests in 0.5 M H2SO4 containing 0.01 molar KSCN. The potential ranges related to the transpassive region related to each specimen were determined. The EIS experiments were conducted at different potentials in that region, and the results showed the presence of three different regions, namely the anodic dissolution of the passive layer, dissolution of the grain boundaries, and the occurrence of pitting corrosion owing to the variations in the anodic potential. The higher the applied sensitization temperature, the lower the obtained charge-transfer resistance ( R ct) values, but healing effect was observed at the temperatures above 600 °C for these alloys.

  15. Thermally Driven Stability of Octadecylphosphonic Acid Thin Films Grown on SS316L

    PubMed Central

    Lim, Min Soo; Smiley, Katelyn J.; Gawalt, Ellen S.

    2010-01-01

    Stainless steel 316L is widely used as a biomedical implant material; however, there is concern about the corrosion of metallic implants in the physiological environment. The corrosion process can cause mechanical failure due to resulting cracks and cavities in the implant. Alkyl phosphonic acid forms a thin film by self-assembly on the stainless steel surface and this report conclusively shows that thermal treatment of the octadecylphosphonic acid (ODPA) film greatly enhances the stability of the ODPA molecules on the substrate surface. AFM images taken from the modified substrates revealed that thermally treated films remain intact after methanol, THF and water flushes while untreated films suffer substantial loss. Water contact angles also show that the hydrophobicity of thermally treated films does not diminish after being incubated in a dynamic flow of water for a three hour period while the untreated film becomes increasingly hydrophilic due to loss of ODPA. IR spectra taken of both treated and untreated films after water and THF flushes show that the remaining film retains its initial crystallinity. A model is suggested to explain the stability of ODPA film enhanced by thermal treatment. An ODPA molecule is physisorbed to the surface weakly by hydrogen bonding. Heating drives away water molecules leading to the formation of strong monodentate or mixed mono/bi-dentate bonds of ODPA molecule to the surface. PMID:20648546

  16. Thermally driven stability of octadecylphosphonic acid thin films grown on SS316L.

    PubMed

    Lim, Min Soo; Smiley, Katelyn J; Gawalt, Ellen S

    2010-01-01

    Stainless steel 316L is widely used as a biomedical implant material; however, there is concern about the corrosion of metallic implants in the physiological environment. The corrosion process can cause mechanical failure due to resulting cracks and cavities in the implant. Alkyl phosphonic acid forms a thin film by self-assembly on the stainless steel surface and this report conclusively shows that thermal treatment of the octadecylphosphonic acid (ODPA) film greatly enhances the stability of the ODPA molecules on the substrate surface. AFM images taken from the modified substrates revealed that thermally treated films remain intact after methanol, THF, and water flushes, whereas untreated films suffer substantial loss. Water contact angles also show that the hydrophobicity of thermally treated films does not diminish after being incubated in a dynamic flow of water for a 3-hour period, whereas the untreated film becomes increasingly hydrophilic due to loss of ODPA. IR spectra taken of both treated and untreated films after water and THF flushes show that the remaining film retains its initial crystallinity. A model is suggested to explain the stability of ODPA film enhanced by thermal treatment. An ODPA molecule is physisorbed to the surface weakly by hydrogen bonding. Heating drives away water molecules leading to the formation of strong monodentate or mixed mono/bi-dentate bonds of ODPA molecule to the surface. PMID:20648546

  17. Development of Silica Glass Coatings on 316L SS and Evaluation of its Corrosion Resistance Behavior in Ringer's Solution

    NASA Astrophysics Data System (ADS)

    Vijayalakshmi, U.; Rajeswari, S.

    2012-12-01

    Sol-gel derived silica glasses have many promising features, including low-temperature preparation as well as chemical and physical stability. Two silica glasses with Si100 and Si80 composition were prepared to understand the factors contributing to the rate of bioactivity. The effects of pH, solution aging temperature, and molar ratio of H2O/tetraethyl orthosilicate (TEOS) were studied, and the obtained powder sample was characterized by Fourier transform infrared spectroscopy, X-ray diffraction studies, and scanning electron microscopy. The synthesized silica glasses were deposited on 316L SS by the spin coating method at the optimized speed of 2000 revolutions per minute. The corrosion resistance behavior of the coatings was determined by (1) open-circuit potential vs time of exposure, (2) electrochemical impedance spectroscopy, and (3) cyclic polarization in Ringer's solution. A higher breakdown potential ( E b) and repassivation potential ( E p) value with lower current density was obtained from cyclic polarization. Similar results were observed from impedance analysis with higher charge transfer resistance ( R ct) and lower double layer capacitance ( C dl) indicating the corrosion resistance behavior of the coatings compared with the uncoated 316L stainless steel. From the results, it was observed that both Si100 and Si80 glass coatings had a positive effect on the corrosion resistance behavior. An adhesive strength of 46 MPa and 45 MPa was obtained for the Si100 and Si80 coatings, respectively. An accelerated leach out study was carried out by impressing the potential at their breakdown potential to determine the effect of glass coating for long-term contact between the implant and a normal biological medium.

  18. Low-Temperature Aging of Delta-Ferrite in 316L SS Welds; Changes in Mechanical Properties and Etching Properties

    NASA Astrophysics Data System (ADS)

    Abe, Hiroshi; Shimizu, Keita; Watanabe, Yutaka

    Thermal aging embrittlement of LWR components made of stainless cast (e.g. CF-8 and CF-8M) is a potential degradation issue, and careful attention has been paid on it. Although welds of austenitic stainless steels (SSs) have γ-δ duplex microstructure, which is similar to that of the stainless cast, examination on thermal aging characteristics of the SS welds is very limited. In order to evaluate thermal aging behavior of weld metal of austenitic stainless steel, the 316L SS weld metal has been prepared and changes in mechanical properties and in etching properties at isothermal aging at 335°C have been investigated. The hardness of the ferrite phase has increased with aging, while the hardness of austenite phase has stayed same. It has been suggested that spinodal decomposition has occurred in δ-ferrite by the 335°C aging. The etching rates of δ-ferrite at immersion test in 5wt% hydrochloric acid solution have been also investigated using an AFM technique. The etching rate of ferrite phase has decreased consistently with the increase in hardness of ferrite phase. It has been thought that this characteristic is also caused by spinodal decomposition of ferrite into chromium-rich (α') and iron-rich (α).

  19. COMPUTATION MODELING OF LOCALIZED CORROSION STABILITY ON WETTED SS316L AT 25 AND 95 DEGREE C

    SciTech Connect

    F. Cuti; F.J. Presuel-Moreno; R.G. Kelly

    2005-10-13

    For corrosion resistant materials exposed to low-temperature atmospheric environments, the corrosion mode of highest risk is expected to be localized corrosion (pitting, crevice, stress-corrosion cracking) due to accumulation of aggressive species within thin solution layers and/or formation of occluded local geometries. The stability of such a localized corrosion site requires that the corroding site (anode) must dissolve at a sufficient high rate to maintain the critical chemistry, and a robust cathodic area (cathode) must exist that can provide sufficient cathodic current. The characteristics of both the anode and the cathode depend on a large number of physiochemical variables (e.g., temperature, ionic concentration, water layer thickness, etc) and electrochemical parameters (i.e., cathodic and anodic polarization behavior). The effects of all these parameters add significantly to the dimensionality of the problem and a systematic study of these parameters is thus more tractable computationally than experimentally. The objective of this study was to computationally characterize the stability of such a local corrosion site and explore the effects of physiochemical and electrochemical parameters on that stability. The overall goal is to contribute to the establishment of a scientific basis for the prediction of the stabilization of localized attack on wetted, corrosion resistant material surface. A localized corrosion site, illustrated in Figure 1, consists of two parts: (a) the external wetted surface (cathode) and (b) the crevice (anode). This study computationally separated the two and modeled them individually, linking them through the imposition of a common fixed potential at the junction point (i.e., the mouth of the crevice). An objected-oriented computational code, CREVICER, developed at UVa, was extended to study separately both the wet surface (cathode) and the crevice (anode). SS316L was chosen as the material of interest.

  20. Corrosion protection performance of porous strontium hydroxyapatite coating on polypyrrole coated 316L stainless steel.

    PubMed

    Gopi, D; Ramya, S; Rajeswari, D; Kavitha, L

    2013-07-01

    Polypyrrole/strontium hydroxyapatite bilayer coatings were achieved on 316L stainless steel (316L SS) by the electropolymerisation of pyrrole from sodium salicylate solution followed by the electrodeposition of porous strontium hydroxyapatite. The formation and the morphology of the bilayer coatings were characterised by Fourier transform infrared spectroscopy (FT-IR) and high resolution scanning electron microscopy (HRSEM), respectively. The corrosion resistance of the coated 316L SS specimens was investigated in Ringer's solution by electrochemical techniques and the results were substantiated with inductively coupled plasma atomic emission spectrometry (ICP-AES). The passive film underneath the polypyrrole layer is effective in protecting 316L SS against corrosion in Ringer's solution. Moreover, we believe that the top porous strontium hydroxyapatite layer can provide potential bioactivity to the 316L SS. PMID:23475060

  1. Effects of Hydrogen Gas Environment on Fatigue Strength at 107 cycles in Plain Specimen of Type 316L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Kawamoto, Kyohei; Ochi, Kazuhiko; Oda, Yasuji; Noguchi, Hiroshi

    In order to clarify the hydrogen effect on the fatigue strength at 107 cycles in a plain specimen of type 316L austenitic stainless steel, rotating bending fatigue tests in laboratory air and plane bending fatigue tests in 1.0 MPa dry hydrogen gas and in air at 313 K were carried out. The main results obtained are as follows. The observed fatigue behavior showed that the fatigue strength at 107 cycles in both environments is determined by the non-propagation of a fatigue crack of the order of the grain size. Also, the strength at 107 cycles in hydrogen gas is slightly higher than that in air. In the region of high-cycle fatigue, the fatigue life in hydrogen gas is longer than that in air, which is mainly caused by the longer crack initiation life in hydrogen gas. The crack propagation life in hydrogen gas is shorter than that in air but has only a small ratio to the fatigue life in this region.

  2. Effects of passive films on corrosion resistance of uncoated SS316L bipolar plates for proton exchange membrane fuel cell application

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Ning, Xiaohui; Tang, Hongsheng; Guo, Liejin; Liu, Hongtan

    2014-11-01

    The effects of passive films on the corrosion behaviors of uncoated SS316L in anode and cathode environments of proton exchange membrane fuel cells (PEMFCs) are studied. Potentiodynamic and potentiostatic polarizations are employed to study the corrosion behavior; Mott-Schottky measurements are used to characterize the semiconductor properties of passive films; X-ray photoelectron spectroscopy (XPS) analyses are used to identify the compositions and the depth profiles of passive films. The passive films formed in the PEMFC anode and cathode environments under corresponding conditions both behave as n-type semiconductor. The passive film formed in the anode environment has a single-layer structure, Cr is the major element (Cr/Fe atomic ratio > 1), and the Cr/Fe atomic ratio decreases from the surface to the bulk; while the passive film formed in the PEMFC cathode environment has a bi-layer structure, Fe is the major element (Cr/Fe atomic ratio < 0.5), and in the external layer of the bi-layer structure Fe content increases rapidly and gradually in the internal layer. SS316L shows better corrosion resistance owing to both the high content of Cr oxide in the passive film and low band bending in normal PEMFC anode environments.

  3. Improvement in the Corrosion Resistance of Austenitic Stainless Steel 316L by Ion Implantation

    NASA Astrophysics Data System (ADS)

    Cai, Xun; Feng, Kai

    In the present work, austenitic stainless steel 316L (SS316L) samples were implanted with Ni and Ni-Cr. A nickel-rich layer about 100 nm in thickness and a Ni-Cr enriched layer about 60 nm thick are formed on the surface of SS316L. The effects of ion implantation on the corrosion performance of SS316L are investigated in a 0.5 M H2SO4 with 2 ppm HF solution at 80°C by open circuit potential (OCP), potentiodynamic and potentiostatic tests. The samples after the potentiostatic test are analyzed by XPS. The results indicate that the composition of the passive film change from a mixture of Fe oxides and Cr oxide to a Cr oxide dominated passive film after the potentiostatic test. The solutions after the potentiostatic test are analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results reveal that Fe is selectively dissolved in all cases and a proper Ni and Ni-Cr implant fluence can greatly improve the corrosion resistance of SS316L in the simulated polymer electrolyte membrane fuel cells (PEMFCS) environment. They are in agreement with the electrochemical test results that the bare SS316L has the highest dissolution rate in both cathode and anode environments and the Ni and Ni-Cr implantation reduce markedly the dissolution rate. After the potentiostatic test the interfacial contact resistance (ICR) values are also measured. Ni and Ni-Cr are enriched in the passive film formed in the simulated PEMFC cathode environment after ion implantation thereby providing better conductivity than that formed in the anode one. A significant improvement of ICR is achieved for the SS316L implanted with Ni and Ni-Cr as compared to the bare SS316L, which is attributed to the reduction in passive layer thickness caused by Ni and Ni-Cr implantation. The ICR values for implanted specimens increase with increasing dose.

  4. Controlled electrophoretic deposition of HAp/β-TCP composite coatings on piranha treated 316L SS for enhanced mechanical and biological properties

    NASA Astrophysics Data System (ADS)

    Prem Ananth, K.; Nathanael, A. Joseph; Jose, Sujin P.; Oh, Tae Hwan; Mangalaraj, D.; Ballamurugan, A. M.

    2015-10-01

    Hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) bioactive materials have been used as individual coatings on steel implants employed in the fields of orthopedics and dentistry due to their excellent properties, which foster effective healing of the repair site. However, slow dissolution of HAp and fairly little fast dissolution of β-TCP present a major obstacle for such applications and this leads to the focus on the investigation of a mixture of HAp and β-TCP composite that forms biphasic calcium phosphate (BCP). The BCP coatings were achieved by thickness controlled electrophoretic deposition on piranha treated 316L SS. This method is well controlled and the anticipated dissolution rate could be attained with faster formation of new bone at the implant site, when compared to the individual HAp or β-TCP coating. The structural, functional, morphological and elemental composition of the coatings were characterized by using various analytical techniques. The BCP coating has been shown to have a role in obstructing the corrosion to a greater extent when in contact with SBF solution. The BCP coating also shows excellent in vitro and mechanical properties and osteoblasts cellular tests revealed that the coating was more effective in improving biocompatibility. This makes it an ideal candidate material for hard tissue replacement.

  5. Degradation of SS316L bipolar plates in simulated fuel cell environment: Corrosion rate, barrier film formation kinetics and contact resistance

    NASA Astrophysics Data System (ADS)

    Papadias, Dionissios D.; Ahluwalia, Rajesh K.; Thomson, Jeffery K.; Meyer, Harry M.; Brady, Michael P.; Wang, Heli; Turner, John A.; Mukundan, Rangachary; Borup, Rod

    2015-01-01

    A potentiostatic polarization method is used to evaluate the corrosion behavior of SS316L in simulated anode and cathode environments of polymer electrolyte fuel cells. A passive barrier oxide film is observed to form and reach steady state within ∼10 h of polarization, after which time the total ion release rates are low and nearly constant at ∼0.4 μg cm-2 h-1 for all potentials investigated. The equilibrium film thickness, however, is a function of the applied potential. The main ionic species dissolved in the liquid are predominately Fe followed by Ni, that account for >90% of the steady-state corrosion current. The dissolution rate of Cr is low but increases systematically at potentials higher than 0.8 V. The experimental ion release rates can be correlated with a point defect model using a single set of parameters over a broad range of potentials (0.2-1 V) on the cathode side. The interfacial contact resistance measured after 48 h of polarization is observed to increase with increase in applied potential and can be empirically correlated with applied load and oxide film thickness. The oxide film is substantially thicker at 1.5 V possibly because of alteration in film composition to Fe-rich as indicated by XPS data.

  6. Correlation between optical characterization of the plasma in reactive magnetron sputtering deposition of Zr N on SS 316L and surface and mechanical properties of the deposited films

    NASA Astrophysics Data System (ADS)

    Fragiel, A.; Machorro, R.; Muñoz-Saldaña, J.; Salinas, J.; Cota, L.

    2008-05-01

    Optical and surface spectroscopies as well as nanoindentation techniques have been used to study ZrN coatings on 316L stainless steel obtained by DC-reactive magnetron sputtering. The deposit process was carried out using initial and working pressures of 10 -6 Torr and 10 -3 Torr, respectively. The experimental set-up for optical spectra acquisition was designed for the study in situ of the plasma in the deposition chamber. Auger spectroscopy, SEM and X-ray diffraction were used to characterize the coatings. Nanoindentation tests were carried out to measure the mechanical properties of the coating. Plasma characterization revealed the presence of CN molecules and Cr ions in the plasma. Surface spectroscopy results showed that ZrN, Zr 3N 4 and ZrC coexist in the coating. These results allowed the understanding of the mechanical behavior of the coatings, demonstrating the importance of the plasma characterization as a tool for tailoring the properties of hard coatings.

  7. Re-weldability of neutron irradiated Type 304 and 316L stainless steels

    NASA Astrophysics Data System (ADS)

    Morishima, Y.; Koshiishi, M.; Kashiwakura, K.; Hashimoto, T.; Kawano, S.

    2004-08-01

    Weldability of irradiated stainless steel (SS) has been studied to develop the technical guideline regarding the repair-welding of reactor internals. Type 304 and 316L SSs were irradiated at ambient temperature in the US Advanced Test Reactor. The multi-pass bead-on-plate TIG (GTA) and YAG laser welding with heat input levels less than 1 MJ/m were performed on specimens containing helium up to 18 appm. In this paper, results of cross-sectional micrograph observations of the heat affected zone were considered in light of helium bubble properties. The tendency for weld crack formation of irradiated Type 316L SS was compared with that of irradiated Type 304 SS.

  8. Elastic-plastic analysis of the SS-3 tensile specimen

    SciTech Connect

    Majumdar, S.

    1998-09-01

    Tensile tests of most irradiated specimens of vanadium alloys are conducted using the miniature SS-3 specimen which is not ASTM approved. Detailed elastic-plastic finite element analysis of the specimen was conducted to show that, as long as the ultimate to yield strength ratio is less than or equal to 1.25 (which is satisfied by many irradiated materials), the stress-plastic strain curve obtained by using such a specimen is representative of the true material behavior.

  9. Analysis of structure and deformation behavior of AISI 316L tensile specimens from the second operational target module at the Spallation Neutron Source

    SciTech Connect

    Gussev, Maxim N.; McClintock, David A.; Garner, Frank

    2015-08-05

    In an earlier publication, tensile testing was performed on specimens removed from the first two operational targets of the Spallation Neutron Source (SNS). There were several anomalous features in the results. First, some specimens had very large elongations (up to 57%) while others had significantly smaller values. Second, there was a larger than the usual amount of data scatter in the elongation results. Third, the stress-strain diagrams of nominally similar specimens spanned a wide range of behavior ranging from expected irradiation-induced hardening to varying levels of force drop after yield point and indirect signs of "traveling deformation wave" behavior associated with strain-induced martensite formation. To investigate the cause(s) of such variable tensile behavior, several specimens from Target 2, spanning the range of observed tensile behavior, were chosen for detailed microstructural examination using electron backscattering analysis (EBSD). It was also shown that the steel employed in the construction of the target contained an unexpected bimodal grain size distribution, containing very large out-of-specification grains surrounded by necklaces of grains of within-specification sizes. The large grains were frequently comparable to the width of the gauge section of the tensile specimen. Moreover, the propensity to form martensite during deformation was shown to be accelerated by radiation but also to be very sensitive to the relative orientation of the grains with respect to the tensile axis. Specimens having large grains in the gauge that were most favorably oriented for production of martensite strongly exhibited the traveling deformation wave phenomenon, while those specimens with less favorably oriented grains had lesser or no degree of the wave effect, thereby accounting for the larger than expected data scatter.

  10. Analysis of structure and deformation behavior of AISI 316L tensile specimens from the second operational target module at the Spallation Neutron Source

    DOE PAGESBeta

    Gussev, Maxim N.; McClintock, David A.; Garner, Frank

    2015-08-05

    In an earlier publication, tensile testing was performed on specimens removed from the first two operational targets of the Spallation Neutron Source (SNS). There were several anomalous features in the results. First, some specimens had very large elongations (up to 57%) while others had significantly smaller values. Second, there was a larger than the usual amount of data scatter in the elongation results. Third, the stress-strain diagrams of nominally similar specimens spanned a wide range of behavior ranging from expected irradiation-induced hardening to varying levels of force drop after yield point and indirect signs of "traveling deformation wave" behavior associatedmore » with strain-induced martensite formation. To investigate the cause(s) of such variable tensile behavior, several specimens from Target 2, spanning the range of observed tensile behavior, were chosen for detailed microstructural examination using electron backscattering analysis (EBSD). It was also shown that the steel employed in the construction of the target contained an unexpected bimodal grain size distribution, containing very large out-of-specification grains surrounded by necklaces of grains of within-specification sizes. The large grains were frequently comparable to the width of the gauge section of the tensile specimen. Moreover, the propensity to form martensite during deformation was shown to be accelerated by radiation but also to be very sensitive to the relative orientation of the grains with respect to the tensile axis. Specimens having large grains in the gauge that were most favorably oriented for production of martensite strongly exhibited the traveling deformation wave phenomenon, while those specimens with less favorably oriented grains had lesser or no degree of the wave effect, thereby accounting for the larger than expected data scatter.« less

  11. Analysis of structure and deformation behavior of AISI 316L tensile specimens from the second operational target module at the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Gussev, M. N.; McClintock, D. A.; Garner, F. A.

    2016-01-01

    In an earlier publication, tensile testing was performed on specimens removed from the first two operational targets of the Spallation Neutron Source (SNS). There were several anomalous features in the results. First, some specimens had very large elongations (up to 57%) while others had significantly smaller values (10-30%). Second, there was a larger than the usual amount of data scatter in the elongation results. Third, the stress-strain diagrams of nominally similar specimens spanned a wide range of behavior ranging from expected irradiation-induced hardening to varying levels of force drop after yield point and indirect signs of "traveling deformation wave" behavior associated with strain-induced martensite formation. To investigate the cause(s) of such variable tensile behavior, several specimens from Target 2, spanning the range of observed tensile behavior, were chosen for detailed microstructural examination using electron backscatter diffraction (EBSD) analysis. It was shown that the steel employed in the construction of the target contained an unexpected bimodal grain size distribution, containing very large out-of-specification grains surrounded by "necklaces" of grains of within-specification sizes. The large grains were frequently comparable to the width of the gauge section of the tensile specimen. The propensity to form martensite during deformation was shown to be accelerated by radiation but also to be very sensitive to the relative orientation of the grains with respect to the tensile axis. Specimens having large grains in the gauge that were most favorably oriented for production of martensite strongly exhibited the traveling deformation wave phenomenon, while those specimens with less favorably oriented grains had lesser or no degree of the wave effect, thereby accounting for the observed data scatter.

  12. Intragranular cellular segregation network structure strengthening 316L stainless steel prepared by selective laser melting

    NASA Astrophysics Data System (ADS)

    Zhong, Yuan; Liu, Leifeng; Wikman, Stefan; Cui, Daqing; Shen, Zhijian

    2016-03-01

    A feasibility study was performed to fabricate ITER In-Vessel components by Selective Laser Melting (SLM) supported by Fusion for Energy (F4E). Almost fully dense 316L stainless steel (SS316L) components were prepared from gas-atomized powder and with optimized SLM processing parameters. Tensile tests and Charpy-V tests were carried out at 22 °C and 250 °C and the results showed that SLM SS316L fulfill the RCC-MR code. Microstructure characterization reveals the presence of hierarchical macro-, micro- and nano-structures in as-built samples that were very different from SS316L microstructures prepared by other established methods. The formation of a characteristic intragranular cellular segregation network microstructure appears to contribute to the increase of yield strength without losing ductility. Silicon oxide nano-inclusions were formed during the SLM process that generated a micro-hardness fluctuation in the building direction. The combined influence of a cellular microstructure and the nano-inclusions constraints the size of ductile dimples to nano-scale. The crack propagation is hindered by a pinning effect that improves the defect-tolerance of the SLM SS316L. This work proves that it was possible to manufacture SS316L with properties suitable for ITER First Wall panels. Further studies on irradiation properties of SLM SS316L and manufacturing of larger real-size components are needed.

  13. Reducing Staphylococcus aureus biofilm formation on stainless steel 316L using functionalized self-assembled monolayers.

    PubMed

    Kruszewski, Kristen M; Nistico, Laura; Longwell, Mark J; Hynes, Matthew J; Maurer, Joshua A; Hall-Stoodley, Luanne; Gawalt, Ellen S

    2013-05-01

    Stainless steel 316L (SS316L) is a common material used in orthopedic implants. Bacterial colonization of the surface and subsequent biofilm development can lead to refractory infection of the implant. Since the greatest risk of infection occurs perioperatively, strategies that reduce bacterial adhesion during this time are important. As a strategy to limit bacterial adhesion and biofilm formation on SS316L, self-assembled monolayers (SAMs) were used to modify the SS316L surface. SAMs with long alkyl chains terminated with hydrophobic (-CH3) or hydrophilic (oligoethylene glycol) tail groups were used to form coatings and in an orthogonal approach, SAMs were used to immobilize gentamicin or vancomycin on SS316L for the first time to form an "active" antimicrobial coating to inhibit early biofilm development. Modified SS316L surfaces were characterized using surface infrared spectroscopy, contact angles, MALDI-TOF mass spectrometry and atomic force microscopy. The ability of SAM-modified SS316L to retard biofilm development by Staphylococcus aureus was functionally tested using confocal scanning laser microscopy with COMSTAT image analysis, scanning electron microscopy and colony forming unit analysis. Neither hydrophobic nor hydrophilic SAMs reduced biofilm development. However, gentamicin-linked and vancomycin-linked SAMs significantly reduced S. aureus biofilm formation for up to 24 and 48 h, respectively. PMID:23498233

  14. Mechanical and physical behavior of newly developed functionally graded materials and composites of stainless steel 316L with calcium silicate and hydroxyapatite.

    PubMed

    Ataollahi Oshkour, Azim; Pramanik, Sumit; Mehrali, Mehdi; Yau, Yat Huang; Tarlochan, Faris; Abu Osman, Noor Azuan

    2015-09-01

    This study aimed to investigate the structural, physical and mechanical behavior of composites and functionally graded materials (FGMs) made of stainless steel (SS-316L)/hydroxyapatite (HA) and SS-316L/calcium silicate (CS) employing powder metallurgical solid state sintering. The structural analysis using X-ray diffraction showed that the sintering at high temperature led to the reaction between compounds of the SS-316L and HA, while SS-316L and CS remained intact during the sintering process in composites of SS-316L/CS. A dimensional expansion was found in the composites made of 40 and 50 wt% HA. The minimum shrinkage was emerged in 50 wt% CS composite, while the maximum shrinkage was revealed in samples with pure SS-316L, HA and CS. Compressive mechanical properties of SS-316L/HA decreased sharply with increasing of HA content up to 20 wt% and gradually with CS content up to 50 wt% for SS-316L/CS composites. The mechanical properties of the FGM of SS-316L/HA dropped with increase in temperature, while it was improved for the FGM of SS-316L/CS with temperature enhancement. It has been found that the FGMs emerged a better compressive mechanical properties compared to both the composite systems. Therefore, the SS-316L/CS composites and their FGMs have superior compressive mechanical properties to the SS-316L/HA composites and their FGMs and also the newly developed FGMs of SS-316L/CS with improved mechanical and enhanced gradation in physical and structural properties can potentially be utilized in the components with load-bearing application. PMID:26072197

  15. Effect of ITER components manufacturing cycle on the irradiation behaviour of 316L(N)-IG steel

    NASA Astrophysics Data System (ADS)

    Rodchenkov, B. S.; Prokhorov, V. I.; Makarov, O. Yu; Shamardin, V. K.; Kalinin, G. M.; Strebkov, Yu. S.; Golosov, O. A.

    2000-12-01

    The main options for the manufacturing of high heat flux (HHF) components is hot isostatic pressing (HIP) using either solid pieces or powder. There was no database on the radiation behaviour of these materials, and in particular stainless steel (SS) 316L(N)-IG with ITER components manufacturing thermal cycle. Irradiation of wrought steel, powder-HIP, solid-HIP and HIPed joints has been performed within the framework of an ITER task. Specimens cut from 316L(N)-IG plate, HIP products, and solid-HIP joints were irradiated in the SM-3 reactor in Dimitrovgrad up to 4 and 10 dpa at 175°C and 265°C. The paper describes the results of post-irradiation tensile and fracture toughness tests.

  16. Improved anticorrosion properties and electrical conductivity of 316L stainless steel as bipolar plate for proton exchange membrane fuel cell by lower temperature chromizing treatment

    NASA Astrophysics Data System (ADS)

    Yang, Lijun; Yu, Haijun; Jiang, Lijun; Zhu, Lei; Jian, Xuyu; Wang, Zhong

    The lower temperature chromizing treatment is developed to modify 316L stainless steel (SS 316L) for the application of bipolar plate in proton exchange membrane fuel cell (PEMFC). The treatment is performed to produce a coating, containing mainly Cr-carbide and Cr-nitride, on the substrate to improve the anticorrosion properties and electrical conductivity between the bipolar plate and carbon paper. Shot peening is used as the pretreatment to produce an activated surface on stainless steel to reduce chromizing temperature. Anticorrosion properties and interfacial contact resistance (ICR) are investigated in this study. Results show that the chromized SS 316L exhibits better corrosion resistance and lower ICR value than those of bare SS 316L. The chromized SS 316L shows the passive current density about 3E-7 A cm -2 that is about four orders of magnitude lower than that of bare SS 316L. ICR value of the chromized SS 316L is 13 mΩ cm 2 that is about one-third of bare SS 316L at 200 N cm -2 compaction forces. Therefore, this study clearly states the performance advantages of using chromized SS 316L by lower temperature chromizing treatment as bipolar plate for PEMFC.

  17. Influence of Prior Fatigue Damage on Tensile Properties of 316L(N) Stainless Steel and Modified 9Cr-1Mo Steel

    NASA Astrophysics Data System (ADS)

    Mariappan, K.; Shankar, Vani; Sandhya, R.; Mathew, M. D.; Bhaduri, A. K.

    2015-02-01

    In the current study, the effect of prior low-cycle fatigue (LCF) damage on the tensile properties of 316L(N) stainless steel (SS) and modified 9Cr-1Mo steel were systematically investigated. The LCF tests were interrupted at 5, 10, 30, and 50 pct of the total fatigue life followed by tensile tests on the same specimens at the same strain rate (3 × 10-3 s-1) and temperatures of 300 K, 823 K, and 873 K (27 °C, 550 °C, and 600 °C). Prior strain cycling at elevated temperatures had remarkable effect on the tensile properties of both cyclically hardening and cyclically softening materials. An exponential relationship between the yield stress and the amount of pre-strain cycles is obtained for both the materials. The initial drastic change in the yield strength values up to 10 pct of fatigue life may be due to the microstructural changes that lead to hardening or softening in 316L(N) SS and modified 9Cr-1Mo steel, respectively. Saturation in the yield strength values beyond 10 pct of fatigue life has practical importance for remnant fatigue life assessment. Evolution of fatigue damage in both the 316L(N) SS and modified 9Cr-1Mo steel was analyzed using the surface replica technique.

  18. Mechanical properties of F82H/316L and 316L/316L welds upon the target back-plate of IFMIF

    NASA Astrophysics Data System (ADS)

    Furuya, Kazuyuki; Ida, Mizuho; Miyashita, Makoto; Nakamura, Hiroo

    2009-04-01

    The current material design of the International fusion materials irradiation facility (IFMIF) back-plate in Japan consists of an austenitic stainless steel type-316L and a RAF/M steel type-F82H. The 316L and F82H are welded together. The 316L region of the back-plate is also welded to the target assembly made of 316L. The back-plate operates under a severe neutron irradiation condition (50 dpa/year). Therefore, it is important to perform metallurgical and mechanical tests for these welds in engineering design of the IFMIF. The F82H/316L weld joint with a filler metal type-Y309 was fabricated using TIG-welding method, followed by PWHT at 1013 K for 1 h. The 316L/316L weld joint was fabricated using YAG-laser welding method. The F82H/316L TIG-weld was found to be satisfactory. However, although the 316L/316L YAG-weld showed no harmful defect, the hardness was somewhat lower in the weld metal. Rupture occurred in the weld metal, and strength and elongation decreased somewhat. Furthermore, small dimples with several large voids were also visible in the fracture surface.

  19. Mechanical and substructural response of incipiently spalled 316L stainless steel.

    SciTech Connect

    Gray, G. T. , III; Bourne, N. K.

    2004-01-01

    316L SS samples were shock prestrained to a peak stress of 6.6 GPa using a 0.75 {mu}sec pulse duration square-topped shock profile and 'soft' recovered while a second sample was similarly shock loaded, without spall momentum trapping, leading to incipient spall damage. Shock prestraining and 'soft' shock recovery to 6.6 GPa led to an increase in the post-shock flow strength of 316L SS by {approx}100 MPa over the starting material while the reload yield strength of the incipiently spall damaged sample increased by {approx}200 MPa. In this paper the sequential processes of defect generation and damage operative during the shock prestraining, spallation, and reloading of incipiently spalled 316L SS is presented. The influence of shock prestraining, using both triangular-wave loading, via both direct HE and triangular-wave pulses on a gas launcher, as well as 'square-topped' shock prestaining via conventional flyer-plate impact, is crucial to understanding the shock hardening and spallation responses of materials(Gray III, et al. [2003]). The development of predictive constitutive models to describe the mechanical response of incipiently damaged metals and alloys requires an understanding of the defect generation and storage due to shock hardening as well as the additional plasticity and damage evolution during spallation. In this paper the influence of shock-wave prestraining on the process of shock hardening and thereafterthe hardeningand damage evolution accompanying incipient spallation in 316L stainless steel (316L SS) on post-shock constitutive behavior is examined using 'soft' recovery techniques and mechanical behavior measurements.

  20. Damage mechanism at different transpassive potentials of solution-annealed 316 and 316l stainless steels

    NASA Astrophysics Data System (ADS)

    Morshed Behbahani, K.; Pakshir, M.; Abbasi, Z.; Najafisayar, P.

    2015-01-01

    Electrochemical impedance spectroscopy (EIS), anodic polarization and scanning electron microscopy techniques were used to investigate the damage mechanism in the transpassive potential region of AISI 316 and AISI 316L solution-annealed stainless steels (SS) with different degrees of sensitization. Depending on the DC potential applied during EIS tests, the AC responses in the transpassive region included three different regions: the first one associated with anodic dissolution of the passive layer, the second one contributed to the dissolution at the area near grain boundaries, and the last one attributed to pitting corrosion. In addition, the fitting results to experimental data showed that as the DC bias during the EIS test increases the charge transfer resistance ( R ct) decreases. Moreover, the R ct values decreased as the sensitization temperature increases but the AISI 316L SS samples exhibited a higher resistance to intergranular corrosion than 316 SS samples.

  1. Surface characterisation and electrochemical behaviour of porous titanium dioxide coated 316L stainless steel for orthopaedic applications

    NASA Astrophysics Data System (ADS)

    Nagarajan, S.; Rajendran, N.

    2009-01-01

    Porous titanium dioxide was coated on surgical grade 316L stainless steel (SS) and its role on the corrosion protection and enhanced biocompatibility of the materials was studied. X-ray diffraction analysis (XRD), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX) were carried out to characterise the surface morphology and also to understand the structure of the as synthesised coating on the substrates. The corrosion behaviour of titanium dioxide coated samples in simulated body fluid was evaluated using polarisation and impedance spectroscopy studies. The results reveal that the titanium dioxide coated 316L SS exhibit a higher corrosion resistance than the uncoated 316L SS. The titanium dioxide coated surface is porous, uniform and also it acts as a barrier layer to metallic substrate and the porous titanium dioxide coating induces the formation of hydroxyapatite layer on the metal surface.

  2. Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment

    SciTech Connect

    Wire, G. L.; Mills, W. J.

    2002-08-01

    Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.

  3. Investigation into the joining of MoSi{sub 2} to 316L stainless steel

    SciTech Connect

    Vaidya, R.U.; Bartlett, A.H.; Conzone, S.D.; Butt, D.P.

    1996-10-01

    Partial transient liquid phase joining and low temperature brazing were applied in joining MoSi{sub 2} to 316L ss. Exploratory studies were carried out on various interlayer materials. Mechanical, physical, and chemical compatibilities between various interlayers, brazing material, and substrate materials were investigated. Effect of thermal expansion mismatch between various components of the joint on the overall joint integrity was also studied. Preliminary findings are outlined.

  4. Effect of Mercury Velocity on Corrosion of Type 316L Stainless Steel in a Thermal Convection Loop

    SciTech Connect

    Pawel, SJ

    2001-03-23

    Two 316L thermal convection loops (TCLs) containing several types of 316L specimens circulated mercury continuously for 2000 h at a maximum temperature of 300 C. Each TCL was fitted with a venturi-shaped reduced section near the top of the hot leg for the purpose of locally increasing the Hg velocity. Results suggest that an increase in velocity from about 1.2 m/min (bulk flow) to about 5 mmin (reduced section) had no significant impact on compatibility of 316L with Hg. In addition, various surface treatments such as gold-plating, chemical etching, polishing, and steam cleaning resulted in little or no influence on compatibility of 316L with Hg when compared to nominal mill-annealed/surface-ground material. A sensitizing heat treatment also had little/no effect on compatibility of 316L with Hg for the bulk specimen, although intergranular attack was observed around the specimen holes in each case. It was determined that carburization of the hole area had occurred as a result of the specimen fabrication process potentially rendering the specimens susceptible to corrosion by Hg at these locations. To avoid sensitization-related compatibility issues for SNS components, selection of low carbon grades of stainless steel and control of the fabrication process is recommended.

  5. Rapid heating tensile tests of hydrogen-charged high-energy-rate-forged 316L stainless steel

    SciTech Connect

    Mosley, W.C.

    1989-05-19

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. Proper design of the equipment will require an understanding of how tritium and its decay product helium affect mechanical properties. This memorandum describes results of rapid heating tensile testing of hydrogen-charged specimens of high-energy-rate-forged (HERF) 316L stainless steel. These results provide a data base for comparison with uncharged and tritium-charged-and-aged specimens to distinguish the effects of hydrogen and helium. Details of the experimental equipment and procedures and results for uncharged specimens were reported previously. 3 refs., 10 figs.

  6. Creep deformation and fracture behavior of types 316 and 316L(N) stainless steels and their weld metals

    NASA Astrophysics Data System (ADS)

    Sasikala, G.; Mannan, S. L.; Mathew, M. D.; Rao, K. Bhanu

    2000-04-01

    The creep properties of a nuclear-grade type 316(L) stainless steel (SS) alloyed with nitrogen (316L(N) SS) and its weld metal were studied at 873 and 923 K in the range of applied stresses from 100 to 335 MPa. The results were compared with those obtained on a nuclear-grade type 316 SS, which is lean in nitrogen. The creep rupture lives of the weld metals were found to be lower than those of the respective base metals by a factor of 5 to 10. Both the base and weld metals of 316L(N) SS exhibited better resistance to creep deformation compared to their 316 SS counterparts at identical test conditions. A power-law relationship between the minimum creep rate and applied stress was found to be obeyed for both the base and weld metals. Both the weld metals generally exhibited lower rupture elongation than the respective base metals; however, at 873 K, the 316 SS base and weld metals had similar rupture elongation at identical applied stresses. Comparison of the rupture lives of the two steels to the ASME curves for the expected minimum stress to rupture for 316 SS base and weld metals showed that, for 316L(N) SS, the specifications for maximum allowable stresses based on data for 316 SS could prove overconservative. The influence of nitrogen on the creep deformation and fracture behavior, especially in terms of its modifying the precipitation kinetics, is discussed in light of the microstructural observations. In welds containing δ ferrite, the kinetics of its transformation and the nature of the transformation products control the deformation and fracture behavior. The influence of nitrogen on the δ ferrite transformation behavior and coarsening kinetics is also discussed, on the basis of extensive characterization by metallographic techniques.

  7. Corrosion behaviour of 316L stainless steel and anti-corrosion materials in a high acidified chloride solution

    NASA Astrophysics Data System (ADS)

    Jin, Z. H.; Ge, H. H.; Lin, W. W.; Zong, Y. W.; Liu, S. J.; Shi, J. M.

    2014-12-01

    The corrosion behaviour of a type 316L (UNS S31603) stainless steel (SS) expansion joint in a simulated leaching solution of sediment on blast furnace gas pipeline in a power plant is investigated by using dynamic potential polarization curves, electrochemical impedance spectroscopy (EIS), optical microscope, atomic force microscope (AFM) and Scan Kelvin Probe (SKP). Severe general corrosion accompanied by pitting corrosion occurs on the type 316L SS surface in this solution. As the immersion period increases, the charge transfer resistance Rct decreases, the dissolution rate accelerates, the surface roughness increases and the surface potential difference enhances significantly. Then eight corrosion-resistant materials are tested, the corrosion rates of type 254SMo SS, type 2507 SS and TA2 are relatively minor in the solution. The corrosion resistance properties of TA2 is most excellent, indicating it would be the superior material choice for blast furnace gas pipeline.

  8. Cobalt-Free Laser Cladding on AISI Type 316L Stainless Steel for Improved Cavitation and Slurry Erosion Wear Behavior

    NASA Astrophysics Data System (ADS)

    Paul, C. P.; Gandhi, B. K.; Bhargava, P.; Dwivedi, D. K.; Kukreja, L. M.

    2014-09-01

    Laser cladding of Colmonoy-5 (a nickel base alloy) and Metco-41C (an iron base alloy) on AISI type 316L stainless steel (SS316L) and their wear behaviors were investigated to establish Co-free clad layers for potential applications in nuclear industry. A 3.5 kW CO2 laser-based system was used to optimize the laser cladding on SS316L substrate. The observed optimum parameters were: laser power of 1.6 kW, scan speed of 0.6 m/min, and powder feed rate of 8 g/min with 60% overlapping. The microstructure studies revealed that the clad layers primarily comprise very fine columnar dendritic structures, while clad-substrate interface exhibited planar and non-epitaxial mode of solidification due to high cooling rates. The cavitation and slurry erosion behaviors of laser clad layers were also compared to that of Stellite-6 for potential direct replacement. The cavitation erosion resistance was improved by a factor of 1.6, 3.7, and 4.1, while the slurry erosion resistances at an impingement angle of 30° were 1.5, 4.8, and 1.8 times better for laser clad surfaces of Colmonoy-5, Metco-41C, and Stellite-6, respectively, as compared to that of bare SS316L substrate. The study demonstrated that Metco-41C is a better choice as Co-free clad material for potential nuclear applications.

  9. Cobalt-Free Laser Cladding on AISI Type 316L Stainless Steel for Improved Cavitation and Slurry Erosion Wear Behavior

    NASA Astrophysics Data System (ADS)

    Paul, C. P.; Gandhi, B. K.; Bhargava, P.; Dwivedi, D. K.; Kukreja, L. M.

    2014-12-01

    Laser cladding of Colmonoy-5 (a nickel base alloy) and Metco-41C (an iron base alloy) on AISI type 316L stainless steel (SS316L) and their wear behaviors were investigated to establish Co-free clad layers for potential applications in nuclear industry. A 3.5 kW CO2 laser-based system was used to optimize the laser cladding on SS316L substrate. The observed optimum parameters were: laser power of 1.6 kW, scan speed of 0.6 m/min, and powder feed rate of 8 g/min with 60% overlapping. The microstructure studies revealed that the clad layers primarily comprise very fine columnar dendritic structures, while clad-substrate interface exhibited planar and non-epitaxial mode of solidification due to high cooling rates. The cavitation and slurry erosion behaviors of laser clad layers were also compared to that of Stellite-6 for potential direct replacement. The cavitation erosion resistance was improved by a factor of 1.6, 3.7, and 4.1, while the slurry erosion resistances at an impingement angle of 30° were 1.5, 4.8, and 1.8 times better for laser clad surfaces of Colmonoy-5, Metco-41C, and Stellite-6, respectively, as compared to that of bare SS316L substrate. The study demonstrated that Metco-41C is a better choice as Co-free clad material for potential nuclear applications.

  10. Anticoagulant surface of 316 L stainless steel modified by surface-initiated atom transfer radical polymerization.

    PubMed

    Guo, Weihua; Zhu, Jian; Cheng, Zhenping; Zhang, Zhengbiao; Zhu, Xiulin

    2011-05-01

    Polished 316 L stainless steel (SS) was first treated with air plasma to enhance surface hydrophilicity and was subsequently allowed to react with 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane to introduce an atom transfer radical polymerization (ATRP) initiator. Accordingly, the surface-initiated atom transfer radical polymerization of polyethylene glycol methacrylate (PEGMA) was carried out on the surface of the modified SS. The grafting progress was monitored by water contact angle measurements, X-ray photoelectron spectroscopy and atomic force microscopy. The polymer thickness as a function different polymerization times was characterized using a step profiler. The anticoagulative properties of the PEGMA modified SS surface were investigated. The results showed enhanced anticoagulative to acid-citrate-dextrose (ACD) blood after grafting PEGMA on the SS surface. PMID:21528878

  11. 316L stainless steel tubes corrosion influenced by SRB in sea water

    SciTech Connect

    Yoffe, P.

    1997-08-01

    A tube made from SS316L was attacked by stagnated sea water. The typical onion form of the pits were obscured in welded and unwelded sectors of the tube. Iron sulfides FeS{sub 1{minus}x} and FeS{sub 2} (in pyrite form) were observed on effected surface of the tube, in addition to iron chloride and oxide/hydroxide. Theoretical investigation was based on cluster model of alloy and thermodynamic/kinetic characterization of possible reactions. It was concluded that microbially influenced sulfidizing played an accelerating role in the failure that exhibited the typical characteristics for stagnated sea water effect to chromium-nickel stainless steel.

  12. Creep deformation and fracture behavior of types 316 and 316L(N) stainless steels and their weld metals

    SciTech Connect

    Sasikala, G.; Mathew, M.D.; Bhanu Sankara Rao, K.; Mannan, S.L.

    2000-04-01

    The creep properties of a nuclear-grade type 316(L) stainless steel (SS) alloyed with nitrogen (316L(N)SS) and its weld metal were studied at 873 and 923 K in the range of applied stresses from 100 to 335 MPa. The results were compared with those obtained on a nuclear-grade type 316 SS, which is lean in nitrogen. The creep rupture lives of the weld metals were found to be lower than those of the respective base metals by a factor of 5 to 10. Both the base and weld metals of 314L(N)SS exhibited better resistance to creep deformation compared to their 316SS counterparts at identical test conditions. A power-law relationship between the minimum creep rate and applied stress was found to be obeyed for both the base and weld metals. Both the weld metals generally exhibited lower rupture elongation than the respective base metals; however, at 873 K, the 316 SS base and weld metals had similar rupture elongation at identical applied stresses. Comparison of the rupture lives of the two steels to the ASME curves for the expected minimum stress to rupture for 316 Ss base and weld metals showed that, for 316L(N) SS, the specifications for maximum allowable stresses based on data for 316 SS could prove overconservative. The influence of nitrogen on the creep deformation and fracture behavior, especially in terms of its modifying the precipitation kinetics, is discussed in light of the microstructural observations. In welds containing {delta} ferrite, the kinetics of its transformation and the nature of the transformation products control the deformation and fracture behavior. The influence of nitrogen on the {delta} ferrite transformation behavior and coarsening kinetics is also discussed, on the basis of extensive characterization by metallographic techniques.

  13. Cytocompatibility and mechanical properties of novel porous 316 L stainless steel.

    PubMed

    Kato, Komei; Yamamoto, Akiko; Ochiai, Shojiro; Wada, Masahiro; Daigo, Yuzo; Kita, Koichi; Omori, Kenichi

    2013-07-01

    Novel 316 L stainless steel (SS) foam with 85% porosity and an open pore diameter of 70-440 μm was developed for hard tissue application. The foam sheet with a 200-μm diameter had superior cell proliferation and penetration as identified through in vitro experiments. Calcification of human osteosarcoma cells in the SS foam was observed. Multi-layered foam preparation is a potential alternative technique that satisfies multi-functional requirements such as cell penetration and binding strength to the solid metal. In tensile tests, Young's modulus and the strength of the SS foam were 4.0 GPa and 11.2 MPa respectively, which is comparable with human cancellous bone. PMID:23623090

  14. Effect of thermal exposure in helium on mechanical properties and microstructure of 316L and P91

    NASA Astrophysics Data System (ADS)

    Kunzova, Klara; Berka, Jan; Siegl, Jan; Hausild, Petr

    2016-04-01

    In this paper, the effects of high temperature exposure in air as well as in impure He on mechanical properties of 316L and P91 steels were investigated. The experimental programme was part of material design of new experimental facility - high temperature helium loop. Some of the specimens were exposed in air at 750 °C for up to 1000 h. Another set of specimens were exposed in impure helium containing 1 ppmv CO2, 2 ppmv O2, 35 ppmv CH4, 250 ppmv CO and 400 ppmv H2 at 750 °C for up to 1000 h. Metalographical analysis, tensile tests, fracture toughness and hardness tests of exposed and non-exposed specimens were carried out. After the exposure both in air and He, the ultimate tensile strength of P91 decreased significantly more than that of 316L. After the exposure in He, the fracture toughness of 316L was reduced to 60% while fracture toughness of P91 showed no significant changes. The hardness of P91 decreased with exposure time in air. The measurement of the hardness of 316L was very scattered the most probably due to the heterogeneities in microstructure, the trend was not possible to evaluate.

  15. Selective surface preoxidation to inhibit the corrosion of AISI type 316L stainless steel by liquid Pb17Li

    NASA Astrophysics Data System (ADS)

    Sample, T.; Coen, V.; Kolbe, H.; Orecchia, L.

    1992-09-01

    This paper describes the formation of a ternary oxide coating on 316L stainless steel from the reaction of Pb17Li with the preoxidized surface of steel specimens. The preoxidized surfaces were prepared by heating 316L stainless steel specimens to 800°C in a controlled H2/H2O atmosphere (ratio 1000:1). The oxide layer before reaction with the Pb17Li was characterized as Mn1.5Cr1.5P4. Analysis after reaction with Pb17Li indicated a LiMn2O4 structure with some of the manganese sites occupied by chromium.316L specimens prepared with different oxide layer thicknesses, along with uncoated specimens, were corroded in the isothermal hot legs of two Pb17Li filled thermal convection loops.Post-test analysis of the specimens indicated that the oxide coated specimens had, on average, a thinner ferritic corrosion layer than the uncoated specimens. The coated specimens also showed areas with no ferritic corrosion layer.

  16. On the corrosion resistance of AISI 316L-type stainless steel coated with manganese and annealed with flow of oxygen

    NASA Astrophysics Data System (ADS)

    Savaloni, Hadi; Agha-Taheri, Ensieh; Abdi, Fateme

    2016-06-01

    AISI 316L-type stainless steel was coated with 300-nm-thick Mn thin films and post-annealed at 673 K with a constant flow of oxygen (250 cm3/min). The films crystallographic and morphological structures were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM) before corrosion test and scanning electron microscopy (SEM) after corrosion test. Corrosion behavior of the samples in 0.3, 0.5 and 0.6 M NaCl solutions was investigated by means of potentiodynamic and electrochemical impedance spectroscopy (EIS) techniques. Results showed that the corrosion inhibition of annealed Mn/SS316L in all NaCl solutions with different concentrations is higher than that of bare SS316L. A correlation is achieved between the structural variation of the films with the potentiodynamic and EIS corrosion results.

  17. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    NASA Astrophysics Data System (ADS)

    Shibata, K.; Fujii, H.

    2004-06-01

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation.

  18. Notch Effect on Tensile Deformation Behavior of 304L and 316L Steels in Liquid Helium and Hydrogen

    SciTech Connect

    Shibata, K.; Fujii, H.

    2004-06-28

    Tensile tests of type 304L and 316L steels were carried out using round bar specimens with a notch in liquid helium, hydrogen, liquid nitrogen and at ambient temperature. The obtained tensile strengths were compared with the tensile strengths of smooth specimens. For smooth specimens, tensile strength increased with a decrease in temperature and the strengths in liquid helium and hydrogen show similar values in both steels. For notched specimen of 304L steel, tensile strength (including fracture strength) increased noticeably from ambient to liquid nitrogen temperature but showed a large decrease in liquid helium and hydrogen. In liquid hydrogen and helium, the tensile strength is a little lower in liquid hydrogen than in liquid helium and both strengths are lower than tensile strengths of smooth specimens. For notched specimen of 316L steel, an increase in tensile strength from ambient to liquid nitrogen temperature was not so large and a decrease from liquid nitrogen to liquid hydrogen was small. The tensile strengths in liquid helium and hydrogen were nearly same and higher than those of smooth specimens. Different behavior of serration was observed between liquid helium and hydrogen, and between 304L and 316L steels. The reasons for these differences were discussed using computer simulation.

  19. Pitting corrosion behavior of 316L stainless steel in the media of sulphate-reducing and iron-oxidizing bacteria

    SciTech Connect

    Xu Congmin; Zhang Yaoheng; Cheng Guangxu Zhu Wensheng

    2008-03-15

    Pitting corrosion behavior of 316L SS was investigated in the presence of aerobic and anaerobic bacteria isolated from cooling water system in oil refinery using polarization measurement, electrochemical impedance spectroscopy, scanning electron microscopy examinations and energy dispersive spectrum analysis. The results show the corrosion potential (E{sub corr}), pitting potential (E{sub pit}) and polarization resistance (R{sub P}) of 316L SS had a distinct decrease in the presence of bacteria, in comparison with those observed in the sterile medium for the same exposure time interval. Micrometer-scale pitting was observed on the 316L SS surface in the presence of bacteria. The combination of SRB and IOB demonstrated higher corrosion rates than SRB or IOB alone. The synergy of 0.01 M NaCl + SRB + IOB yielded the highest corrosion rate. The synergies between the metal surface, abiotic corrosion products, chloride anion, and bacterial cells and their metabolic products increased the corrosion damage degree of the passive film and accelerated pitting propagation.

  20. Plasma-sprayed yttria-stabilized zirconia coatings on type 316L stainless steel for pyrochemical reprocessing plant

    NASA Astrophysics Data System (ADS)

    Ravi Shankar, A.; Kamachi Mudali, U.; Sole, Ravikumar; Khatak, H. S.; Raj, Baldev

    2008-01-01

    Type 316L stainless steel (SS) is one of the candidate materials proposed for application in pyrochemical reprocessing plants. In the present work, yttria-stabilized zirconia coatings of 300 μm were applied over type 316L SS with a metallic bond coating of 50 μm by an optimized plasma spray process, and were assessed for the corrosion behaviour in molten LiCl-KCl medium at 873 K for periods of 5 h, 100 h, 250 h and 500 h. The as-coated and tested samples were examined by optical microscopy and SEM for homogeneity, penetration of molten salt through coating and corrosion of type 316L SS substrate. The results indicated that the yttria-stabilized zirconia coatings performed well without significant degradation and corrosion attack. Laser melting of the coated samples using CO 2 laser was attempted to consolidate the coatings. The development of large grains with segmented cracks was noticed after laser melting, though the coating defects have been eliminated.

  1. Tensile, low cycle fatigue and fracture toughness behaviour of type 316L steel irradiated to 0.3 dpa

    NASA Astrophysics Data System (ADS)

    Josefsson, Bertil; Bergenlid, Ulf

    1994-09-01

    The effect of a low dose neutron irradiation on the tensile, low cycle fatigue and fracture toughness properties of type 316L steel plate and weld material was investigated. The specimens were irradiated at a temperature of about 35°C to a neutron fluence of approximately 2.5 × 10 20 n/cm 2 ( E > 1 MeV). The testing was performed at 75, 250 and 450°C. Irradiated tensile specimens showed a substantial radiation hardening combined with some reduction of elongations. There was no significant effect of the irradiation on the low cycle fatigue endurances. The fracture toughness of the TIG weld specimens was roughly half of that of the 316L plate and electron beam weld. Some reductions of toughness owing to the irradiation were observed.

  2. Compatibility of AISI 316 L stainless steel with the Li 17Pbg, eutectic

    NASA Astrophysics Data System (ADS)

    Coen, V.; Fenici, P.; Kolbe, H.; Orecchia, L.; Sasaki, T.

    1982-09-01

    The compatibility of AISI 316 L stainless steel with the Li 17Pb 83, eutectic has been studied in the temperature range 623-873 K for times up to 6000 h. In the corrosion layers formed there is a strong Ni depletion and Pb and Li penetration in the matrix. Tests at 623 K in Li 17Pb 83 on notched tensile specimens under a constant uniaxial tensile load, below the engineering yield stress, have evidenced that. many cracks filled with Pb and possibly Li are formed after relatively short times.

  3. Effect of Laser Peening without Coating on 316L austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Sathyajith, S.; kalainathan, S.

    2015-02-01

    Laser Peening without Coating (LPwC) is an innovative surface modification technique used for the in-suit preventive maintenance of nuclear reactor components using frequency doubled (green) laser. The advantage of LPwC is that the laser required for this technique is in milli joule range and the processes can perform in aqueous environment. This paper discussed the effect of LPwC on 316L austenitic stainless steel using low energy Nd: YAG laser with various laser pulse density. The base specimen and laser peened specimen were subjected to surface residual stress, surface morphology, micro hardness and potentiodynamic polarization studies. The laser peened surface exhibit significant improvement in surface compressive residual stress. The depth profile of micro hardness revealed higher strain hardening on laser peened specimens. Though corrosion potential reported an anodic shift,current density is found to be increased after LPwC for the specimen peened with higher pulse density.

  4. Wear Resistance of AISI316L Steel Modified by Pre-FPP Treated DLC Coating

    NASA Astrophysics Data System (ADS)

    Nanbu, Hiroshi; Kikuchi, Shoichi; Kameyama, Yutaka; Komotori, Jun

    In order to improve the adhesion strength of the DLC coating, Fine Particle Peening (FPP) treatment was employed as pretreatment for DLC coatings. FPP treatment was performed using SiC shot particles, and then the AISI316L steel was DLC-coated. The FPP treatment increased the surface roughness of the specimen, and a Si-rich layer was formed on the surface because of the mechanical mixing of SiC shot particles into the steel substrate. Reciprocating sliding wear tests were conducted to measure the friction coefficient. While the non-pretreated (only DLC-coated) specimens showed a sudden increase in friction coefficient resulting from delamination of the DLC coating, the pre-FPP-treated specimens maintained a low friction coefficient during the wear tests. This indicates the strong adhesion of the DLC coating of the pre-FPP-treated specimen caused by the increase in surface roughness and the presence of Si on the surface.

  5. Effect of irradiation dose on mechanical properties and fracture character of Cu//SS joints for ITER

    NASA Astrophysics Data System (ADS)

    Pokrovsky, A. S.; Fabritsiev, S. A.; Peacock, A.; Gerwash, A.; Barabash, V. R.

    2007-08-01

    Cu//SS type joints are essential for the heat-sink systems of the ITER high-heat flux components. A number of technologies have been proposed for the production of such bimetallic structures, including brazing, friction welding, HIP and cast-copper-to-steel. In this paper, the authors present the results of investigations into the irradiation resistance of GlidCopAl25//316L(N) and CuCrZr//316L(N)-type joints produced by the HIP and cast-copper-to-steel (CC) technologies. Specimens of the joints were irradiated in the RBT-6 reactor in the dose range of 10 -3-10 -1 dpa at Tirr = 150 °C. Irradiation causes strengthening of the joint specimens and the uniform elongation drops from 7% in the initial state to 1-2%. However, the total elongation remains at the relatively high level of ˜10%. The investigations performed make it possible to recommend joints of CuCrZr//316L(N) (CC) and CuCrZr//316L(N) (HIP) type produced by the cast-copper-to-steel and HIP technologies, respectively, for ITER applications.

  6. Repassivation behavior of 316L stainless steel in borate buffer solution: Kinetics analysis of anodic dissolution and film formation

    NASA Astrophysics Data System (ADS)

    Xu, Haisong; Sun, Dongbai; Yu, Hongying

    2015-12-01

    The repassivation behavior of metals or alloys after oxide film damage determines the development of local corrosion and corrosion resistance. In this work, the repassivation kinetics of 316L stainless steel (316L SS) are investigated in borate buffer solution (pH 9.1) by using the abrading electrode technique. The current densities flowing from bare 316L SS surface are measured by potentiostatic method and analyzed to characterize repassivation kinetics. The initial stages of current decay (t < 500 ms) are discussed according to a film growth model, which describes the initial current transient should be divided into substrate dissolution current and passive film formation current based on Avrami kinetics. Then the two independent components are analyzed individually. The film formation rate and the thickness of film are compared in different applied potential. It is shown that anodic dissolution dominates the repassivation for a short time during the early times, and a higher applied potential will promote the anodic dissolution of metal. The film growth rate increases slightly with increasing in potential. Correspondingly, increase in applied potential from 0 VSCE to 0.8 VSCE results in thicker monolayer, which covers the whole bare surface at the time of θ = 1. The electric field strengths through the thin passive film could reach 3.97 × 106 V cm-1.

  7. Improving the oxidation resistance of 316L stainless steel in simulated pressurized water reactor primary water by electropolishing treatment

    NASA Astrophysics Data System (ADS)

    Han, Guangdong; Lu, Zhanpeng; Ru, Xiangkun; Chen, Junjie; Xiao, Qian; Tian, Yongwu

    2015-12-01

    The oxidation behavior of 316L stainless steel specimens after emery paper grounding, mechanical polishing, and electropolishing were investigated in simulated pressurized water reactor primary water at 310 °C for 120 and 500 h. Electropolishing afforded improved oxidation resistance especially during the early immersion stages. Duplex oxide films comprising a coarse Fe-rich outer layer and a fine Cr-rich inner layer formed on all specimens after 500 h of immersion. Only a compact layer was observed on the electropolished specimen after 120 h of immersion. The enrichment of chromium in the electropolished layer contributed to the passivity and protectiveness of the specimen.

  8. Influence of Prior Deformation on the Sensitization Kinetics of Nitrogen Alloyed 316L Stainless Steels

    NASA Astrophysics Data System (ADS)

    Mannepalli, Srinivas; Gupta, Ram Kishor; Kumar, A. Vinod; Parvathavarthini, N.; Mudali, U. Kamachi

    2015-05-01

    This paper presents the influence of prior deformation on the sensitization kinetics of nitrogen-alloyed 316L stainless steels. Systematic investigations were carried out for two varieties of 316L SS containing (i) 0.025% C and 0.14% N; (ii) 0.033% C and 0.11% N. Using ASTM standard A262 Practice A and E tests, time-temperature-sensitization diagrams were constructed for as-received as well as 5-25% cold-worked materials. Using these TTS diagrams, critical cooling rates (CCR) above which there is no risk of sensitization were calculated. TTS diagrams established for these two stainless steels will be useful for avoiding time-temperature combinations that may result in sensitization and susceptibility to IGC. These CCR obtained can be used to optimize heating rates/cooling rates to be followed which will not lead to sensitization during solution annealing, stress-relieving, and dimensional stabilization of critical components for fast breeder reactors.

  9. Microstructural origins of radiation-induced changes in mechanical properties of 316 L and 304 L austenitic stainless steels irradiated with mixed spectra of high-energy protons and spallation neutrons

    NASA Astrophysics Data System (ADS)

    Sencer, B. H.; Bond, G. M.; Hamilton, M. L.; Garner, F. A.; Maloy, S. A.; Sommer, W. F.

    2001-07-01

    A number of candidate alloys were exposed to a particle flux and spectrum at Los Alamos Neutron Science Center (LANSCE) that closely match the mixed high-energy proton/neutron spectra expected in accelerator production of tritium (APT) window and blanket applications. Austenitic stainless steels 316 L and 304 L are two of these candidate alloys possessing attractive strength and corrosion resistance for APT applications. This paper describes the dose dependence of the irradiation-induced microstructural evolution of SS 316 L and 304 L in the temperature range 30-60°C and consequent changes in mechanical properties. It was observed that the microstructural evolution during irradiation was essentially identical in the two alloys, a behavior mirrored in their changes in mechanical properties. With one expection, it was possible to correlate all changes in mechanical properties with visible microstructural features. A late-term second abrupt decrease in uniform elongation was not associated with visible microstructure, but is postulated to be a consequence of large levels of retained hydrogen measured in the specimens. In spite of large amounts of both helium and hydrogen retained, approaching 1 at.% at the highest exposures, no visible cavities were formed, indicating that the gas atoms were either in solution or in subresolvable clusters.

  10. Effects of Ti-C:H coating and plasma nitriding treatment on tribological, electrochemical, and biocompatibility properties of AISI 316L.

    PubMed

    Kao, W H; Su, Y L; Horng, J H; Zhang, K X

    2016-08-01

    Ti-C:H coatings were deposited on original, nitrided, and polished-nitrided AISI 316L stainless steel substrates using a closed field unbalanced magnetron sputtering system. Sliding friction wear tests were performed in 0.89 wt.% NaCl solution under a load of 30 N against AISI 316L stainless steel, Si3N4, and Ti6Al4V balls, respectively. The electrochemical properties of the various specimens were investigated by means of corrosion tests performed in 0.89 wt.% NaCl solution at room temperature. Finally, the biocompatibility properties of the specimens were investigated by performing cell culturing experiments using purified mouse leukemic monocyte macrophage cells (Raw264.7). In general, the results showed that plasma nitriding followed by Ti-C:H coating deposition provides an effective means of improving the wear resistance, anti-corrosion properties, and biocompatibility performance of AISI 316L stainless steel. PMID:27422714

  11. Comparative study: sensitization development in hot-isostatic-pressed cast and wrought structures type 316L(N)-IG stainless steel under isothermal heat treatment

    NASA Astrophysics Data System (ADS)

    Shutko, K. I.; Belous, V. N.

    2002-12-01

    This work focuses on the relative sensitization resistance of type 316L(N)-IG stainless steel (SS). Cast and wrought structures SS after solid hot-isostatic pressing (solid-HIP) operation are investigated under isothermal heat treatment. Wrought SS/SS solid-HIP joint sensitization is taken also into consideration. These experiments employed the quantitative double-loop electrochemical potentiokinetic reactivation (DL-EPR) and oxalic acid etch screening tests. A copper-copper sulfate-16% sulfuric acid test applied for strongly sensitized cast SS to reinforce the results were received by the methods mentioned above. Results from all employed methods correlate well. Sensitization was detected neither in cast nor in wrought SS in as-HIPed condition excluding wrought SS/SS solid-HIP joints. Significant difference between sensitization development rates was determined in cast and wrought SS structures when annealing at 675 °C for a duration up to 50 h.

  12. On high-cycle fatigue of 316L stents.

    PubMed

    Barrera, Olga; Makradi, Ahmed; Abbadi, Mohammed; Azaouzi, Mohamed; Belouettar, Salim

    2014-01-01

    This paper deals with fatigue life prediction of 316L stainless steel cardiac stents. Stents are biomedical devices used to reopen narrowed vessels. Fatigue life is dominated by the cyclic loading due to the systolic and diastolic pressure and the design against premature mechanical failure is of extreme importance. Here, a life assessment approach based on the Dang Van high cycle fatigue criterion and on finite element analysis is applied to explore the fatigue reliability of 316L stents subjected to multiaxial fatigue loading. A finite element analysis of the stent vessel subjected to cyclic pressure is performed to carry out fluctuating stresses and strain at some critical elements of the stent where cracks or complete fracture may occur. The obtained results show that the loading path of the analysed stent subjected to a pulsatile load pressure is located in the safe region concerning infinite lifetime. PMID:22587434

  13. Recrystallization and Grain Growth of 316L Stainless Steel Wires

    NASA Astrophysics Data System (ADS)

    Zhao, Xiuyun; Liu, Yong; Wang, Yan; Feng, Ping; Tang, Huiping

    2014-07-01

    Recrystallization and grain growth behaviors of 316L stainless steel wires with a diameter of 12 µm were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy (TEM), and X-ray diffraction techniques. Heavily cold-drawn wires were isothermally held at temperatures from 1073 K to 1223 K (800 °C to 950 °C) for various holding times. Optical microscopy and TEM observations showed that recrystallization grains have irregular shape and that twins exist. The texture formed during drawing and annealing processes of the wires, as measured by X-ray methods, showed a fiber texture approximated by a <111> and a <100> component. The value of the grain growth exponent n was calculated, and the kinetic rates were plotted using the Arrhenius equation. Results show that the activation energy of the grain growth for 316L stainless steel wire was determined to be 407 kJ/mol, which was much higher than that of the bulk 316L stainless steel. The small wire diameter and the existence of texture played important roles in the increase of the activation energy for grain growth of the wire.

  14. Corrosion of type 316L stainless steel in a mercury thermal convection loop

    SciTech Connect

    DiStefano, J.R.; Manneschmidt, E.T.; Pawel, S.J.

    1999-04-01

    Two thermal convection loops fabricated from 316L stainless steel containing mercury (Hg) and Hg with 1000 wppm gallium (Ga), respectively, were operated continuously for about 5000 h. In each case, the maximum loop temperature was constant at about 305 degrees C and the minimum temperature was constant at about 242 degrees C. Coupons in the hot leg of the Hg-loop developed a posous surface layer substantially depleted of nickel and chromium, which resulted in a transformation to ferrite. The coupon exposed at the top of the hot leg in the Hg-loop experienced the maximum degradation, exhibiting a surface layer extending an average of 9-10 mu m after almost 5000 h. Analysis of the corrosion rate data as a function of temperature (position) in the Hg-loop suggests wetting by the mer cury occurred only above about 255 degrees C and that the rate limiting step in the corrosion process above 255 degrees C is solute diffusion through the saturated liquid boundary layer adjacent to the corroding surface. The latter factor suggests that the corrosion of 316L stainless steel in a mercury loop may be velocity dependent. No wetting and no corrosion were observed on the coupons and wall specimens removed from the Hg/Ga loop after 5000 h of operation.

  15. Reduced platelet adhesion and improved corrosion resistance of superhydrophobic TiO₂-nanotube-coated 316L stainless steel.

    PubMed

    Huang, Qiaoling; Yang, Yun; Hu, Ronggang; Lin, Changjian; Sun, Lan; Vogler, Erwin A

    2015-01-01

    Superhydrophilic and superhydrophobic TiO2 nanotube (TNT) arrays were fabricated on 316L stainless steel (SS) to improve corrosion resistance and hemocompatibility of SS. Vertically-aligned superhydrophilic amorphous TNTs were fabricated on SS by electrochemical anodization of Ti films deposited on SS. Calcination was carried out to induce anatase phase (superhydrophilic), and fluorosilanization was used to convert superhydrophilicity to superhydrophobicity. The morphology, structure and surface wettability of the samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and contact angle goniometry. The effects of surface wettability on corrosion resistance and platelet adhesion were investigated. The results showed that crystalline phase (anatase vs. amorphous) and wettability strongly affected corrosion resistance and platelet adhesion. The superhydrophilic amorphous TNTs failed to protect SS from corrosion whereas superhydrophobic amorphous TNTs slightly improved corrosion resistance of SS. Both superhydrophilic and superhydrophobic anatase TNTs significantly improved corrosion resistance of SS. The superhydrophilic amorphous TNTs minimized platelet adhesion and activation whereas superhydrophilic anatase TNTs activated the formation of fibrin network. On the contrary, both superhydrophobic TNTs (superhydrophobic amorphous TNTs and superhydrophobic anatase TNTs) reduced platelet adhesion significantly and improved corrosion resistance regardless of crystalline phase. Superhydrophobic anatase TNTs coating on SS surface offers the opportunity for the application of SS as a promising permanent biomaterial in blood contacting biomedical devices, where both reducing platelets adhesion/activation and improving corrosion resistance can be effectively combined. PMID:25481855

  16. The Effect of Constant and Pulsed Current Gas Tungsten Arc Welding on Joint Properties of 2205 Duplex Stainless Steel to 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Neissi, R.; Shamanian, M.; Hajihashemi, M.

    2016-05-01

    In this study, dissimilar 316L austenitic stainless steel/2205 duplex stainless steel (DSS) joints were fabricated by constant and pulsed current gas tungsten arc welding process using ER2209 DSS as a filler metal. Microstructures and joint properties were characterized using optical and electron scanning microscopy, tensile, Charpy V-notch impact and micro-hardness tests, and cyclic polarization measurements. Microstructural observations confirmed the presence of chromium nitride and delta ferrite in the heat-affected zone of DSS and 316L, respectively. In addition, there was some deviation in the austenite/ferrite ratio of the surface welding pass in comparison to the root welding pass. Besides having lower pitting potential, welded joints produced by constant current gas tungsten arc welding process, consisted of some brittle sigma phase precipitates, which resulted in some impact energy reduction. The tensile tests showed high tensile strength for the weld joints in which all the specimens were broken in 316L base metal.

  17. The Effect of Constant and Pulsed Current Gas Tungsten Arc Welding on Joint Properties of 2205 Duplex Stainless Steel to 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Neissi, R.; Shamanian, M.; Hajihashemi, M.

    2016-04-01

    In this study, dissimilar 316L austenitic stainless steel/2205 duplex stainless steel (DSS) joints were fabricated by constant and pulsed current gas tungsten arc welding process using ER2209 DSS as a filler metal. Microstructures and joint properties were characterized using optical and electron scanning microscopy, tensile, Charpy V-notch impact and micro-hardness tests, and cyclic polarization measurements. Microstructural observations confirmed the presence of chromium nitride and delta ferrite in the heat-affected zone of DSS and 316L, respectively. In addition, there was some deviation in the austenite/ferrite ratio of the surface welding pass in comparison to the root welding pass. Besides having lower pitting potential, welded joints produced by constant current gas tungsten arc welding process, consisted of some brittle sigma phase precipitates, which resulted in some impact energy reduction. The tensile tests showed high tensile strength for the weld joints in which all the specimens were broken in 316L base metal.

  18. Crack growth behavior of warm-rolled 316L austenitic stainless steel in high-temperature hydrogenated water

    NASA Astrophysics Data System (ADS)

    Choi, Kyoung Joon; Yoo, Seung Chang; Jin, Hyung-Ha; Kwon, Junhyun; Choi, Min-Jae; Hwang, Seong Sik; Kim, Ji Hyun

    2016-08-01

    To investigate the effects of warm rolling on the crack growth of 316L austenitic stainless steel, the crack growth rate was measured and the oxide structure was characterized in high-temperature hydrogenated water. The warm-rolled specimens showed a higher crack growth rate compared to the as-received specimens because the slip bands and dislocations produced during warm rolling served as paths for corrosion and cracking. The crack growth rate increased with the dissolved hydrogen concentration. This may be attributed to the decrease in performance and stability of the protective oxide layer formed on the surface of stainless steel in high-temperature water.

  19. Surface modification of investment cast-316L implants: microstructure effects.

    PubMed

    El-Hadad, Shimaa; Khalifa, Waleed; Nofal, Adel

    2015-03-01

    Artificial femur stem of 316L stainless steel was fabricated by investment casting using vacuum induction melting. Different surface treatments: mechanical polishing, thermal oxidation and immersion in alkaline solution were applied. Thicker hydroxyapatite (HAP) layer was formed in the furnace-oxidized samples as compared to the mechanically polished ones. The alkaline treatment enhanced the precipitation of HAP on the samples. It was also observed that the HAP precipitation responded differently to the different phases of the microstructure. The austenite phase was observed to have more homogeneous and smoother layer of HAP. In addition, the growth of HAP was sometimes favored on the austenite phase rather than on ferrite phase. PMID:25579929

  20. Effect of Starch Binders in Alumina Coatings on Aisi 316 L Stainless Steel for Medical Application

    NASA Astrophysics Data System (ADS)

    Ghazali, M. J.; Pauzi, A. A.; Azhari, C. H.; Ghani, J. A.; Sulong, A. B.; Mustafa, R.

    A slurry immersion technique of alumina coatings was carried out on several AISI 316 L stainless steels using two types of binding agents; commercial starch and Sarawakian starch (sago), which were also mixed with polyvinylchloride (PVA) for strengthening purposes. The sintering temperatures in this work were varied from 500 to 1000°C. Prior to sintering process, all stainless steels were metallographically ground and polished to approximately 0.6 µm of average roughness. Detailed characterisations on the sintered specimens were carried out with the aid of the secondary electron microscopy (SEM), microhardness and a profilometer. The results revealed that coated steels using sago binder showed improved adhesion and homogenous microstructures with greater hardness of 2642 HV than those found in coated steel with commercial starch after sintering process.

  1. Characterization of irradiated AISI 316L stainless steel disks removed from the Spallation Neutron Source

    SciTech Connect

    Vevera, Bradley J; Hyres, James W; McClintock, David A; Riemer, Bernie

    2014-01-01

    Irradiated AISI 316L stainless steel disks were removed from the Spallation Neutron Source (SNS) for post-irradiation examination (PIE) to assess mechanical property changes due to radiation damage and erosion of the target vessel. Topics reviewed include high-resolution photography of the disk specimens, cleaning to remove mercury (Hg) residue and surface oxides, profile mapping of cavitation pits using high frequency ultrasonic testing (UT), high-resolution surface replication, and machining of test specimens using wire electrical discharge machining (EDM), tensile testing, Rockwell Superficial hardness testing, Vickers microhardness testing, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The effectiveness of the cleaning procedure was evident in the pre- and post-cleaning photography and permitted accurate placement of the test specimens on the disks. Due to the limited amount of material available and the unique geometry of the disks, machine fixturing and test specimen design were critical aspects of this work. Multiple designs were considered and refined during mock-up test runs on unirradiated disks. The techniques used to successfully machine and test the various specimens will be presented along with a summary of important findings from the laboratory examinations.

  2. The influence of electropolishing on the corrosion resistance of 316L stainless steel.

    PubMed

    Sutow, E J

    1980-09-01

    A study was conducted which examined the influence of electropolishing on the corrosion resistance of a cold rolled 316L stainless steel. Test specimens were surface prepared to a final mechanical finish of wetted 600 grit SiC paper, prior to electropolishing. An o-H3PO4/Glycerol/H2O electropolishing solution was employed for times of 15, 20, and 25 min. Control specimens were surface prepared only to the final mechanical finish. Anodic polarization tests were performed in a deaerated Ringer's solution (37 degrees C) which was acidified to pH 1, with HCl. The electropolished specimens demonstrated increased corrosion resistance, when compared to the control specimens. This was evidenced for the former by more anodic corrosion and breakdown potentials, and the absence of a dissolution peak which was observed for the control specimens at the initial polarization potentials. Surface hardness measurements indicated that this increase in corrosion resistance was produced, in part, by the removal of the cold worked surface layer produced by the mechanical finish. In terms of increasing corrosion resistance, no optimum electropolishing time was found within the 15-25 min treatment period. PMID:7349665

  3. Electrochemical Corrosion and In Vitro Bioactivity of SiO2:ZrO2-Coated 316L Stainless Steel in Simulated Body Fluid

    NASA Astrophysics Data System (ADS)

    Srinivasan, A.; Rajendran, N.

    2015-08-01

    The effect of Si:Zr ratio on the in vitro bioactivity and electrochemical corrosion behavior of SiO2:ZrO2-mixed oxide-coated 316L stainless steel (SS) was evaluated in simulated body fluid (SBF) solution for 72, 120, and 168 h. Growth of Hydroxyapatite (HAp) was accelerated when Si content in the coating was increased. The Zr content in the coating improved the corrosion resistance of 316L SS rather than accelerating the HAp growth. When the Si:Zr ratio was 50:50, the coating exhibited significant improvement in corrosion resistance as well as HAp growth. The mechanism of HAp growth was proposed based on the change in surface zeta potential values of the coatings. Potentiodynamic polarization studies revealed about 10 and 5 times reduction in corrosion current density ( i corr) values for SiO2:ZrO2 (50:50)-coated 316L SS after 168 h of immersion compared to SiO2, ZrO2, and Si:Zr (70:30) coatings in SBF solutions thus confirming the superior corrosion resistance. The equivalent circuit parameters derived from electrochemical impedance spectroscopy studies further confirmed significant improvement in charge transfer resistance value even after 168 h of exposure.

  4. Fibrinogen adsorption onto 316L stainless steel, Nitinol and titanium

    NASA Astrophysics Data System (ADS)

    Bai, Zhijun; Filiaggi, M. J.; Dahn, J. R.

    2009-03-01

    Fibrinogen adsorption onto mechanically polished biomedical grade 316L stainless steel (316LSS), nickel titanium alloy (Nitinol) and commercially pure titanium (CpTi) surfaces were studied by measurements of adsorption isotherms and adsorption kinetics using an ex-situ wavelength dispersive spectroscopy technique (WDS). Surface composition, roughness and wettability of these materials were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and water contact angle (WCA) measurements. Adsorption isotherm results showed that surface protein concentration on these materials increased with increasing concentration of fibrinogen in phosphate buffer solution. The fibrinogen adsorption isotherms were modeled by both the monolayer Langmuir isotherm and the multilayer Brunauer-Emmett-Teller (BET) isotherm. The results strongly suggest that fibrinogen forms multilayer structures on these materials when the concentration in solution is high. Complementary measurements on the absorbed fibrinogen films by spectroscopic ellipsometry (SE) support this view.

  5. Comparative study of mechanical properties of 316L stainless steel between traditional production methods and selective laser melting

    NASA Astrophysics Data System (ADS)

    Lackey, Alton Dale

    Additive manufacturing, also known as 3D printing, is a technology which has recently seen expanding use, as well as expansion of the materials and methods able to be used. This thesis looks at the comparison of mechanical properties of 316L stainless steel manufactured by both traditional methods and selective laser melting found by tensile testing. The traditional method used here involved cold rolled 316L steel being machined to the desired part geometry. Selective laser melting used additive manufacturing to produce the parts from powdered 316L stainless steel, doing so in two different build orientations, flat and on edge with regards to the build plate. Solid test specimens, as well as specimens containing a circular stress concentration in the center of the parts, were manufactured and tensile tested. The tensile tests of the specimens were used to find the mechanical properties of the material; including yield strength, ultimate tensile strength (UTS), and Young's modulus of elasticity; where statistical analyses were performed to determine if the different manufacturing processes caused significant differences in the mechanical properties of the material. These analysis consisting of f-tests, to test for variance, and t-test, testing for significant difference of means. Through this study it was found that there were statistically significant differences existing between the mechanical properties of selective laser melting, and its orientations, and cold roll forming of production of parts. Even with a statistical difference, it was found that the results were reasonably close between flat oriented SLM parts and purchased parts. So it can be concluded that, with regards to strength, SLM methods produce parts similar to traditional production methods.

  6. A study of Ta xC 1 -x coatings deposited on biomedical 316L stainless steel by radio-frequency magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ding, M. H.; Wang, B. L.; Li, L.; Zheng, Y. F.

    2010-11-01

    In this paper, Ta xC 1 -x coatings were deposited on 316L stainless steel (316L SS) by radio-frequency (RF) magnetron sputtering at various substrate temperatures ( Ts) in order to improve its corrosion resistance and hemocompatibility. XRD results indicated that Ts could significantly change the microstructure of Ta xC 1 -x coatings. When Ts was <150 °C, the Ta xC 1 -x coatings were in amorphous condition, whereas when Ts was ≥150 °C, TaC phase was formed, exhibiting in the form of particulates with the crystallite sizes of about 15-25 nm ( Ts = 300 °C). Atomic force microscope (AFM) results showed that with the increase of Ts, the root-mean-square (RMS) values of the Ta xC 1 -x coatings decreased. The nano-indentation experiments indicated that the Ta xC 1 -x coating deposited at 300 °C had a higher hardness and modulus. The scratch test results demonstrated that Ta xC 1 -x coatings deposited above 150 °C exhibited good adhesion performance. Tribology tests results demonstrated that Ta xC 1 -x coatings exhibited excellent wear resistance. The results of potentiodynamic polarization showed that the corrosion resistance of the 316L SS was improved significantly because of the deposited Ta xC 1 -x coatings. The platelet adhesion test results indicated that the Ta xC 1 -x coatings deposited at Ts of 150 °C and 300 °C possessed better hemocompatibility than the coating deposited at Ts of 25 °C. Additionally, the hemocompatibility of the Ta xC 1 -x coating on the 316L SS was found to be influenced by its surface roughness, hydrophilicity and the surface energy.

  7. Multilayered Zr-C/a-C film on stainless steel 316L as bipolar plates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Bi, Feifei; Peng, Linfa; Yi, Peiyun; Lai, Xinmin

    2016-05-01

    A multilayered zirconium-carbon/amorphous carbon (Zr-C/a-C) coating is synthesized by magnetron sputtering in order to improve the corrosion resistance and interfacial conductivity of stainless steel 316L (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). Zr-C/a-C film contains an outmost pure amorphous carbon layer and a sub zirconium containing carbon layer. Interfacial contact resistance (ICR) between carbon paper and coated SS316L decreases to 3.63 mΩ cm2 at 1.4 MPa. Potentiodynamic polarization results reveal that the corrosion potential of Zr-C/a-C coated sample is more positive than pure a-C coated sample and the current density is only 0.49 μA cm-2 at the cathode applied potential 0.6 V. Electrochemical impendence spectroscopy also indicates that multilayered Zr-C/a-C film coated SS316L has much higher charge transfer resistance than the bare sample. After potentiostatic polarization, ICR values are 3.92 mΩ cm2 and 3.82 mΩ cm2 in the simulated PEMFCs cathode and anode environment, respectively. Moreover, XPS analysis of the coated samples before and after potential holding tests shows little difference, which disclose the chemical stability of multilayered Zr-C/a-C film. Therefore, the multilayered Zr-C/a-C coating exhibits excellent performance in various aspects and is preferred for the application of stainless steel bipolar plates.

  8. Dynamic Mechanical Response of Biomedical 316L Stainless Steel as Function of Strain Rate and Temperature

    PubMed Central

    Lee, Woei-Shyan; Chen, Tao-Hsing; Lin, Chi-Feng; Luo, Wen-Zhen

    2011-01-01

    A split Hopkinson pressure bar is used to investigate the dynamic mechanical properties of biomedical 316L stainless steel under strain rates ranging from 1 × 103 s−1 to 5 × 103 s−1 and temperatures between 25°C and 800°C. The results indicate that the flow stress, work-hardening rate, strain rate sensitivity, and thermal activation energy are all significantly dependent on the strain, strain rate, and temperature. For a constant temperature, the flow stress, work-hardening rate, and strain rate sensitivity increase with increasing strain rate, while the thermal activation energy decreases. Catastrophic failure occurs only for the specimens deformed at a strain rate of 5 × 103 s−1 and temperatures of 25°C or 200°C. Scanning electron microscopy observations show that the specimens fracture in a ductile shear mode. Optical microscopy analyses reveal that the number of slip bands within the grains increases with an increasing strain rate. Moreover, a dynamic recrystallisation of the deformed microstructure is observed in the specimens tested at the highest temperature of 800°C. PMID:22216015

  9. An in vitro investigation of the anodic polarization and capacitance behavior of 316-L stainless steel.

    PubMed

    Sutow, E J; Pollack, S R; Korostoff, E

    1976-09-01

    Determinations were made of how the corrosion-resistant properties of the passive film on 316-L stainless steel are influenced by the material's mechanical and surface states, and the variable pH and PO2 conditions of the interstitial fluid. Cold-rolled and annealed specimens were surface-prepared, commercially and in the laboratory, respectively, as if for orthopedic implantation. Passive film behavior was studied by the anodic polarization and pulse-potentiostatic capacitance methods. The pH and PO2 of the Ringer's test solution were varied to include interstitial fluid values occurring postoperatively and onto recovery. The anodic polarization behavior of all specimens was found to be pH- and PO2-independent. Breakdown potentials of annealed specimens were 800-950 mV (SCE), in contrast to previously reported values of approximately 350 mV. This substantial increase is related to the influence of surface preparation and, in particular, to the optimization of electropolishing time which acts to produce a microscopically smooth surface, free of debris and disarrayed material. Capacitance behavior of annealed material for potentials greater than 400 mV was consistent with a model involving the entry of chloride and metal ions (mostly Fe) into the passive film. This entry is related to the onset of pitting. PMID:10307

  10. Reduced graphene oxide growth on 316L stainless steel for medical applications

    NASA Astrophysics Data System (ADS)

    Cardenas, L.; MacLeod, J.; Lipton-Duffin, J.; Seifu, D. G.; Popescu, F.; Siaj, M.; Mantovani, D.; Rosei, F.

    2014-07-01

    We report a new method for the growth of reduced graphene oxide (rGO) on the 316L alloy of stainless steel (SS) and its relevance for biomedical applications. We demonstrate that electrochemical etching increases the concentration of metallic species on the surface and enables the growth of rGO. This result is supported through a combination of Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), density functional theory (DFT) calculations and static water contact angle measurements. Raman spectroscopy identifies the G and D bands for oxidized species of graphene at 1595 cm-1 and 1350 cm-1, respectively, and gives an ID/IG ratio of 1.2, indicating a moderate degree of oxidation. XPS shows -OH and -COOH groups in the rGO stoichiometry and static contact angle measurements confirm the wettability of rGO. SEM and AFM measurements were performed on different substrates before and after coronene treatment to confirm rGO growth. Cell viability studies reveal that these rGO coatings do not have toxic effects on mammalian cells, making this material suitable for biomedical and biotechnological applications.

  11. Effect of laser shot peening without coating on the surface properties and corrosion behavior of 316L steel

    NASA Astrophysics Data System (ADS)

    Kalainathan, S.; Sathyajith, S.; Swaroop, S.

    2012-12-01

    This paper discusses the results of laser peening without coating on low carbon austenitic stainless steel 316L. Unlike typical experiments on laser peening without coating (LPwC) performed with frequency doubled (green) laser and underwater irradiation, the present study reports LPwC with infrared radiation using thin layer of water as confinement medium. The dependence of laser pulse density on properties such as surface roughness, surface residual stress, microhardness, and corrosion behavior of LPwC specimen were investigated. The magnitude of surface compressive residual stress on laser peened specimen showed appreciable improvement compared to unpeened base material. Microhardness of the specimen improved by 30-40% after LPwC. However, the potentiodynamic polarization study indicated that though there is an enhancement of corrosion potential (Ecorr), the corrosion current density (Icorr) increased with increase in laser pulse density.

  12. Rapid heating tensile tests of high-energy-rate-forged 316L stainless steel containing internal helium from radioactive decay of absorbed tritium

    SciTech Connect

    Mosley, W.C.

    1990-01-01

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. This austenitic stainless steel is frequently used in the high-energy-rate-forged (HERF) metallurgical condition to take advantage of increased strength produced by cold work introduced by this process. Proper design of tritium-handling equipment will require an understanding of how helium-3, the product of radioactive decay of tritium, affects mechanical properties. This report describes results of elevated-temperature tensile testing of HERF 316L stainless steel specimens containing helium concentrations of 171 (calculated) atomic parts per million (appm). Results are compared with those reported previously for specimens containing 0 and 94 (measured) appm helium.

  13. Rapid heating tensile tests of high-energy-rate-forged 316L stainless steel containing internal helium from radioactive decay of absorbed tritium

    SciTech Connect

    Mosley, W.C.

    1990-12-31

    316L stainless steel is a candidate material for construction of equipment that will be exposed to tritium. This austenitic stainless steel is frequently used in the high-energy-rate-forged (HERF) metallurgical condition to take advantage of increased strength produced by cold work introduced by this process. Proper design of tritium-handling equipment will require an understanding of how helium-3, the product of radioactive decay of tritium, affects mechanical properties. This report describes results of elevated-temperature tensile testing of HERF 316L stainless steel specimens containing helium concentrations of 171 (calculated) atomic parts per million (appm). Results are compared with those reported previously for specimens containing 0 and 94 (measured) appm helium.

  14. On the fate of tritium in thermally treated stainless steel type 316L

    NASA Astrophysics Data System (ADS)

    Penzhorn, R.-D.; Torikai, Y.; Watanabe, K.; Matsuyama, M.; Perevezentsev, A.

    2012-10-01

    Several type 316L stainless steel specimens of 6 mm thickness were charged with tritium at 473 K at Joint European Torus (JET) using five sets of conditions. Isothermal tritium release rates were investigated at Hydrogen Isotope Research Centre (HRC) over extended periods of time at 473, 573, or 673 K constant temperature. The HTO/HT ratio of the liberated tritium was generally high, but decreased with decreasing release temperature. Nearly complete release of tritium required additional prolonged heating at 1073 K. Chemical etching and beta-ray-induced X-ray spectrometry measurements carried out at HRC provided complementary information on the tritium distribution in surface and bulk of thermally treated specimens. Whereas the thickness of the material and initial distribution of tritium in its bulk were found to play an important role for expedient thermal decontamination, the influence of the type of purge gas was only minor. Experimental evidence for tritium grain boundary diffusion is provided. Implications of the results for waste conditioning are discussed.

  15. Improving the corrosion wear resistance of AISI 316L stainless steel by particulate reinforced Ni matrix composite alloying layer

    NASA Astrophysics Data System (ADS)

    Xu, Jiang; Zhuo, Chengzhi; Tao, Jie; Jiang, Shuyun; Liu, Linlin

    2009-01-01

    In order to overcome the problem of corrosion wear of AISI 316L stainless steel (SS), two kinds of composite alloying layers were prepared by a duplex treatment, consisting of Ni/nano-SiC and Ni/nano-SiO2 predeposited by brush plating, respectively, and subsequent surface alloying with Ni-Cr-Mo-Cu by a double glow process. The microstructure of the two kinds of nanoparticle reinforced Ni-based composite alloying layers was investigated by means of SEM and TEM. The electrochemical corrosion behaviour of composite alloying layers compared with the Ni-based alloying layer and 316L SS under different conditions was characterized by potentiodynamic polarization test and electrochemical impedance spectroscopy. Results showed that under alloying temperature (1000 °C) conditions, amorphous nano-SiO2 particles still retained the amorphous structure, whereas nano-SiC particles were decomposed and Ni, Cr reacted with SiC to form Cr6.5Ni2.5Si and Cr23C6. In static acidic solution, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is lower than that of the Ni-based alloying layer. However, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is prominently superior to that of the Ni-based alloying layer under acidic flow medium condition and acidic slurry flow condition. The corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiC particles interlayer is evidently lower than that of the Ni-based alloying layer, but higher than that of 316L SS under all test conditions. The results show that the highly dispersive nano-SiO2 particles are helpful in improving the corrosion wear resistance of the Ni-based alloying layer, whereas carbides and silicide phase are deleterious to that of the Ni-based alloying layer due to the fact that the preferential removal of the matrix around the precipitated phase takes place by the chemical

  16. High-Temperature Oxidation Resistance of a Nanoceria Spray-Coated 316L Stainless Steel Under Short-Term Air Exposure

    NASA Astrophysics Data System (ADS)

    Lopez, Hugo F.; Mendoza, Humberto; Church, Ben

    2013-10-01

    Nanoceria coatings using a spray method were implemented on a 316L stainless steel (SS). Coated and uncoated coupons were exposed to dry air at 1073 K to 1273 K (800 °C to 1000 °C) for short time periods (up to 24 hours) and in situ measurements of oxidation were carried out using a highly sensitive thermogravimetric balance. From the experimental outcome, activation energies were determined in both, coated and uncoated 316 SS coupons. The estimated exhibited activation energies for oxidation in the coated and uncoated conditions were 174 and 356 kJ/mol, respectively. In addition, the developed scales were significantly different. In the coated steel, the dominant oxide was an oxide spinel (Fe, Mn)3O4 and the presence of Fe2O3 was sharply reduced, particularly at 1273 K (1000 °C). In contrast, no spinel was found in the uncoated 316L SS, and Fe2O3 was always present in the scale at all the investigated oxidation temperatures. The coated steels developed a highly adherent fine-grained scale structure. Apparently, the nanoceria particles enhanced nucleation of the newly formed scale while restricting coarsening. Coarse grain structures were found in the uncoated steels with scale growth occurring at grain ledges. Moreover, the oxidation rates for the coated 316L SS were at least an order of magnitude lower than those exhibited by the steel in the uncoated condition. The reduction in oxidation rates is attributed to a shift in the oxidation mechanism from outward cation diffusion to inward oxygen diffusion.

  17. Effect of bicarbonate ion additives on pitting corrosion of type 316L stainless steel in aqueous 0.5 M sodium chloride solution

    SciTech Connect

    Park, J.J.; Pyun, S.I.; Lee, W.J.; Kim, H.P.

    1999-04-01

    The effect of bicarbonate ions (HCO{sub 3}{sup {minus}}) on pitting corrosion of type 316L stainless steel (SS, UNS S3 1603) was investigated in aqueous 0.5 M sodium chloride (NaCl) solution using potentiodynamic polarization, the abrading electrode technique, alternating current (AC) impedance spectroscopy combined with x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Addition of HCO{sub 3}{sup {minus}} ions to NaCl solutions extended the passive potential region in width and, at the same time, raised the pitting potential in value on the potentiodynamic polarization curve. Potentiostatic current transients obtained from the moment just after interrupting the abrading action showed the repassivation rate of propagating pits increased and that the pit growth rate decreased with increasing HCO{sub 3}{sup {minus}} ion concentration. Over the whole applied potential, the oxide film resistance was higher in the presence of HCO{sub 3}{sup {minus}} ions. The pit number density decreased with increasing HCO{sub 3}{sup {minus}} ion concentration. Moreover, addition of HCO{sub 3}{sup {minus}} ions to NaCl solutions retarded lateral pit growth, while promoting downward pit growth from the surface. The bare surface of the specimen repassivated preferentially along the pit mouth and walls, compared to the pit bottom, as a result of formation of a surface film with a high content of protective mixed ferrous-chromous carbonate ([Fe,Cr]CO{sub 3}) that formed from preferential adsorption of HCO{sub 3}{sup {minus}} ions.

  18. Helium effects on the post-implantation creep properties and the microstructure of AISI 316L welds and parent material

    NASA Astrophysics Data System (ADS)

    Dai, Yong; Schroeder, Herbert

    1992-09-01

    The influence of implanted helium on the creep properties in electron-beam welds of the Next European Torus (NET) reference material, AISI 316L, and its parent material in the as-received condition has been investigated at 873 K. Helium degredation effects (i.e. reduced creep rupture time and creep rupture strain) are more serious in the parent material than in the welds. The fracture mode for implanted weld specimens is usually transgranular, while for the parent material specimens it is mixed trans- and intergranular. TEM investigations show that in the welds there is a lot of σ-ferrite at grain boundaries (occupying about 50% of grain boundary area) and in the interior of grains as well. Helium bubble sizes increase with increasing helium concentration, while helium bubble densities remain constant. Helium bubbles in the matrix are larger in size but much lower in density than those at boundaries or interfaces.

  19. Microstructural aspects of creep-rupture life of Type 316L(N) stainless steel in liquid sodium environment

    NASA Astrophysics Data System (ADS)

    Mishra, M. P.; Borgstedt, H. U.; Frees, G.; Seith, B.; Mannan, S. L.; Rodriguez, P.

    1993-04-01

    The influence of flowing sodium on creep-rupture properties of AISI Type 316L(N) stainless steel base material has been investigated at 550 and 600°C. In sodium test results were compared with reference creep-rupture data generated in air. The creep-rupture lives were longer in air than in sodium environment at 550°C, however, at 600°C, creep-rupture lives were longer in the latter than in the former environment. Microstructural studies showed the presence of sensitization and χ phase on longer duration test specimens at both temperatures. Surface cracks in sodium tested specimens were sharp and relatively more in numbers than in air where cracks were blunted. Cracks seem to follow the intergranular mode. Cavities were formed in long duration tests and propagated ahead of the χ phase.

  20. Corrosion Resistance of Powder Metallurgy Processed TiC/316L Composites with Mo Additions

    NASA Astrophysics Data System (ADS)

    Lin, Shaojiang; Xiong, Weihao

    2015-06-01

    To find out the effects of Mo addition on corrosion resistance of TiC/316L stainless steel composites, TiC/316L composites with addition of different contents of Mo were prepared by powder metallurgy. The corrosion resistance of these composites was evaluated by the immersion tests and polarization curves experiments. Results indicated that Mo addition decreased the corrosion rates of TiC/316L composites in H2SO4 solution in the case of Mo content below 2% whereas it displayed an opposite effect when Mo content was above that value. It was found that with an increase in the Mo content, the pitting corrosion resistance increased monotonically for TiC/316L composites in NaCl solution.

  1. Microbiological test results using three urine pretreatment regimes with 316L stainless steel

    NASA Technical Reports Server (NTRS)

    Huff, Timothy L.

    1993-01-01

    Three urine pretreatments, (1) Oxone (Dupont) and sulfuric acid, (2) sodium hypochlorite and sulfuric acid, (3) and ozone, were studied for their ability to reduce microbial levels in urine and minimize surface attachment to 316L stainless steel coupons. Urine samples inoculated with Bacillus insolitus and a filamentous mold, organisms previously recovered from the vapor compression distillation subsystem of NASA Space Station Freedom water recovery test were tested in glass corrosion cells containing base or weld metal coupons. Microbial levels, changes in pH, color, turbidity, and odor of the fluid were monitored over the course of the 21-day test. Specimen surfaces were examined by scanning electron microscopy at completion of the test for microbial attachment. Ozonated urine samples were less turbid and had lower microbial levels than controls or samples receiving other pretreatments. Base metal coupons receiving pretreatment were relatively free of attached bacteria. However, well-developed biofilms were found in the heat-affected regions of welded coupons receiving Oxone and hypochlorite pretreatments. Few bacteria were observed in the same regions of the ozone pretreatment sample.

  2. A New Vacuum Brazing Route for Niobium-316L Stainless Steel Transition Joints for Superconducting RF Cavities

    NASA Astrophysics Data System (ADS)

    Kumar, Abhay; Ganesh, P.; Kaul, R.; Bhatnagar, V. K.; Yedle, K.; Ram Sankar, P.; Sindal, B. K.; Kumar, K. V. A. N. P. S.; Singh, M. K.; Rai, S. K.; Bose, A.; Veerbhadraiah, T.; Ramteke, S.; Sridhar, R.; Mundra, G.; Joshi, S. C.; Kukreja, L. M.

    2015-02-01

    The paper describes a new approach for vacuum brazing of niobium-316L stainless steel transition joints for application in superconducting radiofrequency cavities. The study exploited good wettability of titanium-activated silver-base brazing alloy (CuSil-ABA®), along with nickel as a diffusion barrier, to suppress brittle Fe-Nb intermetallic formation, which is well reported during the established vacuum brazing practice using pure copper filler. The brazed specimens displayed no brittle intermetallic layers on any of its interfaces, but instead carried well-distributed intermetallic particles in the ductile matrix. The transition joints displayed room temperature tensile and shear strengths of 122-143 MPa and 80-113 MPa, respectively. The joints not only exhibited required hermeticity (helium leak rate <1.1 × 10-10 mbar l/s) for service in ultra-high vacuum but also withstood twelve hour degassing heat treatment at 873 K (suppresses Q-disease in niobium cavities), without any noticeable degradation in the microstructure and the hermeticity. The joints retained their leak tightness even after undergoing ten thermal cycles between the room temperature and the liquid nitrogen temperature, thereby establishing their ability to withstand service-induced low cycle fatigue conditions. The study proposes a new lower temperature brazing route to form niobium-316L stainless steel transition joints, with improved microstructural characteristics and acceptable hermeticity and mechanical properties.

  3. Tensile Stress-Strain Results for 304L and 316L Stainless-Steel Plate at Temperature

    SciTech Connect

    R. K. Blandford; D. K. Morton; S. D. Snow; T. E. Rahl

    2007-07-01

    The Idaho National Laboratory (INL) is conducting moderate strain rate (10 to 200 per second) research on stainless steel materials in support of the Department of Energy’s (DOE) National Spent Nuclear Fuel Program (NSNFP). For this research, strain rate effects are characterized by comparison to quasi-static tensile test results. Considerable tensile testing has been conducted resulting in the generation of a large amount of basic material data expressed as engineering and true stress-strain curves. The purpose of this paper is to present the results of quasi-static tensile testing of 304/304L and 316/316L stainless steels in order to add to the existing data pool for these materials and make the data more readily available to other researchers, engineers, and interested parties. Standard tensile testing of round specimens in accordance with ASTM procedure A 370-03a were conducted on 304L and 316L stainless-steel plate materials at temperatures ranging from -20 °F to 600 °F. Two plate thicknesses, eight material heats, and both base and weld metal were tested. Material yield strength, Young’s modulus, ultimate strength, ultimate strain, failure strength and failure strain were determined, engineering and true stress-strain curves to failure were developed, and comparisons to ASME Code minimums were made. The procedures used during testing and the typical results obtained are described in this paper.

  4. Electrochemical properties of 316L stainless steel with culturing L929 fibroblasts.

    PubMed

    Hiromoto, Sachiko; Hanawa, Takao

    2006-08-22

    Potentiodynamic polarization and impedance tests were carried out on 316L stainless steel with culturing murine fibroblast L929 cells to elucidate the corrosion behaviour of 316L steel with L929 cells and to understand the electrochemical interface between 316L steel and cells, respectively. Potential step test was carried out on 316L steel with type I collagen coating and culturing L929 cells to compare the effects of collagen and L929 cells. The open-circuit potential of 316L steel slightly shifted in a negative manner and passive current density increased with cells, indicating a decrease in the protective ability of passive oxide film. The pitting potential decreased with cells, indicating a decrease in the pitting corrosion resistance. In addition, a decrease in diffusivity at the interface was indicated from the decrease in the cathodic current density and the increase in the diffusion resistance parameter in the impedance test. The anodic peak current in the potential step test decreased with cells and collagen. Consequently, the corrosion resistance of 316L steel decreases with L929 cells. In addition, collagen coating would provide an environment for anodic reaction similar to that with culturing cells. PMID:16849246

  5. Influence of cold plastic deformation on critical pitting potential of AISI 316 L and 304 L steels in an artificial physiological solution simulating the aggressiveness of the human body.

    PubMed

    Cigada, A; Mazza, B; Pedeferri, P; Sinigaglia, D

    1977-07-01

    The effect of cold working on critical pitting potential of AISI 316 L and 304 L steels in a buffered physiological solution has been studied. In particular, the importance of deformation degree, orientation of the specimen surface to the deformation direction, and cold working temperature in lowering the critical pitting potential is shown. PMID:873942

  6. In-vitro bioactivity, biocorrosion and antibacterial activity of silicon integrated hydroxyapatite/chitosan composite coating on 316 L stainless steel implants.

    PubMed

    Sutha, S; Kavitha, K; Karunakaran, G; Rajendran, V

    2013-10-01

    A simple and effective ultrasonication method was applied for the preparation of 0, 0.4, 0.8, 1.0 and 1.6 wt% silicon substituted hydroxyapatite (HAp) (SH). The Ca/P ratio of the synthesised SH nanoparticles were in the range of 1.58-1.70. Morphological changes were noticed in HAp with respect to the amount of Si from 0 to 1.6 wt%. The morphology of the particles changed from spherical shape to rod-like morphology with respect to the amount of Si which was confirmed using transmission electron microscopy. X-ray diffraction studies confirm the formation of phase pure SH nanoparticles without any secondary phase. Chitosan (CTS) blended SH nanocomposites coating on surgical grade 316 L stainless steel (316 L SS) implant was made by spin coating technique. The surface of the coated implant was characterised using scanning electron microscopy which confirms the uniform coating without cracks and pores. The increased corrosion resistance of the 1.6 wt% of SH/CTS-coated SS implant in the simulated body fluid (SBF) indicates the long-term biostability of SH composite-coated ceramics in vitro than the 0 wt% SH/CTS. The testing of SH/CTS nanocomposites with gram-positive and gram-negative bacterial strains confirms that the antibacterial ability improves with the higher substitution of Si. In addition, formation of bone-like apatite layer on the SH/CTS-coated implant in SBF was studied through SEM analysis and it confirms the ability to increase the HAp formation on the surface of 1.0 wt% SH/CTS-coated 316 L SS implant. PMID:23910313

  7. Electrochemical behavior of nanocrystalline Ta/TaN multilayer on 316L stainless steel: Novel bipolar plates for proton exchange membrane fuel-cells

    NASA Astrophysics Data System (ADS)

    Alishahi, M.; Mahboubi, F.; Mousavi Khoie, S. M.; Aparicio, M.; Hübner, R.; Soldera, F.; Gago, R.

    2016-08-01

    Insufficient corrosion resistance and surface conductivity are two main issues that plague large-scale application of stainless steel (SS) bipolar plates in proton exchange membrane fuel cells (PEMFCs). This study explores the use of nanocrystalline Ta/TaN multilayer coatings to improve the electrical and electrochemical performance of polished 316L SS bipolar plates. The multilayer coatings have been deposited by (reactive) magnetron sputtering and characterized by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy. The electrochemical behavior of bare and coated substrates has been evaluated in simulated PEMFC working environments by potentiodynamic and potentiostatic polarization tests at ambient temperature and 80 °C. The results show that the Ta/TaN multilayer coating increases the polarization resistance of 316L SS by about 30 and 104 times at ambient and elevated temperatures, respectively. The interfacial contact resistance (ICR) shows a low value of 12 mΩ × cm2 before the potentiostatic test. This ICR is significantly lower than for the bare substrate and remains mostly unchanged after potentiostatic polarization for 14 h. In addition, the high contact angle (92°) with water for coated substrates indicates a hydrophobic character, which can improve the water management within the cell in PEMFC stacks.

  8. Influence of flowing sodium on creep deformation and rupture behaviour of 316L(N) austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Laha, K.; Mathew, M. D.; Vijayaraghavan, S.; Shanmugavel, M.; Rajan, K. K.; Jayakumar, T.

    2012-08-01

    The influence of flowing sodium on creep deformation and rupture behaviour of AISI 316L(N) austenitic stainless steel has been investigated at 873 K over a stress range of 235-305 MPa. The results were compared with those obtained from testing in air environment. The steady state creep rates of the material were not influenced appreciably by the testing environments. The time to onset of tertiary stage of creep deformation was delayed in sodium environment. The creep-rupture lives of the material increased in sodium environment, which became more pronounced at lower applied stresses. The increase in rupture life of the material in flowing sodium was accompanied by an increase in rupture ductility. The creep damage on specimen surface as well as inside the specimen was less in specimen tested in sodium. SEM fractographic investigation revealed predominantly transgranular dimple failure for the specimen tested in sodium, whereas predominantly intergranular creep failure was observed in the air tested specimens. Almost no oxidation was observed in the specimens creep tested in the sodium environment. Absence of oxidation and less creep damage cavitation extended the secondary state in liquid sodium tests and lead to increase in creep rupture life and ductility of the material as compared to in air.

  9. Effect of Heat Treatment on the Microstructure and Mechanical Properties of Stainless Steel 316L Coatings Produced by Cold Spray for Biomedical Applications

    NASA Astrophysics Data System (ADS)

    AL-Mangour, Bandar; Vo, Phuong; Mongrain, Rosaire; Irissou, Eric; Yue, Stephen

    2014-04-01

    In this study, the effects of heat treatment on the microstructure and mechanical properties of cold sprayed stainless steel 316L coatings using N2 and He as propellant gases were investigated. Powder and coating characterizations, including coating microhardness, coating porosity, and XRD phase analysis were performed. It was found that heat treatment reduced porosity, improved inter-particle bonding, and increased ductility. XRD results confirmed that no phase transformation occurred during deposition. Significant increase in UTS and ductility was observed for the annealed specimens obtained with nitrogen propellant, whereas little changes were observed for the helium propellant produced specimen.

  10. Performance Optimization of Cold Rolled Type 316L Stainless Steel by Sand Blasting and Surface Linishing Treatment

    NASA Astrophysics Data System (ADS)

    Krawczyk, B.; Heine, B.; Engelberg, D. L.

    2016-03-01

    Sand blasting followed by a surface linishing treatment was applied to optimize the near-surface microstructure of cold rolled type 316L stainless steel. The introduction of cold rolling led to the formation of α-martensite. Specimens with large thickness reductions (40, 53%) were more susceptible to localized corrosion. The application of sand blasting produced a near-surface deformation layer containing compressive residual stresses with significantly increased surface roughness, resulting in reduced corrosion resistance. The most resistant microstructure was obtained with the application of a final linishing treatment after sand blasting. This treatment produced microstructures with compressive near-surface residual stresses, reduced surface roughness, and increased resistance to localized corrosion.

  11. Preparation of uniform TiO 2 nanostructure film on 316L stainless steel by sol-gel dip coating

    NASA Astrophysics Data System (ADS)

    Barati, N.; Sani, M. A. Faghihi; Ghasemi, H.; Sadeghian, Z.; Mirhoseini, S. M. M.

    2009-07-01

    Sol was prepared by the mixing of tetra-η-butyle titanat, ethyl aceto acetate, and ethanol in an optimized condition. Polished 316L specimens were coated with the sol by dip-coating method. The influences of drying condition, withdrawal speed, calcination temperature, addition of dispersant, and pH of sol on TiO 2 nanostructure coating were investigated. Choosing of alcohol as drying atmosphere hindered the crack formation. The relation between coating thickness and withdrawal speed was evaluated. The optimum temperature to create a uniform distribution of nanoparticles of anatase was derived as 400 °C. Average roughness of coating was found about 10.61 nm by AFM analysis. Dispersant addition promoted formation of a uniform film as well as prevention of agglomeration. Acidic sol provided smaller particles than neutral sol.

  12. Influence of Sigma Phase on Pitting Resistance Depending on Solidification Mode in AISI316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Jang, A. Y.; Lee, H. W.

    2012-06-01

    The pitting corrosion resistances were investigated in the AISI 316L stainless steel weld metals with respect to the sigma phase precipitation in a 0.1 M NaCl solution. The modified flux-cored arc welding filler wires were fabricated at various chromium and nickel equivalent ratios using the flux-cored arc welding process. As the Cr/Ni equivalent ratio increased, the precipitated σ phase content increased in the temperature range of 923 K to 1123 K (650 °C to 850 °C), and the specimen that was aged at 1123 K (850 °C) precipitated the σ phase rapidly. The hardness increased with increasing sigma contents. During the potentiodynamic anodic polarization test, the specimens that were aged at 923 K to 1123 K (650 °C to 850 °C) exhibited lower pitting potentials than the as-weld metal. Additionally, the specimens that were aged for longer times exhibited lower pitting potentials. The pits occurred preferentially in the ductility dip cracking in specimen 1, whereas intergranular pits occurred in the sigma phase regions along the vermicular ferrite and acicular ferrite grain boundaries in specimens 2 and 3.

  13. Sliding Wear Characteristics and Corrosion Behaviour of Selective Laser Melted 316L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Moroz, A.; Alrbaey, K.

    2013-11-01

    Stainless steel is one of the most popular materials used for selective laser melting (SLM) processing to produce nearly fully dense components from 3D CAD models. The tribological and corrosion properties of stainless steel components are important in many engineering applications. In this work, the wear behaviour of SLM 316L stainless steel was investigated under dry sliding conditions, and the corrosion properties were measured electrochemically in a chloride containing solution. The results show that as compared to the standard bulk 316L steel, the SLM 316L steel exhibits deteriorated dry sliding wear resistance. The wear rate of SLM steel is dependent on the vol.% porosity in the steel and by obtaining full density it is possible achieve wear resistance similar to that of the standard bulk 316L steel. In the tested chloride containing solution, the general corrosion behaviour of the SLM steel is similar to that of the standard bulk 316L steel, but the SLM steel suffers from a reduced breakdown potential and is more susceptible to pitting corrosion. Efforts have been made to correlate the obtained results with porosity in the SLM steel.

  14. Highly porous, low elastic modulus 316L stainless steel scaffold prepared by selective laser melting.

    PubMed

    Čapek, Jaroslav; Machová, Markéta; Fousová, Michaela; Kubásek, Jiří; Vojtěch, Dalibor; Fojt, Jaroslav; Jablonská, Eva; Lipov, Jan; Ruml, Tomáš

    2016-12-01

    Recently, porous metallic materials have been extensively studied as candidates for use in the fabrication of scaffolds and augmentations to repair trabecular bone defects, e.g. in surroundings of joint replacements. Fabricating these complex structures by using common approaches (e.g., casting and machining) is very challenging. Therefore, rapid prototyping techniques, such as selective laser melting (SLM), have been investigated for these applications. In this study, we characterized a highly porous (87 vol.%) 316L stainless steel scaffold prepared by SLM. 316L steel was chosen because it presents a biomaterial still widely used for fabrication of joint replacements and, from the practical point of view, use of the same material for fabrication of an augmentation and a joint replacement is beneficial for corrosion prevention. The results are compared to the reported properties of two representative nonporous 316L stainless steels prepared either by SLM or casting and subsequent hot forging. The microstructural and mechanical properties and the surface chemical composition and interaction with the cells were investigated. The studied material exhibited mechanical properties that were similar to those of trabecular bone (compressive modulus of elasticity ~0.15GPa, compressive yield strength ~3MPa) and cytocompatibility after one day that was similar to that of wrought 316L stainless steel, which is a commonly used biomaterial. Based on the obtained results, SLM is a suitable method for the fabrication of porous 316L stainless steel scaffolds with highly porous structures. PMID:27612756

  15. Microstructural Variations Across a Dissimilar 316L Austenitic: 9Cr Reduced Activation Ferritic Martensitic Steel Weld Joint

    NASA Astrophysics Data System (ADS)

    Thomas Paul, V.; Karthikeyan, T.; Dasgupta, Arup; Sudha, C.; Hajra, R. N.; Albert, S. K.; Saroja, S.; Jayakumar, T.

    2016-03-01

    This paper discuss the microstructural variations across a dissimilar weld joint between SS316 and 9Cr-RAFM steel and its modifications on post weld heat treatments (PWHT). Detailed characterization showed a mixed microstructure of austenite and martensite in the weld which is in agreement with the phases predicted using Schaeffler diagram based on composition measurements. The presence of very low volume fraction of δ-ferrite in SS316L has been identified employing state of the art electron back-scattered diffraction technique. PWHT of the ferritic steel did not reduce the hardness in the weld metal. Thermal exposure at 973 K (700 °C) showed a progressive reduction in hardness of weld joint with duration of treatment except in austenitic base metal. However, diffusion annealing at 1073 K (800 °C) for 100 hours resulted in an unexpected increase in hardness of weld metal, which is a manifestation of the dilution effects and enrichment of Ni on the transformation characteristics of the weld zone. Migration of carbon from ferritic steel aided the precipitation of fine carbides in the austenitic base metal on annealing at 973 K (700 °C); but enhanced diffusion at 1073 K (880 °C) resulted in coarsening of carbides and thereby reduction of hardness.

  16. Laser surface modification of 316 L stainless steel with bioactive hydroxyapatite.

    PubMed

    Balla, Vamsi Krishna; Das, Mitun; Bose, Sreyashree; Ram, G D Janaki; Manna, Indranil

    2013-12-01

    Laser-engineered net shaping (LENS™), a commercial additive manufacturing process, was used to modify the surfaces of 316 L stainless steel with bioactive hydroxyapatite (HAP). The modified surfaces were characterized in terms of their microstructure, hardness and apatite forming ability. The results showed that with increase in laser energy input from 32 J/mm(2) to 59 J/mm(2) the thickness of the modified surface increased from 222±12 μm to 355±6 μm, while the average surface hardness decreased marginally from 403±18 HV0.3 to 372±8 HV0.3. Microstructural studies showed that the modified surface consisted of austenite dendrites with HAP and some reaction products primarily occurring in the inter-dendritic regions. Finally, the surface-modified 316 L samples immersed in simulated body fluids showed significantly higher apatite precipitation compared to unmodified 316 L samples. PMID:24094165

  17. Corrosion resistance of 316L stainless steel with surface layer of Ni 2Al 3 or NiAl in molten carbonates

    NASA Astrophysics Data System (ADS)

    Moon, Youngjoon; Lee, Dokyol

    Double layers of nickel and aluminum are electroplated on a 316L stainless steel (316L SS) plate, which is routinely used as a separator in molten carbonate fuel cell (MCFC) stacks, and then heat-treated at 650 or 800 °C for 1 h. This results in the respective formation of a surface layer of Ni 2Al 3 or NiAl intermetallic compound, which are known to be highly corrosion-resistant in molten carbonate electrolyte. The corrosion behaviour of each plate in a molten electrolyte of (Li 0.62K 0.38) 2CO 3 or (Li 0.52Na 0.48) 2CO 3 is evaluated through immersion tests and polarisation measurements. The surface layer of Ni 2Al 3 or NiAl maintains good adhesion to the stainless steel substrate and no corrosion product is detected in any of the plates with a surface layer after immersion tests. Polarisation measurements reveal that, regardless of experimental conditions, the corrosion potentials of the plates with a surface layer shift to more positive values and the passive currents are lower than that for a bare SS plate. The corrosion rate of the NiAl surface layer is slightly lower than that of Ni 2Al 3.

  18. Texture evolution of warm-rolled and annealed 304L and 316L austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Lindell, D.

    2015-04-01

    The brass-to-copper rolling texture transition is observed during warm rolling austenitic stainless steels. In the current paper austenitic stainless steels 304L and 316L have been subjected to warm rolling at 700°C to 90% reduction. The evolution of microstructure and texture during subsequent annealing has been studied using dilatometry and electron backscatter diffraction. Recrystallisation texture for 304L was primarily cube with some retained rolling texture while 316L only had retained rolling texture. The different behaviour between the two steels is believed to originate from differences in molybdenum content.

  19. [Corrosion of stainless steel 201, 304 and 316L in the simulated sewage pipes reactor].

    PubMed

    Bao, Guo-Dong; Zuo, Jian-E; Wang, Ya-Jiao; Gan, Li-Li

    2014-08-01

    The corrosion behavior of stainless steel 201, 304 and 316L which would be used as sewer in-situ rehabilitation materials was studied in the simulated sewage pipes reactor. The corrosion potential and corrosion rate of these three materials were studied by potentiodynamic method on the 7th, 14th, 21st, 56th day under two different conditions which were full immersion condition or batch immersion condition with a 2-day cycle. The electrode process was studied by Electrochemical Impedance Spectroscopy (EIS) on the 56th day. The microstructure and composition of the corrosion pitting were analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS) on the 56th day. The results showed that 304 and 316L had much better corrosion resistance than 201 under both conditions. 304 and 316L had much smaller corrosion rate than 201 under both conditions. The corrosion resistance of all three kinds of stainless steel under the batch immersion condition was much better than those under the full immersion condition. The corrosion rate of all three kinds of stainless steel under the batch immersion condition was much smaller than those under the full immersion condition. Point pitting corrosion was formed on the surfaces of 304 and 316L. In comparison, a large area of corrosion was formed in the surface of 201. PMID:25338372

  20. Microstructure and Corrosion Resistance of Laser Additively Manufactured 316L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Trelewicz, Jason R.; Halada, Gary P.; Donaldson, Olivia K.; Manogharan, Guha

    2016-03-01

    Additive manufacturing (AM) of metal alloys to produce complex part designs via powder bed fusion methods such as laser melting promises to be a transformative technology for advanced materials processing. However, effective implementation of AM processes requires a clear understanding of the processing-structure-properties-performance relationships in fabricated components. In this study, we report on the formation of micro and nanoscale structures in 316L stainless steel samples printed by laser AM and their implications for general corrosion resistance. A variety of techniques including x-ray diffraction, optical, scanning and transmission electron microscopy, x-ray fluorescence, and energy dispersive x-ray spectroscopy were employed to characterize the microstructure and chemistry of the laser additively manufactured 316L stainless steel, which are compared with wrought 316L coupons via electrochemical polarization. Apparent segregation of Mo has been found to contribute to a loss of passivity and an increased anodic current density. While porosity will also likely impact the environmental performance (e.g., facilitating crevice corrosion) of AM alloys, this work demonstrates the critical influence of microstructure and heterogeneous solute distributions on the corrosion resistance of laser additively manufactured 316L stainless steel.

  1. Effects of Particle Sizes on Sintering Behavior of 316L Stainless Steel Powder

    NASA Astrophysics Data System (ADS)

    Park, Dong Yong; Lee, Shi W.; Park, Seong Jin; Kwon, Young-Sam; Otsuka, Isamu

    2013-03-01

    In rapidly evolving powder injection molding technology, the wide prevalence of various microstructures demands the powders of smaller particle sizes. The effects of particle size on the sintering behavior are critical to not only shape retention of microstructure but also its mechanical properties. This study investigates the effects of three different particle sizes on the sintering behavior of the 316L stainless steel (STS316L) samples, prepared by powder injection molding, via the dilatometry experiments. For this purpose, the STS316L powders of three different mean particle sizes, i.e., 2.97, 4.16, and 8.04 μm, were produced for STS316L. The samples for the dilatometry test were prepared through powder-binder mixing, injection molding, and solvent and thermal debinding. Dilatometry experiments were carried out with the samples in a H2 atmosphere at three different heating rates of 3, 6, and 10 K/min. The shrinkage data obtained by dilatometry experiments was collected and analyzed to help understand the densification and the sintering behaviors in terms of particles size and heating rate. The master sintering curve (MSC) model was used to quantify the effects of particle sizes. In addition, we investigated the microstructure evolutions in terms of particles sizes.

  2. Development of nanostructured SUS316L-2%TiC with superior tensile properties

    NASA Astrophysics Data System (ADS)

    Sakamoto, T.; Kurishita, H.; Matsuo, S.; Arakawa, H.; Takahashi, S.; Tsuchida, M.; Kobayashi, S.; Nakai, K.; Terasawa, M.; Yamasaki, T.; Kawai, M.

    2015-11-01

    Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below Md (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90-270 nm, accompanied by TiC precipitates with 20-50 nm in grain interior and 70-110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6-21%, respectively, depending on the heat treatment temperature after rolling at -196 °C.

  3. Effects of Mo content on microstructure and corrosion resistance of arc ion plated Ti-Mo-N films on 316L stainless steel as bipolar plates for polymer exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Kim, Kwang Ho; Shao, Zhigang; Wang, Feifei; Zhao, Shuang; Suo, Ni

    2014-05-01

    Bipolar plates are one of the most important components in PEMFC stack and have multiple functions, such as separators and current collectors, distributing reactions uniformly, and etc. Stainless steel is ideal candidate for bipolar plates owing to good thermal and electrical conductivity, good mechanical properties etc. However, stainless steel plate still cannot resist the corrosion of working condition. In this work, ternary Ti-Mo-N film was fabricated on 316L stainless steel (SS316L) as a surface modification layer to enhance the corrosion resistance. Effects of Mo content on the microstructure and corrosion resistance of Ti-Mo-N films are systematically investigated by altering sputtering current of the Mo target. XRD results reveal that the preferred orientation changes from [111] to [220] direction as Mo content in the film increases. The synthesized Ti-Mo-N films form a substitutional solid solution of (Ti, Mo)N where larger Mo atoms replace Ti in TiN crystal lattice. The TiN-coated SS316L sample shows the best corrosion resistance. While Mo content in the Ti-Mo-N films increases, the corrosion resistance gradually degrades. Compared with the uncoated samples, all the Ti-Mo-N film coated samples show enhanced corrosion resistance in simulated PEMFC working condition.

  4. Influences of pH value, temperature, chloride ions and sulfide ions on the corrosion behaviors of 316L stainless steel in the simulated cathodic environment of proton exchange membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Li, D. G.; Wang, J. D.; Chen, D. R.; Liang, P.

    2014-12-01

    316L stainless steel is in the passive state in a simulated cathodic environment, and the passivity of 316L SS is enhanced with increasing pH value, decreasing temperature, decreasing chloride ions and sulfide ions concentrations. Mott-Schottky plots show that the passive films appear a p-n heterojunction, and the donor and acceptor densities reach 1022 cm-3, showing a highly defective character of the passive film. The donor and acceptor densities increase with increasing temperature, increasing chloride ions and sulfide ions concentrations, while they decreased with increasing pH value. The decreased passivity and the increased doping density may be beneficial to the conductivity of the passive film, but they adversely affect the protectiveness of the passive film toward corrosion.

  5. Surface morphology and void formation in 316L stainless steel irradiated with high energy C-ions

    NASA Astrophysics Data System (ADS)

    Wang, Z. G.; Chen, K. Q.; Li, L. W.; Zhang, C. H.; Quan, J. M.; Hou, M. D.; Xu, R. H.; Ma, F.; Jin, Y. F.; Li, C. L.; Sun, Y. M.

    This work reports the study of changes of surface topography and bulk structure of 316L stainless steel (SS) irradiated at 773 K with 51.4 MeV C-ions to a fluence of 1.14 × 10 22 ions/m 2. The calculated damage levels at the surface and at the damage peak position were 0.9 and 124 displacements per atom (dpa), respectively. The changes of surface topography and bulk structure were checked at room temperature by the use of scanning probe microscopy (SPM), scanning electron microscopy (SEM), 1 MV high voltage electron microscopy (HVEM) and transmission electron microscopy (TEM) with cross-section technique. The experimental results suggested that high dose carbon ion irradiation led to (1) serious pitting, flaking, and crazing along grain boundaries of the irradiated surface; (2) voids formed in the area around the damage peak and mean void swelling is about 4%. The void swelling data deduced from the SEM and TEM observations were the same within the experimental error. Furthermore, some phase change has been detected in the carbon ion stop region. All these observed phenomena were interrelated and have been discussed.

  6. Plasma surface oxidation of 316L stainless steel for improving adhesion strength of silicone rubber coating to metal substrate

    NASA Astrophysics Data System (ADS)

    Latifi, Afrooz; Imani, Mohammad; Khorasani, Mohammad Taghi; Daliri Joupari, Morteza

    2014-11-01

    Stainless steel 316L is one of the most widely used materials for fabricating of biomedical devices hence, improving its surface properties is still of great interest and challenging in biomaterial sciences. Plasma oxidation, in comparison to the conventional chemical or mechanical methods, is one of the most efficient methods recently used for surface treatment of biomaterials. Here, stainless steel specimens were surface oxidized by radio-frequency plasma irradiation operating at 34 MHz under pure oxygen atmosphere. Surface chemical composition of the samples was significantly changed after plasma oxidation by appearance of the chromium and iron oxides on the plasma-oxidized surface. A wettable surface, possessing high surface energy (83.19 mN m-1), was observed after plasma oxidation. Upon completion of the surface modification process, silicone rubber was spray coated on the plasma-treated stainless steel surface. Morphology of the silicone rubber coating was investigated by scanning electron microscopy (SEM). A uniform coating was formed on the oxidized surface with no delamination at polymer-metal interface. Pull-off tests showed the lowest adhesion strength of coating to substrate (0.12 MPa) for untreated specimens and the highest (0.89 MPa) for plasma-oxidized ones.

  7. Creep rupture strength of activated-TIG welded 316L(N) stainless steel

    NASA Astrophysics Data System (ADS)

    Sakthivel, T.; Vasudevan, M.; Laha, K.; Parameswaran, P.; Chandravathi, K. S.; Mathew, M. D.; Bhaduri, A. K.

    2011-06-01

    316L(N) stainless steel plates were joined using activated-tungsten inert gas (A-TIG) welding and conventional TIG welding process. Creep rupture behavior of 316L(N) base metal, and weld joints made by A-TIG and conventional TIG welding process were investigated at 923 K over a stress range of 160-280 MPa. Creep test results showed that the enhancement in creep rupture strength of weld joint fabricated by A-TIG welding process over conventional TIG welding process. Both the weld joints fractured in the weld metal. Microstructural observation showed lower δ-ferrite content, alignment of columnar grain with δ-ferrite along applied stress direction and less strength disparity between columnar and equiaxed grains of weld metal in A-TIG joint than in MP-TIG joint. These had been attributed to initiate less creep cavitation in weld metal of A-TIG joint leading to improvement in creep rupture strength.

  8. Improving endothelialization on 316L stainless steel through wettability controllable coating by sol-gel technology

    NASA Astrophysics Data System (ADS)

    Wang, Mingqi; Wang, Yao; Chen, Yijie; Gu, Hongchen

    2013-03-01

    Rapid endothelialization by surface coverage is considered as a way to increase blood compatibility of the vascular stent and reduce smooth muscle cell (SMC) mediated restenosis. Coatings on 316L stainless steels with different wettabilities and similar topographies were obtained through sol-gel process by regulating the proportions of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES). Adhesion and proliferation of vascular endothelial cells (EC) and SMC on these substrates have been evaluated by cell numbers, cell morphology, and expression of cytoskeletal protein. Results showed that EC and SMC responded differently to the coated surfaces. Enhanced endothelialization of bare 316L was found at the moderately hydrophilic coating (contact angle 45.3°) which exhibited effective inhibition of SMC and negligible influence on EC. These results are expected to lay foundation for the solution of the vascular restenosis which was mainly derived from the hyperplasia of SMC.

  9. Effect of Surface Treatment on the Surface Characteristics of AISI 316L Stainless Steel

    NASA Technical Reports Server (NTRS)

    Trigwell, Steve; Selvaduray, Guna

    2005-01-01

    The ability of 316L stainless steel to maintain biocompatibility, which is dependent upon the surface characteristics, is critical to its effectiveness as an implant material. The surfaces of mechanically polished (MP), electropolished (EP) and plasma treated 316L stainless steel coupons were characterized by X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES) for chemical composition, Atomic Force Microscopy for surface roughness, and contact angle measurements for critical surface tension. All surfaces had a Ni concentration that was significantly lower than the bulk concentration of -43%. The Cr content of the surface was increased significantly by electropolishing. The surface roughness was also improved significantly by electropolishing. Plasma treatment had the reverse effect - the surface Cr content was decreased. It was also found that the Cr and Fe in the surface exist in both the oxide and hydroxide states, with the ratios varying according to surface treatment.

  10. Effect of in site strain on passivated property of the 316L stainless steels.

    PubMed

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Ting, Guo

    2016-04-01

    The effect of the strain of 316L stainless steel on its corrosion resistance in borate buffer solution was investigated by in site tensile test and the electrochemical impedance spectroscopy measurements. It was found that the corrosion resistance of the 316L stainless steel decreased with the increasing of in site strain. The lower corrosion resistance of the stainless steel during in site strain was mainly attributed to the higher doping concentration in passive film. Especially, with the increasing of in site strain, the concentrations of acceptor (i.e., cation vacancies) in the passive films significantly increased. More acceptor concentrations reduced the compactness of the passive film and its corrosion resistance. Moreover, two exponential relationships were found between in site strain and the charge transfer resistance of the passive film and between in site strain and total doping concentrations in passive film, respectively. PMID:26838820

  11. Nanosized controlled surface pretreatment of biometallic alloy 316L stainless steel.

    PubMed

    Abdel-Fattah, Tarek M; Loftis, Derek; Mahapatro, Anil

    2011-12-01

    Stainless steel (AISI 316L) is a medical grade stainless steel alloy used extensively in medical devices and in the biomedical field. 316L stainless steel was successfully electropolished via an ecologically friendly and biocompatible ionic liquid (IL) medium based on Vitamin B4 (NB4) and resulting in nanosized surface roughness and topography. Voltammetry and chronoamperometry tests determined optimum polishing conditions for the stainless steel alloy while atomic force microscopy (AFM) and scanning electron microscopy (SEM) provided surface morphology comparisons to benchmark success of each electropolishing condition. Energy dispersive X-ray analysis (EDX) combined with SEM revealed significantly smoother surfaces for each alloy surface while indicating that the constituent metals comprising each alloy effectively electropolished at uniform rates. PMID:22416578

  12. Effects of surface mechanical attrition treatment (SMAT) on a rough surface of AISI 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Arifvianto, B.; Suyitno; Mahardika, M.

    2012-03-01

    Surface mechanical attrition treatment (SMAT) improves mechanical properties of metallic materials through the formation of nanocrystallites at their surface layer. It also modifies the morphology and roughness of the work surface. Surface roughening by the SMAT has been reported previously in a smooth specimen, however in this study the starting point was a rough surface and a smoothening phenomenon is observed. In this paper, the mechanisms involved in the surface smoothening of AISI 316L stainless steel during the SMAT are elucidated. The SMAT was conducted on a specimen with a roughness of Ra = 3.98 μm for 0-20 min. The size of milling balls used in the SMAT was varied from 3.18 mm to 6.35 mm. The modification of subsurface microhardness, surface morphology, roughness and mass reduction of the specimen due to the SMAT were studied. The result shows the increasing microhardness of the surface and subsurface of the steel due to the SMAT. The impacts of milling balls deform the surface and produce a flat-like structure at this layer. Surface roughness decreases until its saturation is achieved in the SMAT. The mass reduction of the specimens is also detected and may indicate material removal or surface erosion by the SMAT. The size of milling ball is found to be the important feature determining the pattern of roughness evolution and material removal during the SMAT. From this study, two principal mechanisms in the evolution of surface morphology and roughness during the SMAT are proposed, i.e. indentation and surface erosion by the multiple impacts of milling balls. A comparative study with the results of the previous experiment indicates that the initial surface roughness has no influence in the work hardening by the SMAT but it does slightly on the saturated roughness value obtained by this treatment.

  13. Effect of a Nickel-Iron Mixture of Weld Metal on Hydrogen Permeability at Various Temperatures in 316L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Yamazaki, Takahisa; Ikeshoji, Toshi-Taka; Suzumura, Akio; Kobayashi, Daigo; Kamono, Shumpei

    It is important to prevent from hydrogen embrittlement cracking in the heat-affected zone of welded steels. The hydrogen permeation rate for bulk nickel at high temperatures is higher than that of stainless steel, although the reverse is true at low temperatures. Low carbon stainless 316L steel, which contained 12-15% nickel, was selected as the parent material for welding. We have investigated the affect of nickel near the heat-affected zone by measuring the hydrogen permeation at various temperatures. We performed hydrogen permeation tests into the bead on plate specimens using nickel filler. A stationary hydrogen gas flux through the stainless steel specimen was measured by using an orifice and a quadrupole mass spectrometer (QMS). The partial pressure difference for hydrogen that was applied to the specimen was able to be kept constant by maintaining a constant gas flow rate through the orifice in a low- pressure room. An orifice with a 3 mm diameter maintained stationary steady-state hydrogen gas flux from the specimen at 620K, while a 1.2 mm diameter orifice maintained the steady pressure at 520 K. The hydrogen permeability, K was calculated based on the measured steady-state hydrogen gas fluxes at various temperatures. These results plotted as log K versus 1/T (reciprocal temperature) could not be interpolated linearly. The permeability values of the specimen at 570 K and 520 K were less than interpolated ones between the value at 620 K and the value at 520K of the 316 L stainless steel substrate as received.

  14. Laser-driven shock waves to improve the corrosion properties of 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Peyre, Patrice; Berthe, Laurent; Fabbro, Remy; Carboni, Christelle; Bartnicki, Eric; Beranger, Gerard; Lemaitre, Christian

    1999-06-01

    Different laser pulses ranging between 0.6 and 10 ns were used to generate up to 10 GPa amplitude shock waves in an aluminum-coated 316L stainless steel with application to modify its surface behavior, especially its pitting corrosion behavior in NaCl 30g/l medium. Laser shock waves (LSW) characterizations (Hugoniot limits, Shock wave attenuations) were carried out with a VISAR system and compared with 1D simulations using Shylac Lagrangian code. Treated surfaces were analyzed through chemical spectroscopies (GDS, XPS), metallurgical characterizations (deformation bands, twins...) and residual stress measurements. Laser-induced surface modifications were also compared with the classical effects of a shot-peening at high coverage rate. Lastly, rest potential recordings, anodic polarization tests and statistical treatments of the pitting potentials were carried out to estimate the influence of a laser peening on the pitting corrosion resistance of a passive 316L alloy. It was clearly demonstrated that LSW could improve the corrosion behavior of 316L by pure mechanical effects such as compressive residual stresses which tend to reduce the nocivity of surface inclusions.

  15. Microstructure and Mechanical Properties of 316L Stainless Steel Filling Friction Stir-Welded Joints

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Nakata, K.; Tsumura, T.; Fujii, H.; Ikeuchi, K.; Michishita, Y.; Fujiya, Y.; Morimoto, M.

    2014-10-01

    Keyhole left at 316L stainless steel friction stir welding/friction stir processing seam was repaired by filling friction stir welding (FFSW). Both metallurgical and mechanical bonding characteristics were obtained by the combined plastic deformation and flow between the consumable filling tool and the wall of the keyhole. Two ways based on the original conical and modified spherical keyholes, together with corresponding filling tools and process parameters were investigated. Microstructure and mechanical properties of 316L stainless steel FFSW joints were evaluated. The results showed that void defects existed at the bottom of the refilled original conical keyhole, while excellent bonding interface was obtained on the refilled modified spherical keyhole. The FFSW joint with defect-free interface obtained on the modified spherical keyhole fractured at the base metal side during the tensile test due to microstructural refinement and hardness increase in the refilled keyhole. Moreover, no σ phase but few Cr carbides were formed in the refilled zone, which would not result in obvious corrosion resistance degradation of 316L stainless steel.

  16. Irradiation testing of 316L(N)-IG austenitic stainless steel for ITER

    NASA Astrophysics Data System (ADS)

    van Osch, E. V.; Horsten, M. G.; de Vries, M. I.

    1998-10-01

    In the frame work of the European Fusion Technology Programme and the International Thermonuclear Experimental Reactor (ITER), ECN is investigating the irradiation behaviour of the structural materials for ITER. The main structural material for ITER is austenitic stainless steel Type 316L(N)-IG. The operating temperatures of (parts of) the components are envisaged to range between 350 and 700 K. A significant part of the dose-temperature domain of irradiation conditions relevant for ITER has already been explored, there is, however, very little data at about 600 K. Available data tend to indicate a maximum in the degradation of the mechanical properties after irradiation at this temperature, e.g. a minimum in ductility and a maximum of hardening. Therefore an irradiation program for plate material 316L(N)-IG, its Electron Beam (EB) weld and Tungsten Inert Gas (TIG) weld metal, and also including Hot Isostatically Pressed (HIP) 316L(N) powder and solid-solid joints, was set up in 1995. Irradiations have been carried out in the High Flux Reactor (HFR) in Petten at a temperature of 600 K, at dose levels from 1 to 10 dpa. The paper presents the currently available post-irradiation test results. Next to tensile and fracture toughness data on plate, EB and TIG welds, first results of powder HIP material are included.

  17. Investigation on 316L/W functionally graded materials fabricated by mechanical alloying and spark plasma sintering

    NASA Astrophysics Data System (ADS)

    Tan, Chao; Wang, Guoyu; Ji, Lina; Tong, Yangang; Duan, Xuan-Ming

    2016-02-01

    316L-W (Tungsten) composite materials were fabricated by spark plasma sintering (SPS) of mechanically alloyed 316L-W powders for the development of functionally graded materials (FGMs). The effect of milling parameters on the morphology of the blended 316L/W powders and its subsequent effect on the transition between 316L and W particles during the SPS process were investigated. Samples were characterized by SEM, EDS and XRD analyses. The results so obtained show that with the increase of milling time, the mechanically activated W powder particles become thinner and smoother, with some broken fragments aggregated or inserted in the severely deformed 316L particles. A further SPS process under the conditions of 1050 °C × 45.5 MPa × 5 min leads to the densification of the powder compact and the formation of a distinguishable gray belt surrounding the retained W particles. Such a belt, which has a width of about 2-8 μm depending on different milling parameters and mainly contains Fe7W6, Fe3W3C and Fe2W phases, is bound to be a transitional region between the retained W particles and the 316L matrix. This favorable behavior with regards to the formation of a transitional belt, is accompanied by a substantial increase in the hardness values of the composite.

  18. The effects of cold rolling orientation and water chemistry on stress corrosion cracking behavior of 316L stainless steel in simulated PWR water environments

    NASA Astrophysics Data System (ADS)

    Chen, Junjie; Lu, Zhanpeng; Xiao, Qian; Ru, Xiangkun; Han, Guangdong; Chen, Zhen; Zhou, Bangxin; Shoji, Tetsuo

    2016-04-01

    Stress corrosion cracking behaviors of one-directionally cold rolled 316L stainless steel specimens in T-L and L-T orientations were investigated in hydrogenated and deaerated PWR primary water environments at 310 °C. Transgranular cracking was observed during the in situ pre-cracking procedure and the crack growth rate was almost not affected by the specimen orientation. Locally intergranular stress corrosion cracks were found on the fracture surfaces of specimens in the hydrogenated PWR water. Extensive intergranular stress corrosion cracks were found on the fracture surfaces of specimens in deaerated PWR water. More extensive cracks were found in specimen T-L orientation with a higher crack growth rate than that in the specimen L-T orientation with a lower crack growth rate. Crack branching phenomenon found in specimen L-T orientation in deaerated PWR water was synergistically affected by the applied stress direction as well as the preferential oxidation path along the elongated grain boundaries, and the latter was dominant.

  19. Effects of Ag and Cu ions on the microbial corrosion of 316L stainless steel in the presence of Desulfovibrio sp.

    PubMed

    Unsal, Tuba; Ilhan-Sungur, Esra; Arkan, Simge; Cansever, Nurhan

    2016-08-01

    The utilization of Ag and Cu ions to prevent both microbial corrosion and biofilm formation has recently increased. The emphasis of this study lies on the effects of Ag and Cu ions on the microbial corrosion of 316L stainless steel (SS) induced by Desulfovibrio sp. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were used to analyze the corrosion behavior. The biofilm formation, corrosion products and Ag and Cu ions on the surfaces were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS) and elemental mapping. Through circuit modeling, EIS results were used to interpret the physicoelectric interactions between the electrode, biofilm and culture interfaces. EIS results indicated that the metabolic activity of Desulfovibrio sp. accelerated the corrosion rate of SS in both conditions with and without ions. However, due to the retardation in the growth of Desulfovibrio sp. in the presence of Ag and Cu ions, significant decrease in corrosion rate was observed in the culture with the ions. In addition, SEM and EIS analyses revealed that the presence of the ions leads to the formation on the SS of a biofilm with different structure and morphology. Elemental analysis with EDS detected mainly sulfide- and phosphorous-based corrosion products on the surfaces. PMID:27105168

  20. Upset welded 304L and 316L vessels for storage tests

    SciTech Connect

    Kanne, W.R. Jr.

    1996-04-01

    Two sets of vessels for tritium storage tests were fabricated using upset welding. A solid-state resistance upset weld was used to join the two halves of each vessel at the girth. The vessels differ from production reservoirs in design, material, and fabrication process. One set was made from forged 304L stainless steel and the other from forged 316L stainless steel. Six vessels of each type were loaded with a tritium mix in November 1995 and placed in storage at 71 C. This memo describes and documents the fabrication of the twelve vessels.

  1. Corrosion tests of 316L and Hastelloy C-22 in simulated tank waste solutions

    SciTech Connect

    MJ Danielson; SG Pitman

    2000-02-23

    Both the 316L stainless steel and Hastelloy{reg_sign} C-22 gave satisfactory corrosion performance in the simulated test environments. They were subjected to 100 day weight loss corrosion tests and electrochemical potentiodynamic evaluation. This activity supports confirmation of the design basis for the materials of construction of process vessels and equipment used to handle the feed to the LAW-melter evaporator. BNFL process and mechanical engineering will use the information derived from this task to select material of construction for process vessels and equipment.

  2. Study of stirred layers on 316L steel created by friction stir processing

    NASA Astrophysics Data System (ADS)

    Langlade, C.; Roman, A.; Schlegel, D.; Gete, E.; Folea, M.

    2014-08-01

    Nanostructured materials are known to exhibit attractive properties, especially in the mechanical field where high hardness is of great interest. The friction stir process (FSP) is a recent surface engineering technique derived from the friction stir welding method (FSW). In this study, the FSP of an 316L austenitic stainless steel has been evaluated. The treated layers have been characterized in terms of hardness and microstructure and these results have been related to the FSP operational parameters. The process has been analysed using a Response Surface Method (RSM) to enable the stirred layer thickness prediction.

  3. Diffusion bonding of Ti coated Zircaloy-4 and 316-L stainless steel

    SciTech Connect

    Akhter, J.I. Ahmad, M.; Ali, G.

    2009-03-15

    Diffusion bonding of Zircaloy-4 and Type 316-L stainless steel was carried out by coating the joining surfaces with Ti to minimize the interlayer effect. Bonding heat treatments were carried out in vacuum at 1000 deg. C for 4 h and 1050 deg. C for 1 h. The microstructure of the diffusion zone was investigated by scanning electron microscopy and the phases in the diffusion zone were analyzed by energy dispersive spectroscopy. It is observed that Ti coating at the interface produced a dendritic structure in the diffusion zone formed in the Zircaloy-4. The concentration of the dendrites increases with an increase in bonding temperature.

  4. Fine structure analysis of biocompatible ceramic materials based hydroxyapatite and metallic biomaterials 316L

    NASA Astrophysics Data System (ADS)

    Anghelina, F. V.; Ungureanu, D. N.; Bratu, V.; Popescu, I. N.; Rusanescu, C. O.

    2013-11-01

    The aim of this paper was to obtain and characterize (surface morphology and fine structure) two types of materials: Ca10(PO4)6(OH)2 hydroxyapatite powder (HAp) as biocompatible ceramic materials and AISI 316L austenitic stainless steels as metallic biomaterials, which are the components of the metal-ceramic composites used for medical implants in reconstructive surgery and prosthetic treatment. The HAp was synthesized by coprecipitation method, heat treated at 200 °C, 800 °C and 1200 °C for 4 h, analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The stainless steel 316L type was made by casting, annealing and machined with a low speed (100 mm/s) in order to obtain a smooth surface and after that has been studied from residual stresses point of view in three polishing regimes conditions: at low speed polishing (150 rpm), at high speed polishing (1500 rpm) and high speed-vibration contact polishing (1500 rpm) using wide angle X-ray diffractions (WAXD). The chemical compositions of AISI 316 steel samples were measured using a Foundry Master Spectrometer equipped with CCD detector for spectral lines and the sparking spots of AISI 316L samples were analyzed using SEM. By XRD the phases of HAp powders have been identified and also the degree of crystallinity and average size of crystallites, and with SEM, we studied the morphology of the HAp. It has been found from XRD analysis that we obtained HAp with a high degree of crystallinity at 800 °C and 1200 °C, no presence of impurity and from SEM analysis we noticed the influence of heat treatment on the ceramic particles morphology. From the study of residual stress profiles of 316L samples were observed that it differs substantially for different machining regimes and from the SEM analysis of sparking spots we revealed the rough surfaces of stainless steel rods necessary for a better adhesion of HAp on it.

  5. Precipitation in AISI 316L(N) during creep tests at 550 and 600 °C up to 10 years

    NASA Astrophysics Data System (ADS)

    Padilha, A. F.; Escriba, D. M.; Materna-Morris, E.; Rieth, M.; Klimenkov, M.

    2007-05-01

    The precipitation behaviour in the gauge lengths and in the heads of initially solution annealed type 316L(N) austenitic stainless steel specimens tested in creep at 550 and 600 °C for periods of up to 85 000 h has been studied using several metallographic techniques. Three phases were detected: M 23C 6, Laves, and sigma phase. The volume fraction of the precipitated sigma phase was significantly higher than that of carbides and the Laves phase. M 23C 6 carbide precipitation occurred very rapidly and was followed by the sigma and Laves phases formation in the delta ferrite islands. Sigma and Laves phases precipitated at grain boundaries after longer times. Two different mechanisms of sigma phase precipitation have been proposed, one for delta ferrite decomposition and another for grain boundary precipitation. Small quantities of the Laves phase were detected in delta ferrite, at grain boundaries and inside the grains.

  6. Influence of Zn as a spallation product on the behaviour of martensitic steel T91 and austenitic steel 316L in liquid Pb-Bi

    NASA Astrophysics Data System (ADS)

    Deloffre, Ph.; Terlain, A.

    2004-11-01

    The liquid Pb-Bi alloy is proposed as material for the spallation target in hybrid systems. During the spallation process, several chemical elements are produced in the target which could generate specific liquid metal embrittlement phenomena. Among these species, zinc is known as an element which can promote LME (liquid metal embrittlement). Corrosion tests were carried out in liquid Pb-Bi in isothermal static conditions without and with 80 wppm of zinc at 150 °C, 350 °C and 600 °C up to 6000 h. No modification of the corrosion kinetics of T91 martensitic and 316L austenitic steels was observed for either unstressed or U-bend specimens with zinc in Pb-Bi. Moreover, no sign of embrittlement was observed for any of the samples with and without zinc.

  7. Correlation between distribution of nitrogen atoms implanted at high energy and high dose and nanohardness measurements into 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Pelletier, H.; Mille, P.; Muller, D.; Stoquert, J. P.; Cornet, A.; Grob, J. J.

    2001-05-01

    Ion implantation causes changes in surface composition or morphology of solids which yield to a modification of physical and particularly mechanical properties, such as hardness, Young's modulus and elastic recovery. The purpose of this study is to focus on the effects occurring during the annealing process of stainless steel 316L samples implanted with high energy (1 MeV) nitrogen ions at high dose (10 18 N cm -2). From nuclear reaction analysis (NRA) measurements, the unusual shape of N distribution is discussed in terms of diffusion and precipitation mechanisms and correlated with the physical and chemical modifications observed with glancing incidence X-ray diffraction (GIXRD). Finally, from nanoindentation measurements, the real hardness profile is extracted using the Bückle's model eliminating the substrate effect. For each specimen, we show that the hardness is the sum of two terms, the first being related to nitrogen concentration and the second to various strengthening mechanisms depending on temperature.

  8. The effect of surface roughness on the fretting corrosion of 316L stainless steel biomaterial surfaces

    NASA Astrophysics Data System (ADS)

    Shenoy, Aarti

    The medical device industry is still seeking answers to the mechanically-assisted corrosion (MAC) problem, which becomes increasingly important due to modularity in design. MAC manifests in various forms, some of which are fretting corrosion, crevice corrosion and stress corrosion. Several studies have been conducted to understand the causes and the factors that affect fretting corrosion. Some of the factors are the applied load, surface potential, oxide film characteristics and solution chemistry near the interface. Surface properties such as surface roughness determine the topography of the surface and the nature of asperity-asperity contact, which is a factor that would determine the mechanically assisted corrosion behavior of the interface, like the stem-neck and head-neck taper junctions in modular hip replacement devices. This study aims to understand the correlation between surface roughness of 316L stainless steel samples and fretting corrosion behavior using a variable load pin-on-disc test. It was found that the smoother surfaces are associated with lower fretting currents. However, smoother surfaces also created the conditions for fretting initiated crevice corrosion to occur more readily. Fretting corrosion regimes and the severity are thus dependent upon the surface roughness. A possible explanation could be due to the inverse relationship between the interasperity distance parameter, Delta, and fretting currents. The coefficient of friction between the two surfaces in contact however remained unaffected by surface roughness, but decreased with increasing load. Smoother surfaces, while lowering fretting corrosion reactions can enhance crevice corrosion reactions in 316L stainless steel interfaces.

  9. Fabrication of antibacterial and hydrophilic electroless Ni-B coating on 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Bülbül, Ferhat; Bülbül, Leman Elif

    2016-01-01

    Biomaterial-associated bacterial infection is one of the most common complications with medical vehicles and implants made of stainless steel. A surface coating treatment like electroless Ni-B deposition, a new candidate to be used in a broad range of engineering applications owing to many advantages such as low cost, thickness uniformity, good wear resistance, may improve the antibacterial activity and physical properties of biomedical devices made of stainless steel. In this study, the antibacterial property of the electroless Ni-B film coated on AISI 316L (UNS S31603) stainless steel is basically investigated. Inhibition halo diameter measurement after incubation at 37 °C and 24 h demonstrates the existence of antimicrobial activity of the electroless Ni-B coating deposited on 316L stainless steel over the Escherichia coli test bacteria. The results of X-ray diffraction, scanning electron microscopy, atomic force microscopy and microhardness measurement studies confirms that the coating deposited on the substrate has an uniform amorphous and a harder structure. Besides, the wettability property of the uncoated substrate and the coating was measured as the contact angle of water. The water contact angle reduced about from 97.7 to 69.25°.

  10. Improvement in cavitation erosion resistance of AISI 316L stainless steel by friction stir processing

    NASA Astrophysics Data System (ADS)

    Hajian, M.; Abdollah-zadeh, A.; Rezaei-Nejad, S. S.; Assadi, H.; Hadavi, S. M. M.; Chung, K.; Shokouhimehr, M.

    2014-07-01

    Commercial AISI 316L plates with the initial grain size of 14.8 μm were friction stir processed (FSP) with different processing parameters, resulting in two fine-grained microstructures with the grain sizes of 4.6 and 1.7 μm. The cavitation erosion behavior, before and after FSP, was evaluated in terms of incubation time, cumulative mass loss and mean depth of erosion. A separate cavitation erosion test was performed on the transverse cross section of a FSP sample to reveal the effect of grain structure. It was observed that FSP samples, depending on their grain size, are at least 3-6 times more resistant than the base material against cavitation erosion. The improvement in cavitation erosion resistance is attributed to smaller grain structure, lower fraction of twin boundaries, and favorable crystallographic orientation of grains in FSP samples. The finer the grain size, the more cavitation erosion resistance was achieved. Moreover, the microstructures of eroded surfaces were studied using a scanning electron microscope equipped with EBSD, and an atomic force microscope. The mechanisms controlling the cavitation erosion damage in friction stir processed AISI 316L are also discussed.

  11. Mechanical properties and biocompatibility of plasma-nitrided laser-cut 316L cardiovascular stents.

    PubMed

    Arslan, Erdem; Iğdil, Mustafa C; Yazici, Hilal; Tamerler, Candan; Bermek, Hakan; Trabzon, Levent

    2008-05-01

    The effect of surface modification of laser-cut 316L cardiovascular stents by low-T plasma nitriding was evaluated in terms of mechanical properties and biocompatibility of the stents. The plasma nitriding was performed at 400, 450 or 500 degrees C using various ratios of nitrogen-hydrogen gas mixtures. The flexibility and radial strength were measured in crimped and expanded state of the stents, respectively. The mechanical properties could be adjusted and improved by plasma nitriding conducted at temperatures lower than 450 degrees C and/or nitrogen content less than 10% in the treatment gas. An osteoblast cell culture model system was utilized to investigate the effect of plasma nitriding of the stents on the biological response towards the stents, using biological criteria such as cell viability, alkaline phosphatase and nitric oxide production. In terms of cell viability and alkaline phosphatase production, the plasma nitriding procedure did not appear to negatively affect the biocompatibility of the 316L steel stents. However, in terms of nitric oxide production that was slightly increased in the presence of the plasma-nitrided stents, an indirect improvement in the biocompatibility could possibly be expected. PMID:17968502

  12. Surface modification of biomedical AISI 316L stainless steel with zirconium carbonitride coatings

    NASA Astrophysics Data System (ADS)

    Wang, L.; Zhao, X.; Ding, M. H.; Zheng, H.; Zhang, H. S.; Zhang, B.; Li, X. Q.; Wu, G. Y.

    2015-06-01

    In the paper, by using radio frequency (rf) magnetron sputtering method, a zirconium carbonitride coating was produced on AISI 316L austenitic stainless steel. The influence of substrate temperature (Ts) on microstructure, mechanical properties, corrosion resistance and hemocompatibility were then investigated. XRD and TEM results revealed that the zirconium carbonitride coatings were almost amorphous when Ts was below 400°C, while nanostructured Zr2CN was formed at Ts of 400 °C. The nanocrystalline formation resulted in a significant increase in the nanohardness of zirconium carbonitride coatings from 17 GPa to over 32 GPa. Electrochemical testing showed that the stable zirconium carbonitride coating had improved the corrosion resistance of AISI 316L stainless steel substrate material. The characterization of platelet adhesion indicated that the zirconium carbonitride coatings presented better hemocompatibility when Ts varied from 25 °C to more than 200 °C, which may be due to the lower surface roughness, interfacial tension and the rate γsd /γsp , where γsd and γsp are the disperse component and polar component of the surface, respectively.

  13. Partially degradable friction-welded pure iron-stainless steel 316L bone pin.

    PubMed

    Nasution, A K; Murni, N S; Sing, N B; Idris, M H; Hermawan, H

    2015-01-01

    This article describes the development of a partially degradable metal bone pin, proposed to minimize the occurrence of bone refracture by avoiding the creation of holes in the bone after pin removal procedure. The pin was made by friction welding and composed of two parts: the degradable part that remains in the bone and the nondegradable part that will be removed as usual. Rods of stainless steel 316L (nondegradable) and pure iron (degradable) were friction welded at the optimum parameters: forging pressure = 33.2 kPa, friction time = 25 s, burn-off length = 15 mm, and heat input = 4.58 J/s. The optimum tensile strength and elongation was registered at 666 MPa and 13%, respectively. A spiral defect formation was identified as the cause for the ductile fracture of the weld joint. A 40-µm wide intermetallic zone was identified along the fusion line having a distinct composition of Cr, Ni, and Mo. The corrosion rate of the pin gradually decreased from the undeformed zone of pure iron to the undeformed zone of stainless steel 316L. All metallurgical zones of the pin showed no toxic effect toward normal human osteoblast cells, confirming the ppb level of released Cr and Ni detected in the cell media were tolerable. PMID:24757071

  14. Stability of passivated 316L stainless steel oxide films for cardiovascular stents.

    PubMed

    Shih, Chun-Che; Shih, Chun-Ming; Chou, Kuang-Yi; Lin, Shing-Jong; Su, Yea-Yang

    2007-03-15

    Passivated 316L stainless steel is used extensively in cardiovascular stents. The degree of chloride ion attack might increase as the oxide film on the implant degrades from exposure to physiological fluid. Stability of 316L stainless steel stent is a function of the concentration of hydrated and hydrolyated oxide concentration inside the passivated film. A high concentration of hydrated and hydrolyated oxide inside the passivated oxide film is required to maintain the integrity of the passivated oxide film, reduce the chance of chloride ion attack, and prevent any possible leaching of positively charged ions into the surrounding tissue that accelerate the inflammatory process. Leaching of metallic ions from corroded implant surface into surrounding tissue was confirmed by the X-ray mapping technique. The degree of thrombi weight percentage [W(ao): (2.1 +/- 0.9)%; W(ep): (12.5 +/- 4.9)%, p < 0.01] between the amorphous oxide (AO) and the electropolishing (EP) treatment groups was statistically significant in ex-vivo extracorporeal thrombosis experiment of mongrel dog. The thickness of neointima (T(ao): 100 +/- 20 microm; T(ep): 500 +/- 150 microm, p < 0.01) and the area ratio of intimal response at 4 weeks (AR(ao): 0.62 +/- 0.22; AR(ep): 1.15 +/- 0.42, p < 0.001) on the implanted iliac stents of New Zealand rabbit could be a function of the oxide properties. PMID:17072844

  15. Tritium release from SS316 under vacuum condition

    SciTech Connect

    Torikai, Y.; Penzhorn, R.D.

    2015-03-15

    The plasma facing surface of the ITER vacuum vessel, partly made of low carbon austenitic stainless steel type 316L, will incorporate tritium during machine operation. In this paper the kinetics of tritium release from stainless steel type 316 into vacuum and into a noble gas stream are compared and modelled. Type 316 stainless steel specimens loaded with tritium either by exposure to 1.2 kPa HT at 573 K or submersion into liquid HTO at 298 K showed characteristic thin surface layers trapping tritium in concentrations far higher than those determined in the bulk. The evolution of the tritium depth profile in the bulk during heating under vacuum was non-discernible from that of tritium liberated into a stream of argon. Only the relative amount of the two released tritium-species, i.e. HT or HTO, was different. Temperature-dependent depth profiles could be predicted with a one-dimensional diffusion model. Diffusion coefficients derived from fitting of the tritium release into an evacuated vessel or a stream of argon were found to be (1.4 ± 1.0)*10{sup -7} and (1.3 ± 0.9)*10{sup -9} cm{sup 2}/s at 573 and 423 K, respectively. Polished surfaces on type SS316 stainless steel inhibit considerably the thermal release rate of tritium.

  16. Tensile properties of explosively formed 316L(N)-IG stainless steel with and without an electron beam weld

    NASA Astrophysics Data System (ADS)

    Hegeman, J. B. J.; Luzginova, N. V.; Jong, M.; Groeneveld, H. D.; Borsboom, A.; Stuivinga, M. E. C.; van der Laan, J. G.

    2011-10-01

    The mechanical properties of two explosively formed saddle shaped 60 mm thick plates of 316L(N)-IG steel with and without an electron beam weld have been investigated. Two different conditions have been characterized: (1) Reference condition and (2) ITER relevant condition. The reference material exhibits consistent results for both plates, mechanical properties of reference material are similar to the properties previously observed for 316L(N)-IG steels. No significant difference in mechanical properties and microstructure between different positions in the 60 mm plate is observed. Tensile properties for ITER relevant materials are found to comply both with the RCC-MR code qualified data for 316L(N) steel used for the structural design and with ITER Materials Properties Handbook. As expected total elongation and uniform elongation for weld material are lower than the average curves obtained for the base material.

  17. Improved corrosion resistance of 316L stainless steel by nanocrystalline and electrochemical nitridation in artificial saliva solution

    NASA Astrophysics Data System (ADS)

    Lv, Jinlong; Liang, Tongxiang

    2015-12-01

    The fluoride ion in artificial saliva significantly changed semiconductor characteristic of the passive film formed on the surface of 316L stainless steels. The electrochemical results showed that nanocrystalline α‧-martensite improved corrosion resistance of the stainless steel in a typical artificial saliva compared with coarse grained stainless steel. Moreover, comparing with nitrided coarse grained stainless steel, corrosion resistance of the nitrided nanocrystalline stainless steel was also improved significantly, even in artificial saliva solution containing fluoride ion. The present study showed that the cryogenic cold rolling and electrochemical nitridation improved corrosion resistance of 316L stainless steel for the dental application.

  18. Exploring linear rake machining in 316L austenitic stainless steel for microstructure scale-refinement, grain boundary engineering, and surface modification

    NASA Astrophysics Data System (ADS)

    Facco, Giovanni Giuseppe

    Thermo-mechanical processing plays an important role in materials property optimization through microstructure modification, required by demanding modern materials applications. Extreme grain size refinement, grain boundary engineering, and surface modification have been explored to establish enhanced performance properties for numerous metals and alloys in order to meet challenges associated with improving degradation resistance and increasing lifetime in harsh environments. Due to the critical role of austenitic stainless steels, such as 316L, as structural components in harsh environments, e.g. in nuclear power plants, improved degradation resistance is desirable. Linear raking, a novel two dimensional plane strain machining process, has shown promise achieving significant grain size refinement through severe plastic deformation (SPD) and imparting large strains in the surface and near surface regions of the substrate in various metals and alloys, imparting enhanced properties. Here, the effects of linear rake machining on the microstructure and related properties of 316L are investigated systematically for the first time. The controlled variation of linear raking processing parameters in combination with detailed micro-characterization using analytical electron microscopy, x-ray diffraction and associated property measurements enables the determination of the influence of changes in strain and strain rate on the developing deformation microstructure and related properties. Varying the linear raking process parameters, and consequently the strain and strain rate, affects the volume fractions of deformation induced alpha'-martensite and the degree of grain refinement, to the nanoscale, through SPD in the chips produced. Additionally, linear raking is identified as a way to produce surface modified structures in the specimen substrate surface of 316L, with observations of various degrees of deformation and strain up to a depth of 150microm. This research clearly

  19. Creep of 304 LN and 316 L stainless steels at cryogenic temperatures

    SciTech Connect

    Roth, L.D.; Manhardt, A.E.; Dalder, E.N.C.; Kershaw, R.P. Jr.

    1985-08-07

    Creep behavior of Type 304 LN plate and 316 L shielded-metal-arc (SMA)-deposited stainless weld metal was investigated at 4/sup 0/K. Testing was performed at constant load in a creep machine with a cryostat designed for long-term stability. Both transient and steady-state creep were observed during tests lasting over 2000 hours. Steady-state creep rates were much greater than expected from extrapolations of 300-K creep data. Creep rates on the order of 10/sup -10/ s/sup -1/ were observed at stresses around the yield stress for both materials. The stress exponent under these conditions if approx.2.3. Possible creep mechanisms at this temperature and the impact of these results on the design of engineering structures for long-term structural stability at cryogenic temperatures are discussed.

  20. Dissolution of a 316L stainless steel vessel by a pool of molten aluminum

    SciTech Connect

    Tutu, N.K.; Finfrock, C.C.; Lara, J.D.; Schwarz, C.E.; Greene, G.A.

    1993-01-01

    Two experiments to study the dissolution of a torospherical stainless steel vessel by an isothermal pool of molten aluminum have been performed. The test vessels consisted of 24 inch diameter 316L stainless steel ``ASME Flanged and Dished Heads.`` The nominal values of the average melt temperatures for the two tests were: 977{degree}C and 1007{degree}C. The measurements of the dissolution depth as a function of the position along the vessel surface showed the dissolution to be spatially highly non-uniform. Large variations in the dissolution depth with respect to the azimuthal coordinate were also observed. The maximum value of the measured time averaged dissolution rate was found to be 5.05 mm/hr, and this occurred near the edge of the molten pool. The concentration measurements indicated that the molten pool was highly stratified with respect to the concentration of stainless steel in the melt (molten aluminum-stainless steel solution).

  1. Fatigue properties of a biomedical 316L steel processed by surface mechanical attrition

    NASA Astrophysics Data System (ADS)

    Sun, Z.; Chemkhi, M.; Kanoute, P.; Retraint, D.

    2014-08-01

    This work deals with the influence of surface mechanical attrition treatment (SMAT) on fatigue properties of a medical grade 316L stainless steel. Metallurgical parameters governed by SMAT such as micro-hardness and nanocrystalline layer are characterized using different techniques. Low cycle fatigue tests are performed to investigate the fatigue properties of untreated and SMAT-processed samples. The results show that the stress amplitude of SMAT- processed samples with two different treatment intensities is significantly enhanced compared to untreated samples, while the fatigue strength represented by the number of cycles to failure is not improved in the investigated strain range. The enhancement in the stress amplitude of treated samples can be attributed to the influence of the SMAT affected layer.

  2. Relative Defect Density Measurements of Laser Shock Peened 316L Stainless Steel Using Positron Annihilation Spectroscopy

    SciTech Connect

    Marcus A. Gagliardi; Bulent H. Sencer; A. W. Hunt; Stuart A. Maloy; George T. Gray III

    2011-12-01

    The surface of an annealed 316L stainless steel coupon was laser shock peened and Vickers hardness measurements were subsequently taken of its surface. This Vickers hardness data was compared with measurements taken using the technique of positron annihilation Doppler broadening spectroscopy. When compared, a correlation was found between the Vickers hardness data measurements and those made using Doppler broadening spectroscopy. Although materials with a high defect density can cause the S-parameter measurements to saturate, variations in the Sparameter measurements suggest that through further research the Doppler broadening technique could be used as a viable alternative to measuring a material's hardness. In turn, this technique, could be useful in industrial settings where surface hardness and surface defects are used to predict lifetime of components.

  3. Explosive bonding of 316L to C18150 CuCrZr alloy for ITER applications.

    SciTech Connect

    Puskar, Joseph David; Butler, Don J.; Goods, Steven Howard; Brasher, Dave G.

    2010-10-01

    Recent developments in the ITER experimental fusion reactor require that a 316L stainless steel substructure be bonded to a precipitation strengthened CuCrZr heat sink alloy, C18150. This bond defines the cooling water pressure boundary. Given the importance of this interface, a variety of experiments with fusion welding and solid-state joining techniques have been performed. Analysis of the joints includes mechanical measurements of bond strength and microstructural analysis using optical and electron microscopy techniques. A particular emphasis was placed on the mechanical properties of the CuCrZr, since it undergoes additional thermal processing and cannot be solutionized and aged hardened per standard heat treatments. It was determined that the explosion bonding, of all the techniques examined, maximized the residual mechanical strength of the CuCrZr. The bonding parameters were optimized to minimize the amount of mixing and porosity at the interface. The details of these results and the optimization will be discussed.

  4. Effects of applied potential on SCC and HE for STS 316L in seawater

    NASA Astrophysics Data System (ADS)

    Han, Min-Su; Park, Jae-Cheul; Jang, Seok-Ki; Kim, Seong-Jong

    2010-05-01

    Offshore structures that are made of austenitic stainless steels are exposed to a severe corrosion environment, with fracturing of the passive film occurring by chloride ion intrusion, stress from dynamic external forces and fatigue due to wave and tidal forces. In this paper, we report our evaluation of the durability of STS 316L with respect to stress corrosion cracking and hydrogen embrittlement in natural seawater, which was carried out via electrochemical methods and slow strain rate tests (SSRTs). The effect of hydrogen on the material was assessed using a SSRT with an applied potential of -0.95 V (versus Ag/AgCl). In addition, potentials below an applied potential of -1.2 V indicate samples that are affected by atomic and molecular hydrogen. Theoretically, the optimum corrosion protection range possible without stress corrosion cracking and hydrogen embrittlement occurring is thought to be between-0.56 and -0.9 V.

  5. Controlling the electrodeposition, morphology and structure of hydroxyapatite coating on 316L stainless steel.

    PubMed

    Thanh, Dinh Thi Mai; Nam, Pham Thi; Phuong, Nguyen Thu; Que, Le Xuan; Anh, Nguyen Van; Hoang, Thai; Lam, Tran Dai

    2013-05-01

    Hydroxyapatite (HAp) coatings were prepared on 316L stainless steel (316LSS) substrates by electrochemical deposition in the solutions containing Ca(NO3)2·4H2O and NH4H2PO4 at different electrolyte concentrations. Along with the effect of precursor concentration, the influence of temperature and H2O2 content on the morphology, structure and composition of the coating was thoroughly discussed with the help of X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra. The in vitro tests in simulated body fluids (SBF) were carried out and then the morphological and structural changes were estimated by SEM and electrochemical techniques (open circuit potential, polarization curves, Nyquist and Bode spectra measurements). Being simple and cost-effective, this method is advantageous for producing HAp implant materials with good properties/characteristics, aiming towards in vivo biomedical applications. PMID:23498230

  6. Parylene coatings on stainless steel 316L surface for medical applications--mechanical and protective properties.

    PubMed

    Cieślik, Monika; Kot, Marcin; Reczyński, Witold; Engvall, Klas; Rakowski, Wiesław; Kotarba, Andrzej

    2012-01-01

    The mechanical and protective properties of parylene N and C coatings (2-20 μm) on stainless steel 316L implant materials were investigated. The coatings were characterized by scanning electron and confocal microscopes, microindentation and scratch tests, whereas their protective properties were evaluated in terms of quenching metal ion release from stainless steel to simulated body fluid (Hanks solution). The obtained results revealed that for parylene C coatings, the critical load for initial cracks is 3-5 times higher and the total metal ions release is reduced 3 times more efficiently compared to parylene N. It was thus concluded that parylene C exhibits superior mechanical and protective properties for application as a micrometer coating material for stainless steel implants. PMID:23177768

  7. Material Corrosion and Plate-Out Test of Types 304L and 316L Stainless Steel

    SciTech Connect

    Zapp, P.E.

    2001-02-06

    Corrosion and plate-out tests were performed on 304L and 316L stainless steel in pretreated Envelope B and Envelope C solutions. Flat coupons of the two stainless steels were exposed to 100 degrees C liquid and to 74 degrees C and 88 degrees C vapor above the solutions for 61 days. No significant corrosion was observed either by weight-loss measurements or by microscopic examination. Most coupons had small weight gains due to plate-out of solids, which remained to some extent even after 24-hour immersion in 1 N nitric acid at room temperature. Plate-out was more significant in the Envelope B coupons, with film thickness from less than 0.001 in. to 0.003-inches.

  8. Process mapping of laser surface modification of AISI 316L stainless steel for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chikarakara, Evans; Naher, Sumsun; Brabazon, Dermot

    2010-11-01

    A 1.5-kW CO2 laser in pulsed mode at 3 kHz was used to investigate the effects of varied laser process parameters and resulting morphology of AISI 316L stainless steel. Irradiance and residence time were varied between 7.9 to 23.6 MW/cm2 and 50 to 167 μs, respectively. A strong correlation between irradiance, residence time, depth of processing and roughness of processed steel was established. The high depth of altered microstructure and increased roughness were linked to higher levels of both irradiance and residence times. Energy fluence and surface temperature models were used to predict levels of melting occurring on the surface through the analysis of roughness and depth of the region processed. Microstructural images captured by the SEM revealed significant grain structure changes at higher irradiances, but due to increased residence times, limited to the laser in use, the hardness values were not improved.

  9. Corrosion resistance improvement for 316L stainless steel coronary artery stents by trimethylsilane plasma nanocoatings

    PubMed Central

    Jones, John Eric; Chen, Meng; Yu, Qingsong

    2015-01-01

    To improve their corrosion resistance and thus long-term biocompatibility, 316L stainless steel coronary artery stents were coated with trimethylsilane (TMS) plasma coatings of 20–25 nm in thickness. Both direct current (DC) and radio-frequency (RF) glow discharges were utilized for TMS plasma coatings and additional NH3/O2 plasma treatment to tailor the surface properties. X-ray photoelectron spectroscopy (XPS) was used to characterize the coating surface chemistry. It was found that both DC and RF TMS plasma coatings had Si- and C-rich composition, and the O-and N-contents on the surfaces were substantially increased after NH3/O2 plasma treatment. Surface contact angle measurements showed that DC TMS plasma nanocoating with NH3/O2 plasma treatment generated very hydrophilic surface. The corrosion resistance of TMS plasma coated stents was evaluated through potentiodynamic polarization and electro-chemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization demonstrated that the TMS plasma coated stents imparted higher corrosion potential and pitting potential, as well as lower corrosion current densities as compared with uncoated controls. The surface morphology of stents before and after potentiodynamic polarization testing was analyzed with scanning electron microscopy, which indicated less corrosion on coated stents than uncoated controls. It was also noted that, from EIS data, the hydrophobic TMS plasma nanocoatings showed stable impedance modulus at 0.1 Hz after 21 day immersion in an electrolyte solution. These results suggest improved corrosion resistance of the 316L stainless steel stents by TMS plasma nanocoatings and great promise in reducing and blocking metallic ions releasing into the bloodstream. PMID:24500866

  10. Electron stimulated desorption of H 3O + from 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Cole, C. R.; Outlaw, R. A.; Champion, R. L.; Holloway, B. C.; Kelly, M. A.

    2007-02-01

    Surface ions generated by electron stimulated desorption from mass spectrometer ion source grids are frequently observed, but often misidentified. For example, in the case of mass 19, the source is often assumed to be surface fluorine, but since the metal oxide on grid surfaces has been shown to form water and hydroxides, a more compelling case can be made for the formation of hydronium. Further, fluorine is strongly electronegative, so it is rarely generated as a positive ion. A commonly used metal for ion source grids is 316L stainless steel. Thermal vacuum processing by bakeout or radiation heating from the filament typically alters the surface composition to predominantly Cr 2O 3. X-ray photoelectron spectral shoulders on the O 1s and Cr 2p 3/2 peaks can be attributed to adsorbed water and hydroxides, the intensity of which can be substantially increased by hydrogen dosing. On the other hand, the sub-peak intensities are substantially reduced by heating and/or by electron bombardment. Electron bombardment diode measurements show an initial work function increase corresponding to predominant hydrogen desorption (H 2) and a subsequent work function decrease corresponding to predominant oxygen desorption (CO). The fraction of hydroxide concentration on the surface was determined from X-ray photoelectron spectroscopy and from the deconvolution of temperature desorption spectra. Electron stimulated desorption yields from the surface show unambiguous H 3O + peaks that can be significantly increased by hydrogen dosing. Time of flight secondary ion mass spectrometry sputter yields show small signals of H 3O +, as well as its constituents (H +, O + and OH +) and a small amount of fluorine as F -, but no F + or F + complexes (HF +, etc.). An electron stimulated desorption cross-section of σ+ ˜ 1.4 × 10 -20 cm 2 was determined for H 3O + from 316L stainless steel for hydrogen residing in surface chromium hydroxide.

  11. Corrosion resistance improvement for 316L stainless steel coronary artery stents by trimethylsilane plasma nanocoatings.

    PubMed

    Eric Jones, John; Chen, Meng; Yu, Qingsong

    2014-10-01

    To improve their corrosion resistance and thus long-term biocompatibility, 316L stainless steel coronary artery stents were coated with trimethylsilane (TMS) plasma coatings of 20-25 nm in thickness. Both direct current (DC) and radio-frequency (RF) glow discharges were utilized for TMS plasma coatings and additional NH₃/O₂ plasma treatment to tailor the surface properties. X-ray photoelectron spectroscopy (XPS) was used to characterize the coating surface chemistry. It was found that both DC and RF TMS plasma coatings had Si- and C-rich composition, and the O- and N-contents on the surfaces were substantially increased after NH₃/O₂ plasma treatment. Surface contact angle measurements showed that DC TMS plasma nanocoating with NH₃/O₂ plasma treatment generated very hydrophilic surface. The corrosion resistance of TMS plasma coated stents was evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization demonstrated that the TMS plasma coated stents imparted higher corrosion potential and pitting potential, as well as lower corrosion current densities as compared with uncoated controls. The surface morphology of stents before and after potentiodynamic polarization testing was analyzed with scanning electron microscopy, which indicated less corrosion on coated stents than uncoated controls. It was also noted that, from EIS data, the hydrophobic TMS plasma nanocoatings showed stable impedance modulus at 0.1 Hz after 21 day immersion in an electrolyte solution. These results suggest improved corrosion resistance of the 316L stainless steel stents by TMS plasma nanocoatings and great promise in reducing and blocking metallic ions releasing into the bloodstream. PMID:24500866

  12. A Microstructural Study on the Observed Differences in Charpy Impact Behavior Between Hot Isostatically Pressed and Forged 304L and 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cooper, Adam J.; Cooper, Norman I.; Bell, Andrew; Dhers, Jean; Sherry, Andrew H.

    2015-11-01

    With near-net shape technology becoming a more desirable route toward component manufacture due to its ability to reduce machining time and associated costs, it is important to demonstrate that components fabricated via Hot Isostatic Pressing (HIP) are able to perform to similar standards as those set by equivalent forged materials. This paper describes the results of a series of Charpy tests from HIP'd and forged 304L and 316L austenitic stainless steel, and assesses the differences in toughness values observed. The pre-test and post-test microstructures were examined to develop an understanding of the underlying reasons for the differences observed. The as-received microstructure of HIP'd material was found to contain micro-pores, which was not observed in the forged material. In tested specimens, martensite was detectable within close proximity to the fracture surface of Charpy specimens tested at 77 K (-196 °C), and not detected in locations remote from the fracture surface, nor was martensite observed in specimens tested at ambient temperatures. The results suggest that the observed changes in the Charpy toughness are most likely to arise due to differences in as-received microstructures of HIP'd vs forged stainless steel.

  13. Comparison of Strength and Serration at Cryogenic Temperatures among 304L, 316L and 310S Steels

    NASA Astrophysics Data System (ADS)

    Shibata, K.; Ogata, T.; Nyilas, A.; Yuri, T.; Fujii, H.; Ohmiya, S.; Onishi, T.; Weiss, K. P.

    2008-03-01

    Tensile tests of 310S steel were performed at temperatures below 300 K and the yield strength and deformation behavior were compared with those of 304L and 316L steels. Computer simulations were also carried out to graph stress-elongation curves in order to discuss the effects of martensitic transformations induced during deformation on their strengths and deformation behavior at low temperatures. Tensile tests showed that yield strength of 310S steel is highest and that of 304L is lowest. The differences in yield strengths between 316L and 310S steels and between 304L and 316L steels are larger than those expected from the differences in solid solution strengthening. This can be explained by the effect of the strain through γ to ɛ martensitic transformation induced by elastic stress in 304L and 316L steels. The strength level and the shape of stress-elongation curves at cryogenic temperatures excluding serration can be qualitatively revealed by simulation when higher strength of ɛ phase comparing to α' phase and the window effect of α' were considered simultaneously. In liquid hydrogen, the three steels exhibit large serrations on the stress-elongation curves after the deformation near to the ultimate stress, while the curves are smooth before the onset of the serration. Such serrations in liquid hydrogen could not be revealed by simulation.

  14. Biocompatibility evaluation of surface-treated AISI 316L austenitic stainless steel in human cell cultures.

    PubMed

    Martinesi, M; Bruni, S; Stio, M; Treves, C; Bacci, T; Borgioli, F

    2007-01-01

    The effects of AISI 316L austenitic stainless steel, tested in untreated state or subjected to glow-discharge nitriding (at 10 or 20 hPa) and nitriding + post-oxidizing treatments, on human umbilical vein endothelial cells (HUVEC) and on peripheral blood mononuclear cells (PBMC) were evaluated. All the treated samples showed a better corrosion resistance in PBS and higher surface hardness in comparison with the untreated alloy. In HUVEC put in contact for 72 h with the sample types, proliferation and apoptosis decreased and increased, respectively, in the presence of the nitrided + post-oxidized samples, while only slight differences in cytokine (TNF-alpha, IL-6, and TGF-beta1) release were registered. Intercellular adhesion molecule-1 (ICAM-1) increased in HUVEC incubated with all the treated samples, while vascular cell adhesion molecule-1 (VCAM-1) and E-selectin increased in the presence of all the sample types. PBMC incubated for 48 h with the samples showed a decrease in proliferation and an increase in apoptosis in the presence of the untreated samples and the nitrided + post-oxidized ones. All the sample types induced a remarkable increase in TNF-alpha and IL-6 release in PBMC culture medium, while only the untreated sample and the nitrided at 10 hPa induced an increase in ICAM-1 expression. In HUVEC cocultured with PBMC, previously put in contact with the treated AISI 316L samples, increased levels of ICAM-1 were detected. In HUVEC coincubated with the culture medium of PBMC, previously put in contact with the samples under study, a noteworthy increase in ICAM-1, VCAM-1, and E-selectin levels was always registered, with the exception of VCAM-1, which was not affected by the untreated sample. In conclusion, even if the treated samples do not show a marked increase in biocompatibility in comparison with the untreated alloy, their higher corrosion resistance may suggest a better performance as the contact with physiological environment becomes longer. PMID

  15. The influence of surface condition on the localized corrosion of 316L stainless steel orthopaedic implants.

    PubMed

    Beddoes, J; Bucci, K

    1999-07-01

    The localized corrosion of austenitic stainless steel 316L intended for use as orthopaedic implants is determined as a function of the surface condition and metallurgical state. From the examination of samples exposed to a ferric chloride solution, at both 22 and 37 degrees C, the independent contribution of crevice and pitting corrosion to localized corrosion is determined. Both forms of localized corrosion occur to a greater extent at the higher temperature. The results indicate that weight loss measurements may not be sufficient to determine the extent of crevice corrosion separately from the influence of pitting corrosion. More importantly, the surface conditions required for the best resistance to crevice or pitting corrosion differ. Electropolished surfaces provide the best resistance to crevice corrosion, while "bead blasted" surfaces provide the best resistance to pitting corrosion. The implication of this result in terms of the serviceability as orthopaedic implants is discussed. The current results indicate the cold-worked state exhibits improved resistance to pitting corrosion. However, the influence of the metallurgical state could not be separated from a possible compositional effect. PMID:15348123

  16. SCC crack growth rate of cold worked 316L stainless steel in PWR environment

    NASA Astrophysics Data System (ADS)

    Du, Donghai; Chen, Kai; Yu, Lun; lu, Hui; Zhang, Lefu; Shi, Xiuqiang; Xu, Xuelian

    2015-01-01

    Many component failures in nuclear power plants were found to be caused by stress corrosion cracking (SCC) of cold worked austenitic steels. Some of the pressure boundary component materials are even cold worked up to 35% plastic deformation, leaving high residual stress and inducing high growth rate of corrosion crack. Controlling water chemistry is one of the best counter measure to mitigate this problem. In this work, the effects of temperature (200 up to 325 °C) and dissolved oxygen (0 up to 2000 μg/L) on SCC crack growth rates of cold worked austenitic stainless steel type 316L have been tested by using direct current potential drop (DCPD) method. The results showed that temperature affected SCC crack growth rates more significantly in oxygenated water than in deaerated water. In argon deaerated water, the crack growth rate exhibited a peak at about 250 °C, which needs further verification. At 325 °C, the SCC crack growth rate increased rapidly with the increase of dissolved oxygen concentration within the range from 0 up to 200 μg/L, while when dissolved oxygen was above 200 μg/L, the crack growth rate followed a shallower dependence on dissolved oxygen concentration.

  17. Electrophoretic deposition of bioactive glass coating on 316L stainless steel and electrochemical behavior study

    NASA Astrophysics Data System (ADS)

    Mehdipour, Mehrad; Afshar, Abdollah; Mohebali, Milad

    2012-10-01

    In this research, submicron bioactive glass (BG) particles were synthesized by a sol-gel process and were then coated on a 316L stainless steel substrate using an electrophoretic deposition (EPD) technique. Stable suspension of bioactive glass powders in ethanol solvent was prepared by addition of triethanol amine (TEA), which increased zeta potential from 16.5 ± 1.6 to 20.3 ± 1.4 (mv). Thickness, structure and electrochemical behavior of the coating were characterized. SEM studies showed that increasing EPD voltage leads to a coating with more agglomerated particles, augmented porosity and micro cracks. The results of Fourier transformed infrared (FTIR) spectroscopy revealed the adsorption of TEA via methyl and amid groups on bioactive glass particles. Presence of bioactive glass coating reduced corrosion current density (icorr) and shifted corrosion potential (Ecorr) toward more noble values in artificial saliva at room temperature. Percent porosity of the coating measured by potentiodynamic polarization technique increased as EPD voltage was raised. The results of impedance spectroscopic studies demonstrated that the coating acts as a barrier layer in artificial saliva.

  18. Spinodal decomposition in AISI 316L stainless steel via high-speed laser remelting

    NASA Astrophysics Data System (ADS)

    Chikarakara, Evans; Naher, Sumsun; Brabazon, Dermot

    2014-05-01

    A 1.5 kW CO2 pulsed laser was used to melt the surface of AISI 316L stainless steel with a view to enhancing the surface properties for engineering applications. A 90 μm laser beam spot size focused onto the surface was used to provide high irradiances (up to 23.56 MW/cm2) with low residence times (as low as 50 μs) in order to induce rapid surface melting and solidification. Variations in microstructure at different points within the laser treated region were investigated. From this processing refined lamellar and nodular microstructures were produced. These sets of unique microstructures were produced within the remelted region when the highest energy densities were selected in conjunction with the lowest residence times. The transformation from the typical austenitic structure to much finer unique lamellar and nodular structures was attributed to the high thermal gradients achieved using these selected laser processing parameters. These structures resulted in unique characteristics including elimination of cracks and a reduction of inclusions within the treated region. Grain structure reorientation between the bulk alloy and laser-treated region occurred due to the induced thermal gradients. This present article reports on microstructure forms resulting from the high-speed laser surface remelting and corresponding underlying kinetics.

  19. Structural and magnetic characterization of plasma ion nitrided layer on 316L stainless steel alloy

    NASA Astrophysics Data System (ADS)

    Öztürk, O.; Okur, S.; Riviere, J. P.

    2009-05-01

    In this study, an FeCrNi alloy (316L stainless steel disc) was nitrided in a low-pressure R.F. plasma at 430 °C for 72 min under a gas mixture of 60% N2-40% H2. Structural, compositional and magnetic properties of the plasma nitrided layer was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and magnetic force microscopy (MFM). The magnetic behaviour of the nitrided layer was also investigated with a vibrating sample magnetometer (VSM). Combined X-ray diffraction, cross-sectional SEM, AFM and MFM, as well as VSM analyses provide strong evidence for the formation of the γN phase, [γN-(Fe, Cr, Ni)], with mainly ferromagnetic characteristics. The uniform nature of the γN layer is clearly demonstrated by the XRD, cross-sectional SEM and AFM analyses. Based on the AFM and SEM data, the thickness of the γN layer is found to be ∼6 μm. According to the MFM and VSM analyses, ferromagnetism in the γN layer is revealed by the observation of stripe domain structures and the hysteresis loops. The cross-sectional MFM results demonstrate the ferromagnetic γN phase distributed across the plasma nitrided layer. The MFM images show variation in the size and form of the magnetic domains from one grain to another.

  20. Welding of 316L Austenitic Stainless Steel with Activated Tungsten Inert Gas Process

    NASA Astrophysics Data System (ADS)

    Ahmadi, E.; Ebrahimi, A. R.

    2015-02-01

    The use of activating flux in TIG welding process is one of the most notable techniques which are developed recently. This technique, known as A-TIG welding, increases the penetration depth and improves the productivity of the TIG welding. In the present study, four oxide fluxes (SiO2, TiO2, Cr2O3, and CaO) were used to investigate the effect of activating flux on the depth/width ratio and mechanical property of 316L austenitic stainless steel. The effect of coating density of activating flux on the weld pool shape and oxygen content in the weld after the welding process was studied systematically. Experimental results indicated that the maximum depth/width ratio of stainless steel activated TIG weld was obtained when the coating density was 2.6, 1.3, 2, and 7.8 mg/cm2 for SiO2, TiO2, Cr2O3, and CaO, respectively. The certain range of oxygen content dissolved in the weld, led to a significant increase in the penetration capability of TIG welds. TIG welding with active fluxes can increase the delta-ferrite content and improves the mechanical strength of the welded joint.

  1. Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

    PubMed

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

    2014-07-01

    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries. PMID:24404766

  2. Rolling of 316L Stainless Steel with Rough Rolls to Potentially Obtain Superficial Nanograins

    NASA Astrophysics Data System (ADS)

    Camurri, Carlos; Gallegos, Alejo; Carrasco, Claudia

    2014-06-01

    316L stainless steel plates of 5-mm thickness, normalized at 900 °C, were cold rolled with different reductions and number of passes using rolls with three different surface roughnesses: grain heights of 0.17 and 0.33 mm and rhomboid-shaped grains of 1.5-mm height. Subsequently, the rolled samples were annealed at 275 °C for 1 h in an effort to achieve superficial nanograins. The plates laminated using low-roughness rolls had continuous superficial microcrystallization when they were rolled for at least 26 passes. For samples made with rougher rolls, the recrystallized superficial grains formed on the surface (sized ~10-15 μm) were smaller than those below the surface; this behavior was caused by the major deformation induced by repeated indentations. The superficial recrystallization of the sample also tended to be more continuous for higher number of passes; micrographs of the penetration profiles of indentation in the samples rolled with high-roughness rolls revealed that a sample rolled 24 times had not yet reached the steady surface topology. As a conclusion, in order to successfully form superficial nanograins, very low-roughness rolls must be used as well as a small absolute reduction per pass, followed by annealing. These rolling conditions generate a continuous field of highly superficial deformations, which act as nucleation centers for nanograins during annealing.

  3. Structural analysis and intergranular corrosion tests of AISI 316L steel.

    PubMed

    Stonawská, Z; Svoboda, M; Sozańska, M; Krístková, M; Sojka, J; Dagbert, C; Hyspecká, L

    2006-10-01

    Pure AISI 316L steel is investigated after solution heat treatment (1050 degrees C/H(2)O) and structural sensitization (650 degrees C). Two quite different intergranular corrosion tests are used to determine the degree of structural sensitization due to the precipitation of secondary phases along the grain boundaries (mainly the M(23)C(6) and sigma-phase): the oxalic acid etch test and the electrochemical potentio-kinetic reactivation test. Generally, the dissolution of chromium-rich carbides (M(23)C(6)) is provoked by oxalic acid etch tests, whereas the chromium-depleted zones, in the vicinity of chromium-rich carbides (M(23)C(6)), are attacked by electrochemical potentio-kinetic reactivation tests. Both intergranular corrosion tests are used to determine the maximum degree of structural sensitization. Thus structural analysis by carbon replicas reveals the Laves phase, and both the M(23)C(6) and (Cr,Mo)(x)(Fe,Ni)(y) phases. The results of intergranular corrosion tests are related to the findings of the structural analysis. PMID:17100908

  4. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel.

    PubMed

    Blanda, Giuseppe; Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia; Piazza, Salvatore; Sunseri, Carmelo; Inguanta, Rosalinda

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO4·H2O; HA, Ca10(PO4)6(OH)2) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO3)2·4H2O and NH4H2PO4 by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50°C for all deposition times, while at 25°C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. PMID:27127032

  5. Low-Temperature Aging Characteristics of Type 316L Stainless Steel Welds: Dependence on Solidification Mode

    NASA Astrophysics Data System (ADS)

    Abe, Hiroshi; Watanabe, Yutaka

    2008-06-01

    Thermal aging embrittlement of light water reactor (LWR) components made of stainless steel cast has been recognized as a potential degradation issue, and careful attention has been paid to it. Although welds of austenitic stainless steels have γ-δ duplex microstructure, which is similar to that of the stainless steel cast, examination of the thermal aging characteristics of the stainless steel welds is very limited. In this investigation, two types of type 316L stainless steel weld metal with different solidification modes were prepared using two kinds of filler metals having tailored Ni equivalent and Cr equivalent. Differences between the two weld metals in the morphology of microstructure, in the composition of δ-ferrite, and in hardening behaviors with isothermal aging at 335 °C have been investigated. The hardness of the ferrite phase has increased with aging time, while the hardness of austenite phase has stayed the same. The mottled aspect has been observed in δ-ferrite of aged samples by transmission electron microscopy (TEM) observation. These characteristics suggest that spinodal decomposition has occurred in δ-ferrite by aging at 335 °C. The age-hardening rate of δ-ferrite was faster for the primary austenite solidification mode (AF mode) sample than the primary ferrite solidification mode (FA mode) sample in the initial stage of the aging up to 2000 hours. It has been suggested that the solidification mode can affect the kinetics of spinodal decomposition.

  6. On microstructure-property correlation of thermally aged type 316L stainless steel weld metal

    NASA Astrophysics Data System (ADS)

    Gill, T. P. S.; Vijayalkshmi, M.; Rodriguez, P.; Padmanabhan, K. A.

    1989-06-01

    This paper deals with the microstructural changes and consequent deterioration in the room temperature tensile properties of type 316L stainless steel weld metal when exposed to elevated temperatures (773 to 973 K) for prolonged periods (up to 5000 hours). The microstructure-property correlation derived in this study is based on a variety of techniques: Magne-Gage, electrochemical extraction, X-ray diffraction, tensile testing, and both optical and electron microscopy. It has been established that the amount and morphology of the sigma phase are the key factors in determining the changes in the strength levels, total elongation, and extent of work hardening. The amount and morphology of sigma, in turn, is seen to depend on the relative kinetics of the various transformations, such as dissolution of delta-ferrite, growth of carbides, etc., shape changes in sigma, and the relative stabilities of the phases at the corresponding temperature of aging. The complicated dependence of the tensile properties on the microstrutural changes has been explained with direct quantitative evidence.

  7. Structural, electrical and magnetic measurements on oxide layers grown on 316L exposed to liquid lead-bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Hosemann, Peter; Hofer, Christian; Hlawacek, Gregor; Li, Ning; Maloy, Stuart A.; Teichert, Christian

    2012-02-01

    Fast reactors and spallation neutron sources may use lead-bismuth eutectic (LBE) as a coolant. Its physical, chemical, and irradiation properties make it a safe coolant compared to Na cooled designs. However, LBE is a corrosive medium for most steels and container materials. The present study was performed to evaluate the corrosion behavior of the austenitic steel 316L (in two different delivery states). Detailed atomic force microscopy, magnetic force microscopy, conductive atomic force microscopy, and scanning transmission electron microscopy analyses have been performed on the oxide layers to get a better understanding of the corrosion and oxidation mechanisms of austenitic and ferritic/martensitic stainless steel exposed to LBE. The oxide scale formed on the annealed 316L material consisted of multiple layers with different compositions, structures, and properties. The innermost oxide layer maintained the grain structure of what used to be the bulk steel material and shows two phases, while the outermost oxide layer possessed a columnar grain structure.

  8. Microstructural evolution and hardness changes in the interface of Cu/316L joint materials under aging and ion irradiation

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Yoshiie, T.; Muroga, T.; Yoshida, N.; Iwai, T.; Edwards, D. J.

    2004-08-01

    The effects of aging and ion irradiation on microstructure stability and hardness change in the joint materials of CuNiBe/316L and CuAl25/316L have been investigated in the present study. The aging at 673 K for 1000 h or Ni ion irradiation at 573 and 673 K to 10 dpa did not promote the interdiffusion and void swelling at the interface. The hardness in both Cu alloys and stainless steel was increased by irradiation, however, it was decreased by aging except for CuNiBe alloy. The hardness change in CuNiBe alloy was larger than that in CuAl25 alloy. The hardness changes would have a significant effect on the mechanical properties of joint materials.

  9. Result of International Round Robin Test on Young's Modulus Measurement of 304L and 316L Steels at Cryogenic Temperatures

    SciTech Connect

    Shibata, K.; Ogata, T.; Nyilas, A.; Walsh, R. P.; Toplosky, V. J.; Millet, M. F.; Shindo, Y.; Fujii, H.; Ohmiya, S.; Ishio, K.; Nakajima, H.; Takano, K.; Mitterbacher, H.; Gigante, P.

    2006-03-31

    Ogata et al. reported in 1996 results of international Round Robin tests on mechanical property measurement of several metals at cryogenic temperatures. Following the report, the standard deviation of Young's modulus of 316L steel is much larger than those of yield and tensile strengths, that is, 4.6 % of the mean value for Young's modulus, while 1.4 % and 1.6 % of the mean values for yield and for tensile strengths, respectively. Therefore, an international Round Robin test on Young's modulus of two austenitic stainless steels at cryogenic temperatures under the participation often institutes from four nations has been initiated within these two years. As a result, the ratios of standard deviation to the mean values are 4.2 % for 304L and 3.6 % for 316L. Such a drop in the standard deviation is attributable to the decrease in the number of institute owing to the application of single extensometer or direct strain gage technique.

  10. Influence of ageing on the quasistatic fracture toughness of an SS 316(N) weld at ambient and elevated temperatures

    NASA Astrophysics Data System (ADS)

    Sasikala, G.; Ray, S. K.

    2011-01-01

    The leak before break analysis of SS 316L(N) components of the prototype fast breeder reactor requires the elastic plastic fracture toughness parameter J for 0.2 mm crack extension, J0.2, especially for the welds, at the operating temperatures. The J- R curves for the welds produced using the consumable developed by Indira Gandhi Centre for Atomic Research, were determined in the as-welded condition as well as after thermal ageing (923 K/4200 h) conditions at 298 K and 643 K, using unloading compliance method for 298 K and normalization method for 643 K. The aged material exhibited pop-in crack extensions of magnitudes that, according to ASTM E1820 standard, could be ignored for multi-specimen data analysis for determining J0.2. Therefore, for this condition, J nom- Δ a curves were established using the multiple specimen method and also single specimen normalization method; for the latter, a modification earlier developed by the authors for accounting for small pop-in crack extensions was used. The value of J0.2 from both methods showed excellent reproducibility. Ageing is seen to reduce the toughness of this material considerably at both the testing temperatures.

  11. CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY CHROME (VI) REDUCTANT SOLUTION USING 304 AND 316L STAINLESS STEEL

    SciTech Connect

    DUNCAN JB; WYRAS RB

    2007-10-08

    This report documents the laboratory testing and analyses as directed under the test plan, RPP PLAN-34065, and documented in laboratory notebooks HNF 2742 and HNF-N-473-1. The purpose of this study was to evaluate and compare the electrochemical corrosion and pitting susceptibility of the 304 and 316L stainless steel in the acidified reducing solution that will be contained in either the secondary waste receiving tank or concentrate tank.

  12. Effect of forming technique BixSiyOz coatings obtained by sol- gel and supported on 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Bautista Ruiz, J.; Olaya Flórez, J.; Aperador, W.

    2016-02-01

    BixSiyOz type coatings via sol-gel synthesized from bismuth nitrate pentahydrate, and tetraethyl orthosilicate as precursors; glacial acetic acid and 2-ethoxyethanol as solvents, and ethanolamine as complexing. The coatings were supported on AISI 316L stainless steel substrate through dip-coating and spin-coating techniques. The study showed that the spin-coating technique is efficient than dip-coating because it allows more dense and homogeneous films.

  13. Electrochemical study of Type 304 and 316L stainless steels in simulated body fluids and cell cultures.

    PubMed

    Tang, Yee-Chin; Katsuma, Shoji; Fujimoto, Shinji; Hiromoto, Sachiko

    2006-11-01

    The electrochemical corrosion behaviour of Type 304 and 316L stainless steels was studied in Hanks' solution, Eagle's minimum essential medium (MEM), serum containing medium (MEM with 10% of fetal bovine serum) without cells, and serum containing medium with cells over a 1-week period. Polarization resistance measurements indicated that the stainless steels were resistant to Hanks' and MEM solutions. Type 304 was more susceptible to pitting corrosion than Type 316L in Hanks' and MEM solutions. The uniform corrosion resistance of stainless steels, determined by R(p), was lower in culturing medium than in Hanks' and MEM. The low corrosion resistance was due to surface passive film with less protective to reveal high anodic dissolution rate. When cells were present, the initial corrosion resistance was low, but gradually increased after 3 days, consistent with the trend of cell coverage. The presence of cells was found to suppress the cathodic reaction, that is, oxygen reduction, and increase the uniform corrosion resistance as a consequence. On the other hand, both Type 304 and 316L stainless steels became more susceptible to pitting corrosion when they were covered with cells. PMID:16935040

  14. The high temperature three point bend testing of proton irradiated 316L stainless steel and Mod 9Cr 1Mo

    NASA Astrophysics Data System (ADS)

    Maloy, Stuart A.; Zubelewicz, A.; Romero, T.; James, M. R.; Sommer, W. F.; Dai, Y.

    2005-08-01

    The predicted operating conditions for a lead-bismuth eutectic target to be used in an accelerator driven system for the Advanced Fuel Cycle Initiative span a temperature range of 300-600 °C while being irradiated by a high energy (˜600 MeV) proton beam. Such spallation conditions lead to high displacement rates coupled with high accumulation rates of helium and hydrogen up to 150 appm/dpa. Some candidate materials for these applications include Mod9Cr-1Mo and 316L stainless steel. To investigate the effect of irradiation on these materials, the mechanical properties are being measured through three point bend testing on Mod 9Cr-1Mo and 316L at 25, 250, 350 and 500 °C after irradiation in a high energy proton beam (500-800 MeV) to a dose of 9.8 dpa at temperatures from 200 to 320 °C. By comparing measurements made in bending to tensile measurements measured on identically irradiated materials, a measurement of 0.2% offset yield stress was obtained from 0.05% offset yield stress measured in three point bend testing. Yield stress increased by more than a factor of two after irradiation to 9.8 dpa. Observation of the outer fiber surface of 316L showed very localized deformation when tested after irradiation at 70 °C and deformation on multiple slip systems when tested after irradiation at 250-320 °C.

  15. Formation of Expanded Austenite on a Cold-Sprayed AISI 316L Coating by Low-Temperature Plasma Nitriding

    NASA Astrophysics Data System (ADS)

    Adachi, Shinichiro; Ueda, Nobuhiro

    2015-12-01

    Low-temperature plasma nitriding at temperatures below 450 °C is commonly applied to austenitic stainless steels to enhance wear resistance, while maintaining corrosion resistance, by forming expanded austenite (known as the S-phase). In this work, low-temperature plasma nitriding of cold-sprayed AISI 316L coatings was examined. A cold-spray technique was developed to produce metal coatings with less oxidation. However, the cold-sprayed AISI 316L coating obtained by use of nitrogen gas as propellant contained many interconnected pores and cracks, and was, consequently, unsuitable as an anticorrosive coating. Therefore, laser post-treatment was used to modify the coating and increase its density to similar to that of bulk steel. The anticorrosive performance of this coating on a carbon steel substrate in NaCl solution was substantially improved. Subsequent low-temperature plasma nitriding enhanced the wear resistance by two orders of magnitude. It is concluded that cold-sprayed AISI 316L coatings treated by laser post-treatment and subsequent low-temperature plasma nitriding could be used as protective coatings under severe wear and corrosion conditions.

  16. Emissivity calibration for temperature measurement using infrared thermography in orthogonal cutting of 316L and 100Cr6 grinding

    NASA Astrophysics Data System (ADS)

    Valiorgue, Frédéric; Brosse, Alexandre; Rech, Joël; Hamdi, Hédi; Bergheau, Jean Michel

    2011-01-01

    Material removal operations such as turning or grinding are prone to generate very high temperatures at the tool/chip and tool/workpiece interfaces. These phenomena are involved in studies concerning tools or workpieces, and their estimation is a key point for predicting damages. Temperature elevation is the main cause in workpieces worsening because it generates residual stresses and metallurgical modifications. It is also linked to the tools wear because of the thermal fatigue phenomena and the thermally activated diffusion process. In this paper, a first attempt to measure the temperature fields during 316L orthogonal cutting and 100Cr6 grinding is presented and can be divided in three parts. In the first part the physics of temperature measurement using infrared thermography are presented. Then, the calibration of the infrared camera is realized and allows to obtain of the emissivity curves of 316L and 100Cr6 steels. To do so, an experimental device has been set up to reproduce the luminance recording conditions encountered during the machining operations. The last step is the computation of all the experimental data to obtain the temperature fields from the recorded luminance and the 316L and 100Cr6 emissivity curve. At last, temperature level measured is compared to those presented in the bibliography.

  17. Influence of mercury velocity on compatibility with type 316L/316LN stainless steel in a flow loop

    NASA Astrophysics Data System (ADS)

    Pawel, S. J.; Taleyarkhan, R. P.; Felde, D. K.; Manneschmidt, E. T.

    2003-05-01

    Previous experiments to examine corrosion resulting from thermal gradient mass transfer of type 316L stainless steel in mercury were conducted in thermal convection loops (TCLs) with an Hg velocity of about 1 m/min. These tests have now been supplemented with a series of experiments designed to examine the influence of increased flow velocity and possible cavitation conditions on compatibility. In one experiment, the standard TCL design was modified to include a reduced section in the hot leg that provided a concomitant increase in the local velocity by a factor of five. In addition, a pumped-loop experiment was operated with a flow velocity of about 1 m/s. Finally, a TCL was modified to include an ultrasonic transducer at the top of the hot leg in an attempt to generate cavitation conditions with corresponding extreme local velocity associated with collapsing bubbles. The results indicate that compatibility of type 316L/316LN stainless steel does not depend significantly on liquid metal velocity in the range of 1 m/min to 1 m/s. Benchtop cavitation experiments revealed susceptibility of 316L coupons to significant weight losses and increases in surface roughness as a result of 24 h exposure to 1.5 MPa pressure waves in Hg generated ultrasonically at 20 kHz. However, attempts to generate cavitation conditions on coupons inside the TCL with the ultrasonic transducer proved largely unsuccessful.

  18. Laser Surface Treatment of Stellite 6 Coating Deposited by HVOF on 316L Alloy

    NASA Astrophysics Data System (ADS)

    Shoja-Razavi, Reza

    2016-07-01

    This research aimed to study the effects of laser glazing treatment on microstructure, hardness, and oxidation behavior of Stellite 6 coating deposited by high velocity oxygen fuel (HVOF) spraying. The as-sprayed Stellite 6 coating (ST-HVOF) was subjected to single-pass and multiple-pass laser treatments to achieve the optimum glazing parameters. Microstructural characterizations were performed by x-ray diffractometry and field emission scanning electron microscopy equipped with energy-dispersive spectroscopy. Two-step optimization showed that laser treatment at the power of 200 W with a scan rate of 4 mm/s causes a surface layer with a thickness of 208 ± 32 µm to be remelted, while the underlying layers retain the original ST-HVOF coating structure. The obtained sample (ST-Glazing) exhibited a highly dense and uniform structure with an extremely low porosity of ~0.3%, much lower than that of ST-HVOF coating (2.3%). The average microhardness of ST-Glazing was measured to be 519 Hv0.3 indicating a 17% decrease compared to ST-HVOF (625 Hv0.3) due to the residual stress relief and dendrite coarsening from submicron size to ~3.4 µm after laser treatment. The lowest oxidation mass gain was obtained for ST-Glazing by 2 mg/cm2 after 8 cycles at 900 °C indicating 52 and 84% improvement in oxidation resistance in comparison to ST-HVOF and bare 316L steel substrates, respectively.

  19. The effect of hydrogen peroxide on uranium oxide films on 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Wilbraham, Richard J.; Boxall, Colin; Goddard, David T.; Taylor, Robin J.; Woodbury, Simon E.

    2015-09-01

    For the first time the effect of hydrogen peroxide on the dissolution of electrodeposited uranium oxide films on 316L stainless steel planchets (acting as simulant uranium-contaminated metal surfaces) has been studied. Analysis of the H2O2-mediated film dissolution processes via open circuit potentiometry, alpha counting and SEM/EDX imaging has shown that in near-neutral solutions of pH 6.1 and at [H2O2] ⩽ 100 μmol dm-3 the electrodeposited uranium oxide layer is freely dissolving, the associated rate of film dissolution being significantly increased over leaching of similar films in pH 6.1 peroxide-free water. At H2O2 concentrations between 1 mmol dm-3 and 0.1 mol dm-3, formation of an insoluble studtite product layer occurs at the surface of the uranium oxide film. In analogy to corrosion processes on common metal substrates such as steel, the studtite layer effectively passivates the underlying uranium oxide layer against subsequent dissolution. Finally, at [H2O2] > 0.1 mol dm-3 the uranium oxide film, again in analogy to common corrosion processes, behaves as if in a transpassive state and begins to dissolve. This transition from passive to transpassive behaviour in the effect of peroxide concentration on UO2 films has not hitherto been observed or explored, either in terms of corrosion processes or otherwise. Through consideration of thermodynamic solubility product and complex formation constant data, we attribute the transition to the formation of soluble uranyl-peroxide complexes under mildly alkaline, high [H2O2] conditions - a conclusion that has implications for the design of both acid minimal, metal ion oxidant-free decontamination strategies with low secondary waste arisings, and single step processes for spent nuclear fuel dissolution such as the Carbonate-based Oxidative Leaching (COL) process.

  20. Laser Surface Treatment of Stellite 6 Coating Deposited by HVOF on 316L Alloy

    NASA Astrophysics Data System (ADS)

    Shoja-Razavi, Reza

    2016-05-01

    This research aimed to study the effects of laser glazing treatment on microstructure, hardness, and oxidation behavior of Stellite 6 coating deposited by high velocity oxygen fuel (HVOF) spraying. The as-sprayed Stellite 6 coating (ST-HVOF) was subjected to single-pass and multiple-pass laser treatments to achieve the optimum glazing parameters. Microstructural characterizations were performed by x-ray diffractometry and field emission scanning electron microscopy equipped with energy-dispersive spectroscopy. Two-step optimization showed that laser treatment at the power of 200 W with a scan rate of 4 mm/s causes a surface layer with a thickness of 208 ± 32 µm to be remelted, while the underlying layers retain the original ST-HVOF coating structure. The obtained sample (ST-Glazing) exhibited a highly dense and uniform structure with an extremely low porosity of ~0.3%, much lower than that of ST-HVOF coating (2.3%). The average microhardness of ST-Glazing was measured to be 519 Hv0.3 indicating a 17% decrease compared to ST-HVOF (625 Hv0.3) due to the residual stress relief and dendrite coarsening from submicron size to ~3.4 µm after laser treatment. The lowest oxidation mass gain was obtained for ST-Glazing by 2 mg/cm2 after 8 cycles at 900 °C indicating 52 and 84% improvement in oxidation resistance in comparison to ST-HVOF and bare 316L steel substrates, respectively.

  1. Effect of Post-Weld Heat Treatment on Mechanical and Electrochemical Properties of Gas Metal Arc-Welded 316L (X2CrNiMo 17-13-2) Stainless Steel

    NASA Astrophysics Data System (ADS)

    Muhammad, F.; Ahmad, A.; Farooq, A.; Haider, W.

    2016-08-01

    In the present research work, corrosion behavior of post-weld heat-treated (PWHT) AISI 316L (X2CrNiMo 17-13-2) specimens joined by gas metal arc welding is compared with as-welded samples by using potentiodynamic polarization technique. Welded samples were PWHT at 1323 K for 480 s and quenched. Mechanical properties, corrosion behavior and microstructures of as-welded and PWHT specimens were investigated. Microstructural studies have shown grain size refinement after PWHT. Ultimate tensile strength and yield strength were found maximum for PWHT samples. Bend test have shown that PWHT imparted ductility in welded sample. Fractographic analysis has evidenced ductile behavior for samples. Potentiodynamic polarization test was carried out in a solution composed of 1 M H2SO4 and 1 N NaCl. Corrosion rate of weld region was 127.6 mpy, but after PWHT, it was decreased to 13.12 mpy.

  2. Nanohardness, corrosion and protein adsorption properties of CuAlO2 films deposited on 316L stainless steel for biomedical applications

    NASA Astrophysics Data System (ADS)

    Chang, Shih-Hang; Chen, Jian-Zhang; Hsiao, Sou-Hui; Lin, Guan-Wei

    2014-01-01

    This study preliminarily assesses the biomedical applications of CuAlO2 coatings according to nanoindentation, electrochemical, and protein adsorption tests. Nanoindentation results revealed that the surface hardness of 316L stainless steel increased markedly after coating with CuAlO2 films. Electrochemical tests of corrosion potential, breakdown potential, and corrosion current density showed that the corrosion resistance properties of 316L stainless steel are considerably improved by CuAlO2 coatings. Bicinchoninic acid (BCA) protein assay results revealed that the protein adsorption behavior of 316L stainless steel did not exhibit notable differences with or without CuAlO2 coatings. A CuAlO2 coating of 100 nm thickness improved the surface nanohardness and corrosion resistance ability of 316L stainless steel. CuAlO2 is a potential candidate for biomaterial coating applications, particularly for surface modification of fine, delicate implants.

  3. Effect of grain refinement and electrochemical nitridation on corrosion resistance of the 316L stainless steel for bipolar plates in PEMFCs environment

    NASA Astrophysics Data System (ADS)

    Jinlong, Lv; Tongxiang, Liang; Hongyun, Luo

    2015-10-01

    The stain-induced nanocrystalline α'-martensite was obtained by cryogenic cold rolling at liquid-nitrogen temperature for 316L stainless steel. The electrochemical results showed nanocrystalline 316L stainless steel deteriorated its corrosion resistance in a typical proton exchange membrane fuel cell environment compared with coarse grained one. However, comparing with electrochemically nitrided coarse grained stainless steel, electrochemically nitrided nanocrystalline stainless steel improved significantly corrosion resistance in the same environment, which was supported further by Mott-Shottky analysis. X-ray photoelectron spectroscopy analysis revealed that the nanocrystalline promoted the enrichment of nitrogen and chromium and inhibited form of NH3 on the surface, which could significantly improve the corrosion resistance of the 316L stainless steel. The present study showed that the electrochemically nitrided 316L stainless steel was more suitable for the bipolar plates in proton exchange membrane fuel cell environment than the untreated one, especially for nanocrystalline stainless steel.

  4. The effect of CO2 laser beam welded AISI 316L austenitic stainless steel on the viability of fibroblast cells, in vitro.

    PubMed

    Köse, Ceyhun; Kaçar, Ramazan; Zorba, Aslı Pınar; Bağırova, Melahat; Allahverdiyev, Adil M

    2016-03-01

    It has been determined by the literature research that there is no clinical study on the in vivo and in vitro interaction of the cells with the laser beam welded joints of AISI 316L biomaterial. It is used as a prosthesis and implant material and that has adequate mechanical properties and corrosion resistance characteristics. Therefore, the interaction of the CO2 laser beam welded samples and samples of the base metal of AISI 316L austenitic stainless steel with L929 fibroblast cells as an element of connective tissue under in vitro conditions has been studied. To study the effect of the base metal and the laser welded test specimens on the viability of the fibroblast cells that act as an element of connective tissues in the body, they were kept in DMEMF-12 medium for 7, 14, 28 days and 18 months. The viability study was experimentally studied using the MTT method for 7, 14, 28 days. In addition, the direct interaction of the fibroblast cells seeded on 6 different plates with the samples was examined with an inverted microscope. The MTT cell viability experiment was repeated on the cells that were in contact with the samples. The statistical relationship was analyzed using a Tukey test for the variance with the GraphPad statistics software. The data regarding metallic ion release were identified with the ICP-MS method after the laser welded and main material samples were kept in cell culture medium for 18 months. The cell viability of the laser welded sample has been detected to be higher than that of the base metal and the control based on 7th day data. However, the laser welded sample's viability of the fibroblast cells has diminished by time during the test period of 14 and 28 days and base metal shows better viability when compared to the laser welded samples. On the other hand, the base metal and the laser welded sample show better cell viability effect when compared to the control group. According to the ICP-MS results of the main material and laser welded

  5. One-dimensional migration of interstitial clusters in SUS316L and its model alloys at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Satoh, Y.; Abe, H.; Matsukawa, Y.; Matsunaga, T.; Kano, S.; Arai, S.; Yamamoto, Y.; Tanaka, N.

    2015-05-01

    For self-interstitial atom (SIA) clusters in various concentrated alloys, one-dimensional (1D) migration is induced by electron irradiation around 300 K. But at elevated temperatures, the 1D migration frequency decreases to less than one-tenth of that around 300 K in iron-based bcc alloys. In this study, we examined mechanisms of 1D migration at elevated temperatures using in situ observation of SUS316L and its model alloys with high-voltage electron microscopy. First, for elevated temperatures, we examined the effects of annealing and short-term electron irradiation of SIA clusters on their subsequent 1D migration. In annealed SUS316L, 1D migration was suppressed and then recovered by prolonged irradiation at 300 K. In high-purity model alloy Fe-18Cr-13Ni, annealing or irradiation had no effect. Addition of carbon or oxygen to the model alloy suppressed 1D migration after annealing. Manganese and silicon did not suppress 1D migration after annealing but after short-term electron irradiation. The suppression was attributable to the pinning of SIA clusters by segregated solute elements, and the recovery was to the dissolution of the segregation by interatomic mixing under electron irradiation. Next, we examined 1D migration of SIA clusters in SUS316L under continuous electron irradiation at elevated temperatures. The 1D migration frequency at 673 K was proportional to the irradiation intensity. It was as high as half of that at 300 K. We proposed that 1D migration is controlled by the competition of two effects: induction of 1D migration by interatomic mixing and suppression by solute segregation.

  6. Study of scale formation on AISI 316L in simulated solid oxide fuel cell bi-polar environments

    SciTech Connect

    Ziomek-Moroz, M.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Bullard, Sophie J.; Singh , P.; Windisch, C.F., Jr.

    2004-01-01

    Significant progress made towards reducing the operating temperature of solid oxide fuel cells (SOFC) from {approx}1000 C to {approx}600 C is expected to permit the use of metallic materials with substantial cost reduction. One of the components in a SOFC stack to be made of metallic materials is a bipolar separator, also called an interconnect. It provides electrical connection between individual cells and serves as a gas separator to prevent mixing of the fuel and air. At operating temperature, the material selected for interconnects should possess good chemical and mechanical stability in complex fuel and oxidant gaseous environments, good electrical conductivity, and a coefficient of thermal expansion (CTE) that matches that of the cathode, anode, and electrolyte components. Cr2O3 scale-forming alloys appear to be the most promising candidates. There appears to be a mechanism whereby the environment on the fuel side of a stainless steel interconnect changes the corrosion behavior of the metal on the air side. The corrosion behavior of 316L stainless steel simultaneously exposed to air on one side and H2+3%H2O on the other at 907 K was studied using X-ray diffraction (XRD) and Raman spectroscopy. The electrical property of the investigated material was determined in terms of area-specific resistance (ASR). The chemical and electrical properties of 316L exposed to a dual environment of air/ (H2+H2O) were compared to those of 316L exposed to a single environment of air/air.

  7. Tensile Properties, Ferrite Contents, and Specimen Heating of Stainless Steels in Cryogenic Gas Tests

    NASA Astrophysics Data System (ADS)

    Ogata, T.; Yuri, T.; Ono, Y.

    2006-03-01

    We performed tensile tests at cryogenic temperatures below 77 K and in helium gas environment for SUS 304L and SUS 316L in order to obtain basic data of mechanical properties of the materials for liquid hydrogen tank service. We evaluate tensile curves, tensile properties, ferrite contents, mode of deformation and/or fracture, and specimen heating during the testing at 4 to 77 K. For both SUS 304L and 316L, tensile strength shows a small peak around 10 K, and specimen heating decreases above 30 K. The volume fraction of α-phase increases continuously up to 70 % with plastic strain, at approximately 15 % plastic strain for 304L and up to 35 % for 316L. There was almost no clear influence of testing temperature on strain-induced martensitic transformation at the cryogenic temperatures.

  8. Comparative MRI compatibility of 316 L stainless steel alloy and nickel-titanium alloy stents.

    PubMed

    Holton, Andrea; Walsh, Edward; Anayiotos, Andreas; Pohost, Gerald; Venugopalan, Ramakrishna

    2002-01-01

    The initial success of coronary stenting is leading to a proliferation in peripheral stenting. A significant portion of the stents used in a clinical setting are made of 316 low carbon stainless steel (SS). Other alloys that have been used for stent manufacture include tantalum, MP35N, and nickel-titanium (NiTi). The ferromagnetic properties of SS cause the production of artifacts in magnetic resonance imaging (MRI). The NiTi alloys, in addition to being known for their shape memory or superelastic properties, have been shown to exhibit reduced interference in MRI. Thus, the objective of this study was to determine the comparative MRI compatibility of SS and NiTi stents. Both gradient echo and spin-echo images were obtained at 1.5 and 4.1 T field strengths. The imaging of stents of identical geometry but differing compositions permitted the quantification of artifacts produced due to device composition by normalizing the radio frequency shielding effects. These images were analyzed for magnitude and spatial extent of signal loss within the lumen and outside the stent. B1 mapping was used to quantify the attenuation throughout the image. The SS stent caused significant signal loss and did not allow for visibility of the lumen. However, the NiTi stent caused only minor artifacting and even allowed for visualization of the signal from within the lumen. In addition, adjustments to the flip angle of standard imaging protocols were shown to improve the quality of signal from within the lumen. PMID:12549230

  9. Effect of Filler Metals on the Weldability and Mechanical Properties of Multi-pass PCGTA Weldments of AISI 316L

    NASA Astrophysics Data System (ADS)

    Devendranath Ramkumar, K.; Maruthi Mohan Reddy, P.; Raja Arjun, B.; Choudhary, Ayush; Srivastava, Anubhav; Arivazhagan, N.

    2015-04-01

    The influence of filler metals on the microstructure, mechanical properties, and corrosion behavior of AISI 316L welds was investigated. Pulsed current gas tungsten arc welding was employed to join the AISI 316L plates using two different fillers ER2553 and ERNiCr-3. Microstructures studies showed the presence of different forms of austenite on employing ER2553 filler and formation of migrated grain boundaries at the weld zone while using ERNiCr-3 filler. Tensile studies corroborated that the tensile strength was greater for the weldments employing ER2553 filler. Charpy V-notch studies ascertained that the impact toughness was greater for ER2553 weldments as compared to the parent metal. Potentiodynamic polarization curves clearly inferred that the weld zone of ER2553 exhibited better corrosion resistance among the various coupons tested. It was concluded from the study that ER2553 exhibited better mechanical and corrosion properties and could be adopted to achieve optimal properties compared to over-alloyed filler.

  10. Improving the Adhesion Resistance of the Boride Coatings to AISI 316L Steel Substrate by Diffusion Annealing

    NASA Astrophysics Data System (ADS)

    Campos-Silva, I.; Bernabé-Molina, S.; Bravo-Bárcenas, D.; Martínez-Trinidad, J.; Rodríguez-Castro, G.; Meneses-Amador, A.

    2016-07-01

    In this study, new results about the practical adhesion resistance of boride coating/substrate system formed at the surface of AISI 316 L steel and improved by means of a diffusion annealing process are presented. First, the boriding of AISI 316 L steel was performed by the powder-pack method at 1173 K with different exposure times (4-8 h). The diffusion annealing process was conducted on the borided steels at 1273 K with 2 h of exposure using a diluent atmosphere of boron powder mixture. The mechanical behavior of the boride coating/substrate system developed by both treatments was established using Vickers and Berkovich tests along the depth of the boride coatings, respectively. Finally, for the entire set of experimental conditions, the scratch tests were performed with a continuously increasing normal force, in which the practical adhesion resistance of the boride coating/substrate system was represented by the critical load. The failure mechanisms developed over the surface of the scratch tracks were analyzed; the FeB-Fe2B/substrate system exhibited an adhesive mode, while the Fe2B/substrate system obtained by the diffusion annealing process showed predominantly a cohesive failure mode.

  11. HYDROGEN EFFECTS ON FRACTURE TOUGHNESS OF TYPE 316L STAINLESS STEEL FROM 175 K TO 425 K

    SciTech Connect

    Morgan, M; Glenn Chapman, G

    2009-05-04

    The effects of hydrogen on the fracture-toughness properties of Type 316L stainless steel from 175 K to 425 K were measured. Fracture-toughness samples were fabricated from Type 316L stainless steel forgings and hydrogen-charged with hydrogen at 34 MPa and 623 K for two weeks prior to testing. The effect of hydrogen on the J-Integral vs. crack extension behavior was measured at various temperatures by fracturing non-charged and hydrogen-charged samples in an environmental chamber. Hydrogen-charged steels had lower toughness values than non-charged ones, but still retained good toughness properties. The fracture-toughness values of hydrogen-charged samples tested near ambient temperature were about 70% of non-charged values. For hydrogen-charged samples tested at 225 K and 425 K, the fracture-toughness values were 50% of the non-charged values. In all cases, fracture occurred by microvoid nucleation and coalescence, although the hydrogen-charged samples had smaller and more closely spaced microvoids. The results suggest that hydrogen effects on toughness are greater at 225 K than they are at ambient temperature because of strain-induced martensite formation. At 425 K, the hydrogen effects on toughness are greater than they are at ambient temperature because of the higher mobility of hydrogen.

  12. Liquid Metal Corrosion of 316L Stainless Steel, 410 Stainless Steel, and 1015 Carbon Steel in a Molten Zinc Bath

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Bright, Mark A.; Liu, Xingbo; Barbero, Ever

    2007-11-01

    Corrosion tests of 1015 low-carbon steel and two stainless steels (410 and 316L) were conducted in a pure zinc bath (99.98 wt pct Zn) in order to better understand the reaction mechanisms that occur during the degradation of submerged hardware at industrial general (batch) galvanizing operations. Through this testing, it was found that, in general, 316L stainless steel showed the best dissolution resistance among these three alloys, while 1015 carbon steel provided a lower solubility than 410 stainless steel. Investigating the failure mechanisms, both metallurgical composition and lattice structure played important roles in the molten metal corrosion behaviors of these alloys. High contents of nickel combined with the influence of chromium improved the resistance to molten zinc corrosion. Moreover, a face-centered-cubic (fcc) structure was more corrosion resistant than body-centered-cubic (bcc) possibly due to the compactness of the atomic structure. Analogously, the body-centered-tetragonal (bct) martensite lattice structure possessed enhanced susceptibility to zinc corrosion as a result of the greater atomic spacing and high strain energy. Finally, an increased bath temperature played an important role in molten metal corrosion by accelerating the dissolution process and changing the nature of intermetallic layers.

  13. Effect of Zr, Nb and Ti addition on injection molded 316L stainless steel for bio-applications: Mechanical, electrochemical and biocompatibility properties.

    PubMed

    Gulsoy, H Ozkan; Pazarlioglu, Serdar; Gulsoy, Nagihan; Gundede, Busra; Mutlu, Ozal

    2015-11-01

    The research investigated the effect of Zr, Nb and Ti additions on mechanical, electrochemical properties and biocompatibility of injection molded 316L stainless steel. Addition of elemental powder is promoted to get high performance of sintered 316L stainless steels. The amount of additive powder plays a role in determining the sintered microstructure and all properties. In this study, 316L stainless steel powders used with the elemental Zr, Nb and Ti powders. A feedstock containing 62.5 wt% powders loading was molded at different injection molded temperature. The binders were completely removed from molded components by solvent and thermal debinding at different temperatures. The debinded samples were sintered at 1350°C for 60 min. Mechanical, electrochemical property and biocompatibility of the sintered samples were performed mechanical, electrochemical, SBF immersion tests and cell culture experiments. Results of study showed that sintered 316L and 316L with additives samples exhibited high corrosion properties and biocompatibility in a physiological environment. PMID:26275484

  14. A Comparative Evaluation of the Effect of Low Cycle Fatigue and Creep-Fatigue Interaction on Surface Morphology and Tensile Properties of 316L(N) Stainless Steel

    NASA Astrophysics Data System (ADS)

    Mariappan, K.; Shankar, Vani; Sandhya, R.; Bhaduri, A. K.; Laha, Kinkar

    2016-04-01

    In the present work, the deformation and damage evolution in 316L(N) stainless steel during low cycle fatigue (LCF) and creep-fatigue interaction (CFI) loadings have been compared by evaluating the residual tensile properties. Towards this, LCF and CFI experiments were carried out at constant strain amplitude of ±0.6 pct, strain rate of 3 × 10-3 s-1 and temperature of 873 K (600 °C). During CFI tests, 30 minutes hold period was introduced at peak tensile strain. Experiments were interrupted up to various levels of fatigue life viz. 5, 10, 30, 50, and 60 pct of the total fatigue life ( N f) under both LCF and CFI conditions. The specimens subjected to interrupted fatigue loadings were subsequently monotonically strained at the same strain rate and temperature up to fracture. Optical and scanning electron microscopy and profilometry were conducted on the untested and tested samples to elucidate the damage evolution during the fatigue cycling under both LCF and CFI conditions. The yield strength (YS) increased sharply with the progress of fatigue damage and attained saturation within 10 pct of N f under LCF condition. On the contrary, under CFI loading condition, the YS continuously increased up to 50 pct of N f, with a sharp increase of YS up to 5 pct of N f followed by a more gradual increase up to 50 pct of N f. The difference in the evolution of remnant tensile properties was correlated with the synergistic effects of the underlying deformation and damage processes such as cyclic hardening/softening, oxidation, and creep. The evolution of tensile properties with prior fatigue damage has been correlated with the change in surface roughness and other surface features estimated by surface replica technique and fractography.

  15. Surface nanostructuring of Ni, Ti, and 316L stainless steel using ultrafast laser interactions

    NASA Astrophysics Data System (ADS)

    Gill, Matt; Perrie, Walter; Fox, Peter; O'Neill, William

    2005-04-01

    The generation of surface periodic structures (SPS) on laser machined surfaces is known to occur when exciting the surface near the ablation threshold using short pulse laser exposure. These effects were first observed in the late 1960s and have remained a laboratory curiosity. Although well studied at nanosecond timescales there have been limited number of studies at ultrafast timescales. We have investigated the conditions necessary to generate short and long-range periodic structures using ultrafast laser pulses at λ =775nm and 387 nm which may find application in the field of surface engineering. This work examines the formation of SPS on a range of materials including Ni, Ti and SS316 and their dependence on fluence and polarisation.

  16. The passivity of Type 316L stainless steel in borate buffer solution

    NASA Astrophysics Data System (ADS)

    Nicic, Igor; Macdonald, Digby D.

    2008-09-01

    The passivity of Type 316 SS in borate buffer solution (pH 8.35), in the steady-state, has been explored using a variety of electrochemical techniques, including potentiostatic polarization, Mott Schottky analysis, and electrochemical impedance spectroscopy. The study shows that the passive film is an n-type semiconductor with a donor density that is essentially independent of voltage across the passive state. The passive current density is also found to be voltage-independent, but the thickness of the barrier layer depends linearly on the applied voltage. These observations are consistent with the predictions of the Point Defect Model, noting that the point defects within the barrier layer of the passive film are metal interstitials or oxygen vacancies, or both. No evidence for p-type behavior was obtained, indicating that cation vacancies do not have a significant population density in the film compared with the two donors (cation interstitials and oxygen vacancies).

  17. Localized corrosion of 316L stainless steel with SiO2-CaO films obtained by means of sol-gel treatment.

    PubMed

    Vallet-Regí, M; Izquierdo-Barba, I; Gil, F J

    2003-11-01

    Sol-gel films on austenitic stainless steel (AISI 316L) polished wafer were prepared from sono-sols obtained from tetraethylorthosilane and hydrated calcium nitrate. However, pitting was observed in different places on the stainless steel surfaces. The corrosion resistance was evaluated by the polarization resistance in simulated body fluid environment at 37 degrees C. The critical current density, the passive current density, the corrosion potential, and the critical pitting potential were studied. The austenitic stainless steel 316L treated presents important electrochemical corrosion and consequently its application as endosseous implants is not possible. PMID:14566812

  18. The electrochemical behaviour of 316L austenitic stainless steel in Cl- containing environment under different H2S partial pressures

    NASA Astrophysics Data System (ADS)

    Ding, Jinhui; Zhang, Lei; Lu, Minxu; Wang, Jing; Wen, Zhibin; Hao, Wenhui

    2014-01-01

    In oil-gas production environments, presence of H2S-Cl- can induce deterioration of the passive film, leading to pitting corrosion of stainless steels. In this paper, by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and capacitance measurements (Mott-Schottky analysis), the electrochemical behaviour of AISI 316L austenitic stainless steel was investigated in Cl- solutions under different H2S partial pressures (from 0 to 1.0 bar). The results indicated that presence of H2S in Cl- solution can accelerate both the cathodic and anodic current density, leading to a metastable passive state in higher passive potential range, changing the semiconductor behaviour from p-type to n-type, increasing its susceptibility to corrosion. XPS analysis was employed to characterize the surface film after potentiostatic polarization, whose results provide good evidences for the electrochemical measurements.

  19. Preferred Crystallographic Orientation Development in Nano/Ultrafine-Grained 316L Stainless Steel During Martensite to Austenite Reversion

    NASA Astrophysics Data System (ADS)

    Eskandari, M.; Mohtadi-Bonab, M. A.; Basu, R.; Nezakat, M.; Kermanpur, A.; Szpunar, J. A.; Nahar, S.; Baghpanah, A. H.

    2015-02-01

    The crystallographic orientation of cold-rolled 316L stainless steel is investigated during reversion of strain-induced ά-martensite to nano/ultrafine-grained austenite upon annealing at 750 °C for different holding times; 1, 5, 15, and 30 min. The texture of nanoscale reverted austenite reveals a Brass ({110}<112>) and a Goss ({110}<100>) textures after annealing for 1 min. No new texture component is appeared through the completion of martensite to austenite reversion for 5 min, but the intensity of Brass and Goss textures are increased. Further annealing for 30 min results in a stronger texture with higher intensity for Brass compared to Goss.

  20. Characterization of hydroxyapatite coating by pulse laser deposition technique on stainless steel 316 L by varying laser energy

    NASA Astrophysics Data System (ADS)

    Khandelwal, Himanshu; Singh, Gurbhinder; Agrawal, Khelendra; Prakash, Satya; Agarwal, R. D.

    2013-01-01

    Hydroxyapatite is an attractive biomaterial mainly used in bone and tooth implants because it closely resembles human tooth and bone mineral and has proven to be biologically compatible with these tissues. In spite of this advantage of hydroxyapatite it has also certain limitation like inferior mechanical properties which do not make it suitable for long term load bearing applications; hence a lot of research is going on in the development of hydroxyapatite coating over various metallic implants. These metallic implants have good biocompatibility and mechanical properties. The aim of the present work is to deposit hydroxyapatite coating over stainless steel grade 316 L by pulse laser deposition technique by varying laser energy. To know the effect of this variation, the coatings were than characterized in detail by X-ray diffraction, finite emission-scanning electron microscope, atomic force microscope and energy dispersive X-ray spectroscopy.

  1. Dependence of the tensile properties of 316 L parent material and welds on implanted hydrogen and/or helium

    NASA Astrophysics Data System (ADS)

    Schroeder, Herbert; Liu, Wanpei

    1992-09-01

    The interest in the low temperature tensile properties of candidate alloys for first wall and blanket structures of future fusion devices is due to the possible low pressure water cooling and the associated low operation temperature in recent design studies. Therefore, the tensile properties of hydrogen and/or helium implanted 316 L stainless steel and its weldments as a function of gas concentrations and temperature were investigated. The main effects of the implantation are hardening, resulting in large increases of the yield strength proportional to the implanted gas concentration, and a gradual decrease of the corresponding rupture strain. The ultimate tensile stresses are less affected. The effect of helium implantation seems to be more pronounced than that of hydrogen implantation. At 673 K most of the implantation induced changes are recovered. Generally parent material and welds still show large ductility (≥20%) under all conditions investigated.

  2. Microstructural examination of the effect of surface machining on stress corrosion cracking in core shroud made of 316L

    SciTech Connect

    Sueishi, Y.; Kohyama, A.; Narui, M.; Asano, K.

    2006-07-01

    Cracks exhibited on the hardened surface region of the boiling water reactor (BWR) core shroud made of 316L were examined. The sample was removed from the circumference ring of a commercial power plant after about 9 years in service. On the surface with mechanical milling followed by grinding during the manufacturing process, micro-crack was found to propagate nearly perpendicular to the grinding direction. Cross-sectional transmission electron microscopy (TEM) observation of the micro-crack indicates that the crack has been initiated along the boundary of [111[<112> type deformation twins and the shear bands in Goss position [110]<001>. Along the crack wall, the Cr-Fe spinel and the grained magnetite were identified in inner and outer layer of the oxide thin film, respectively. The results suggest one potential mechanism of the cracking that the heavily deformed structure by surface machining is the origin or the factor for acceleration of the cracking. (authors)

  3. Corrosion resistance of multilayer hybrid sol-gel coatings deposited on the AISI 316L austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Caballero, Y. T.; Rondón, E. A.; Rueda, L.; Hernández Barrios, C. A.; Coy, A.; Viejo, F.

    2016-02-01

    In the present work multilayer hybrid sol-gel coatings were synthesized on the AISI 316L austenitic stainless steel employed in the fabrication of orthopaedic implants. Hybrid sols were obtained from a mixture of inorganic precursor, TEOS, and organic, GPTMS, using ethanol as solvent, and acetic acid as catalyst. The characterization of the sols was performed using pH measurements, rheological tests and infrared spectroscopy (FTIR) for different ageing times. On the other hand, the coatings were characterized by scanning electron microscopy (SEM), while the corrosion resistance was evaluated using anodic potentiodynamic polarization in SBF solution at 37±2°C. The results confirmed that sol-gel synthesis employing TEOS-GPTMS systems produces uniform and homogeneous coatings, which enhanced the corrosion resistance with regard to the parent alloy. Moreover, corrosion performance was retained after applying more than one layer (multilayer coatings).

  4. Compatibility study of 316L stainless steel bellows for XMC3690 reserve lithium/thionyl-chloride battery

    SciTech Connect

    Cieslak, W.R.; Delnick, F.M.; Crafts, C.C.

    1986-02-01

    Maintenance of the integrity of a battery's active electrochemical components throughout shelf life is essential to achieving acceptable performance characteristics. The electrolyte in the XMC3690 reserve lithium/thionyl-chloride (RLTC) battery is stored in a 316L stainless steel welded-bellows assembly. Corrosion of the bellows that might compromise battery performance must be avoided. Postmortem examination of welded bellows following electrolyte storage for 2 years, including up to 1 year at 70/sup 0/C, revealed no significant corrosion or any sign of stress-corrosion cracking. Transition metal ion concentrations in the electrolyte were very low and did not change with aging conditions. Based on these observations, we do not expect corrosion of the bellows assembly to limit shelf life of the XMC3690 RLTC battery.

  5. CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY (ETF) CHROME (VI) REDUCTANT SOLUTION USING 304 & 316L STAINLESS STEEL

    SciTech Connect

    DUNCAN, J.B.

    2007-06-27

    The Effluent Treatment Facility has developed a method to regenerate spent resin from the groundwater pump and treat intercepting chrome(VI) plumes (RPP-RPT-32207, Laboratory Study on Regeneration of Spent DOWEX 21K 16-20 Mesh Ion Exchange Resin). Subsequent laboratory studies have shown that the chrome(VI) may be reduced to chrome(III) by titrating with sodium metabisulfite to an oxidation reduction potential (ORP) of +280 mV at a pH of 2. This test plan describes the use of cyclic potentiodynamic polarization and linear polarization techniques to ascertain the electrochemical corrosion and pitting propensity of the 304 and 316L stainless steel in the acidified reducing the solution that will be contained in either the secondary waste receiver tank or concentrate tank.

  6. Galvanic couples of 316L steel with Ti and ion plated Ti and TiN coatings in Ringer's solutions.

    PubMed

    Gluszek, J; Jedrkowiak, J; Markowski, J; Masalski, J

    1990-07-01

    Steel 316L was coated with titanium or titanium nitride by ion plating. The tightness of the coatings was examined electro-chemically. The galvanic effects for the galvanic couples steel-titanium, steel-titanium-coated steel and steel-titanium nitride-coated steel were studied. It was found that both titanium and titanium nitride coatings were non-porous in Ringer's solution; titanium served as an anode in the couple steel-titanium; it was oxidized according to the logarithmic law. For the other two couples, the coatings were the cathodes. The rate of dissolution of steel in these couples, was however, smaller than expected, owing to a strong polarization of the coatings. The potential of the couple was similar to that of steel. PMID:2400799

  7. Laser surface alloying of 316L stainless steel coated with a bioactive hydroxyapatite-titanium oxide composite.

    PubMed

    Ghaith, El-Sayed; Hodgson, Simon; Sharp, Martin

    2015-02-01

    Laser surface alloying is a powerful technique for improving the mechanical and chemical properties of engineering components. In this study, laser surface irradiation process employed in the surface modification off 316L stainless steel substrate using hydroxyapatite-titanium oxide to provide a composite ceramic layer for the suitability of applying this technology to improve the biocompatibility of medical alloys and implants. Fusion of the metal surface incorporating hydroxyapatite-titania ceramic particles using a 30 W Nd:YAG laser at different laser powers, 40, 50 and 70% power and a scan speed of 40 mm s(-1) was observed to adopt the optimum condition of ceramic deposition. Coatings were evaluated in terms of microstructure, surface morphology, composition biocompatibility using XRD, ATR-FTIR, SEM and EDS. Evaluation of the in vitro bioactivity by soaking the treated metal in SBF for 10 days showed the deposition of biomimetic apatite. PMID:25636972

  8. Methodology for optimizing the electropolishing of stainless steel AISI 316L combining criteria of surface finish and dimensional precision

    NASA Astrophysics Data System (ADS)

    Núñez, P. J.; García-Plaza, E.; Martín, A. R.; Trujillo, R.; De la Cruz, C.

    2009-11-01

    This work examines a methodology for optimizing electrochemical polishing conditions bearing in mind the criteria that enhance minimum surface roughness and dimensional precision (minimum loss of thickness). The study consisted in electrochemically polishing stainless steel AISI 316L (ISO 4954 X2CrNiMo17133E) under a combination of different temperatures (T) baths and current densities (J), and application times (t). The surface finish (ΔRa) and dimensional variations (Δh) of the electrochemically polished workpieces were assessed, and the experimental data of the variables was correlated as can be seen by the response surfaces. This methodology enables optimum working areas to be specified using the sole criteria of surface finish, or by using a combination of both criteria (minimum roughness and maximum precision). The methodology has proven to be an optimum method for selecting electrochemical polishing conditions using the combined criteria of surface finish and dimensional precision in accordance with design requirements.

  9. Experimental investigations on effects of frequency in ultrasonically-assisted end-milling of AISI 316L: A feasibility study.

    PubMed

    Maurotto, A; Wickramarachchi, C T

    2016-02-01

    The effects of frequency in ultrasonic vibration assisted milling (UVAM) with axial vibration of the cutter is investigated in this paper. A series of face-mill experiment in dry conditions were conducted on AISI 316L, an alloy of widespread use in industry. The finished surfaces roughness were studied along with basic considerations on tool wear for both conventional milling and an array of frequencies for UVAM (20–40–60 kHz) in a wide range of cutting conditions. Surface residual stresses and cross-cut metallographic slides were used to investigate the hidden effects of UVAM. Experimental results showed competitive results for both surface roughness and residual stress in UVAM when compared with conventional milling especially in the low range of frequency with similar trend for tool wear. PMID:26601562

  10. The influence of nanostructured features on bacterial adhesion and bone cell functions on severely shot peened 316L stainless steel.

    PubMed

    Bagherifard, Sara; Hickey, Daniel J; de Luca, Alba C; Malheiro, Vera N; Markaki, Athina E; Guagliano, Mario; Webster, Thomas J

    2015-12-01

    Substrate grain structure and topography play major roles in mediating cell and bacteria activities. Severe plastic deformation techniques, known as efficient metal-forming and grain refining processes, provide the treated material with novel mechanical properties and can be adopted to modify nanoscale surface characteristics, possibly affecting interactions with the biological environment. This in vitro study evaluates the capability of severe shot peening, based on severe plastic deformation, to modulate the interactions of nanocrystallized metallic biomaterials with cells and bacteria. The treated 316L stainless steel surfaces were first investigated in terms of surface topography, grain size, hardness, wettability and residual stresses. The effects of the induced surface modifications were then separately studied in terms of cell morphology, adhesion and proliferation of primary human osteoblasts (bone forming cells) as well as the adhesion of multiple bacteria strains, specifically Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and ampicillin-resistant Escherichia coli. The results indicated a significant enhancement in surface work hardening and compressive residual stresses, maintenance of osteoblast adhesion and proliferation as well as a remarkable decrease in the adhesion and growth of gram-positive bacteria (S. aureus and S. epidermidis) compared to non-treated and conventionally shot peened samples. Impressively, the decrease in bacteria adhesion and growth was achieved without the use of antibiotics, for which bacteria can develop a resistance towards anyway. By slightly grinding the surface of severe shot peened samples to remove differences in nanoscale surface roughness, the effects of varying substrate grain size were separated from those of varying surface roughness. The expression of vinculin focal adhesions from osteoblasts was found to be singularly and inversely related to grain size, whereas the attachment of gram

  11. Electron Backscatter Diffraction Analysis of Joints Between AISI 316L Austenitic/UNS S32750 Dual-Phase Stainless Steel

    NASA Astrophysics Data System (ADS)

    Shamanian, Morteza; Mohammadnezhad, Mahyar; Amini, Mahdi; Zabolian, Azam; Szpunar, Jerzy A.

    2015-08-01

    Stainless steels are among the most economical and highly practicable materials widely used in industrial areas due to their mechanical and corrosion resistances. In this study, a dissimilar weld joint consisting of an AISI 316L austenitic stainless steel (ASS) and a UNS S32750 dual-phase stainless steel was obtained under optimized welding conditions by gas tungsten arc welding technique using AWS A5.4:ER2594 filler metal. The effect of welding on the evolution of the microstructure, crystallographic texture, and micro-hardness distribution was also studied. The weld metal (WM) was found to be dual-phased; the microstructure is obtained by a fully ferritic solidification mode followed by austenite precipitation at both ferrite boundaries and ferrite grains through solid-state transformation. It is found that welding process can affect the ferrite content and grain growth phenomenon. The strong textures were found in the base metals for both steels. The AISI 316L ASS texture is composed of strong cube component. In the UNS S32750 dual-phase stainless steel, an important difference between the two phases can be seen in the texture evolution. Austenite phase is composed of a major cube component, whereas the ferrite texture mainly contains a major rotated cube component. The texture of the ferrite is stronger than that of austenite. In the WM, Kurdjumov-Sachs crystallographic orientation relationship is found in the solidification microstructure. The analysis of the Kernel average misorientation distribution shows that the residual strain is more concentrated in the austenite phase than in the other phase. The welding resulted in a significant hardness increase in the WM compared to initial ASS.

  12. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-06-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  13. Improving the empirical model for plasma nitrided AISI 316L corrosion resistance based on Mössbauer spectroscopy

    NASA Astrophysics Data System (ADS)

    Campos, M.; de Souza, S. D.; de Souza, S.; Olzon-Dionysio, M.

    2011-11-01

    Traditional plasma nitriding treatments using temperatures ranging from approximately 650 to 730 K can improve wear, corrosion resistance and surface hardness on stainless steels. The nitrided layer consists of some iron nitrides: the cubic γ ' phase (Fe4N), the hexagonal phase ɛ (Fe2 - 3N) and a nitrogen supersatured solid phase γ N . An empirical model is proposed to explain the corrosion resistance of AISI 316L and ASTM F138 nitrided samples based on Mössbauer Spectroscopy results: the larger the ratio between ɛ and γ ' phase fractions of the sample, the better its resistance corrosion is. In this work, this model is examined using some new results of AISI 316L samples, nitrided under the same previous conditions of gas composition and temperature, but at different pressure, for 3, 4 and 5 h. The sample nitrided for 4 h, whose value for ɛ/ γ ' is maximum (= 0.73), shows a slightly better response than the other two samples, nitrided for 5 and 3 h ( ɛ/ γ ' = 0.72 and 0.59, respectively). Moreover, these samples show very similar behavior. Therefore, this set of samples was not suitable to test the empirical model. However, the comparison between the present results of potentiodynamic polarization curves and those obtained previously at 4 and 4.5 torr, could indicated that the corrosion resistance of the sample which only presents the γ N phase was the worst of them. Moreover, the empirical model seems not to be ready to explain the response to corrosion and it should be improved including the γ N phase.

  14. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    NASA Astrophysics Data System (ADS)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-08-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  15. The role of deformation mechanisms in flow localization of 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Wu, Xianglin; Pan, Xiao; Mabon, James C.; Li, Meimei; Stubbins, James F.

    2006-09-01

    Type 316 SS is widely used as a structural material in a variety of current accelerator driven systems and designs as well as in a number of current and advanced fission and fusion reactor concepts. The material is found to be very sensitive to irradiation damage in the temperature range of 150-400 °C, where low levels of irradiation exposure, as little as 0.1 dpa, can substantially reduce the uniform elongation in tensile tests. This process, where the plastic flow becomes highly localized resulting in very low overall ductility, is referred to as flow localization. The process controlling this restriction of flow is related to the difference between the yield and ultimate strengths such that dramatic irradiation-induced increases in the yield strength results in very limited plastic flow until necking. In this study, the temperature dependence of this process is examined in light of the operating deformation mechanisms. It is found that twinning is an important deformation mechanism at lower temperatures but is not available in the temperature range of concern since the stress to activate twinning becomes excessively high. This limits the deformation and leads to the flow localization process.

  16. Analysis of bi-layer oxide on austenitic stainless steel, 316L, exposed to Lead-Bismuth Eutectic (LBE) by X-ray Photoelectron Spectroscopy (XPS)

    NASA Astrophysics Data System (ADS)

    Koury, D.; Johnson, A. L.; Ho, T.; Farley, J. W.

    2013-09-01

    Corrosion of the austenitic stainless steel alloy 316L by Lead-Bismuth Eutectic (LBE) was studied using X-ray Photoelectron Spectroscopy (XPS) with Sputter-Depth Profiling (SDP), and compared to data taken by Scanning Electron Microscopy (SEM) and Energy Dispersive X-rays (EDXs). Exposed and unexposed samples were compared. Annealed 316L samples, exposed to LBE for durations of 1000, 2000 and 3000 h, developed bi-layer oxides up to 30 μm thick. Analysis of the charge-states of the 2p3/2 peaks of iron, chromium, and nickel in the oxide layers reveal an inner layer consisting of iron and chromium oxides (likely spinel-structured) and an outer layer consisting of iron oxides (Fe3O4). Cold-rolled 316L samples, exposed for the same durations, form a chromium-rich, thin (⩽1 μm) oxide with some oxidized iron in the outermost ˜200 nm of the oxide layer. This is the first experiment to investigate what components of the 316L are oxidized by LBE exposure. It is shown here that nickel is metallic in the inner layer.

  17. Effect of dissolved oxygen content on stress corrosion cracking of a cold worked 316L stainless steel in simulated pressurized water reactor primary water environment

    NASA Astrophysics Data System (ADS)

    Zhang, Litao; Wang, Jianqiu

    2014-03-01

    Stress corrosion crack growth tests of a cold worked nuclear grade 316L stainless steel were conducted in simulated pressurized water reactor (PWR) primary water environment containing various dissolved oxygen (DO) contents but no dissolved hydrogen. The crack growth rate (CGR) increased with increasing DO content in the simulated PWR primary water. The fracture surface exhibited typical intergranular stress corrosion cracking (IGSCC) characteristics.

  18. Microstructural characterization of an SA508–309L/308L–316L domestic dissimilar metal welded safe-end joint

    SciTech Connect

    Ming, Hongliang; Zhang, Zhiming; Wang, Jianqiu Han, En-Hou; Ke, Wei

    2014-11-15

    The microstructure of an SA508–309L/308L–316L domestic dissimilar metal welded safe-end joint was characterized in this work by optical microscopy, scanning electron microscopy (with electron back scattering diffraction) and micro-hardness testing. Epitaxial growth and competitive growth are evident in the 308L–316L fusion boundary regions. A martensite layer, carbon-depleted zones, and type-II and type-I boundaries are found in the SA508–309L fusion boundary regions, while only martensite and austenite mixed zones are observed in the SA508–308L fusion boundary regions. The microstructure near the fusion boundary and the microstructure transition in the SA508 heat affected zone are quite complex. Both for SA508–309L/308L and 308L–316L, the highest residual strain is located on the outside of the weldment. The residual strain and the grain boundary character distribution change with increasing distance from the fusion boundary in the heat affected zone of 316L. Micro-hardness measurements also reveal non-uniform mechanical properties across the weldment. - Highlights: • The microstructure of SA508 HAZ, especially near the FB, is very complex. • The outside of the dissimilar metal welded joint has the highest residual. • The micro-hardness distributions along the DMWJ are non-uniform.

  19. Influence of particle velocity and molten phase on the chemical and mechanical properties of HVOF-sprayed structural coatings of alloy 316L

    SciTech Connect

    Voggenreiter, H.; Huber, H.; Beyer, S.; Spies, H.J.

    1995-12-31

    The HP/HVOF spraying process allows the production of oxide-low, thick coatings with low porosity. This fact implies the feasibility of load-bearing HP/HVOF-sprayed structures. Optimum mechanical properties are required for structural applications of HP/HVOF-sprayed iron base alloy 316L. Process-parameter-dependent particle properties like temperature and velocity strongly influence the microstructure and the chemical and mechanical properties of HP/HVOF-sprayed alloy 316L. Results of metallographical and chemical analysis and laser-optic-aided particle velocity measurement lead to a new understanding of particle oxidation based on a high volume fraction of liquid phase and high particle impact velocity. The volume fraction of oxides greatly affects the mechanical properties of homogenized HP/HVOF-316 L. Optimum process parameters result in reduced oxide content less than 0.9% and consequently in strength and elongation comparable to that of wrought alloy 316L. Additionally to these excellent mechanical properties, a low porosity level of about 0.1 to 0.2% is achieved. These fundamental results were transferred successfully to a new type of combustion chamber for hypersonic aircraft with reduced complexity and weight.

  20. Biofilm initiation and growth of Pseudomonas aeruginosa on 316L stainless steel in low gravity in orbital space flight

    NASA Astrophysics Data System (ADS)

    Todd, Paul; Pierson, Duane L.; Allen, Britt; Silverstein, JoAnn

    The formation of biofilms by water microorganisms such as Pseudomonas aeruginosa in spacecraft water systems has been a matter of concern for long-duration space flight. Crewed spacecraft plumbing includes internal surfaces made of 316L stainless steel. Experiments were therefore undertaken to compare the ability of P. aeruginosa to grow in suspension, attach to stainless steel and to grow on stainless steel in low gravity on the space shuttle. Four categories of cultures were studied during two space shuttle flights (STS-69 and STS-77). Cultures on the ground were held in static horizontal or vertical cylindrical containers or were tumbled on a clinostat and activated under conditions identical to those for the flown cultures. The containers used on the ground and in flight were BioServe Space Technologies’ Fluid Processing Apparatus (FPA), an open-ended test tube with rubber septa that allows robotic addition of bacteria to culture media to initiate experiments and the addition of fixative to conclude experiments. Planktonic growth was monitored by spectrophotometry, and biofilms were characterized quantitatively by epifluorescence and scanning electron microscopy. In these experiments it was found that: (1) Planktonic growth in flown cultures was more extensive than in static cultures, as seen repeatedly in the history of space microbiology, and closely resembled the growth of tumbled cultures. (2) Conversely, the attachment of cells in flown cultures was as much as 8 times that in tumbled cultures but not significantly different from that in static horizontal and vertical cultures, consistent with the notion that flowing fluid reduces microbial attachment. (3) The final surface coverage in 8 days was the same for flown and static cultures but less by a factor of 15 in tumbled cultures, where coverage declined during the preceding 4 days. It is concluded that cell attachment to 316L stainless steel in the low gravity of orbital space flight is similar to that

  1. Effect of Strain Rate on the Dynamic Recrystallization Behavior in a Nitrogen-Enhanced 316L(N)

    NASA Astrophysics Data System (ADS)

    Mandal, Sumantra; Jayalakshmi, M.; Bhaduri, A. K.; Subramanya Sarma, V.

    2014-11-01

    In this paper, the effect of strain rate (in the domain of 0.001 to 10 s-1) on dynamic recrystallization (DRX) kinetics in a nitrogen-enhanced 316L(N) austenitic stainless steel during high temperature [≥1123 K (≥850 °C)] deformation is reported. In the low strain rate domain ( i.e., <0.1 s-1), the DRX is predominantly governed by higher growth of DRX grains resulting in a higher DRX fraction and larger DRX grain size. On the other hand, DRX at higher strain rates ( i.e., ≥1 s-1) is mainly controlled by higher nucleation resulting in higher DRX fraction with a finer grain size. In the intermediate strain rate regime of 0.1 s-1, sluggish kinetics of DRX is observed since neither the nucleation nor the growth of DRX grains is predominant. The annealing twinning event, which may accelerates the DRX kinetics, is also observed to occur more frequently during the low and high strain rate deformations.

  2. Effect of thermal treatment on the corrosion resistance of Type 316L stainless steel exposed in supercritical water

    NASA Astrophysics Data System (ADS)

    Jiao, Y.; Zheng, W.; Guzonas, D. A.; Cook, W. G.; Kish, J. R.

    2015-09-01

    There are still unknown aspects about the growth mechanism of oxide scales formed on candidate stainless steel fuel cladding materials during exposure in supercritical water (SCW) under the conditions relevant to the Canadian supercritical water-cooled reactor (SCWR). The tendency for intermetallic precipitates to form within the grains and on grain boundaries during prolonged exposure at high temperatures represents an unknown factor to corrosion resistance, since they tend to bind alloyed Cr. The objective of this study was to better understand the extent to which intermetallic precipitates affects the mode and extent of corrosion in SCW. Type 316L stainless steel, used as a model Fe-Cr-Ni-Mo alloy, was exposed to 25 MPa SCW at 550 °C for 500 h in a static autoclave for this purpose. Mechanically-abraded samples were tested in the mill-annealed (MA) and a thermally-treated (TT) condition. The thermal treatment was conducted at 815 °C for 1000 h to precipitate the carbide (M23C6), chi (χ), laves (η) and sigma (σ) phases. It was found that although relatively large intermetallic precipitates formed at the scale/alloy interface locally affected the oxide scale formation, their discontinuous formation did not affect the short-term overall apparent corrosion resistance.

  3. Stress corrosion cracking and corrosion fatigue on 316L stainless steel in boric acid concentrated media at 320 C

    SciTech Connect

    Herms, E.; Olive, J.M.; Puiggali, M.; Boursier, J.M.

    1999-07-01

    Stress Corrosion Cracking (SCC) and Corrosion-Fatigue (CF) tests were performed in autoclave at 320 C in concentrated boric acid chlorinated media in presence of oxygen or hydrogen on type 316L austenitic stainless steel. Crack Growth Rates (CGR) are higher in non deaerated solutions for both SCC and CF than in hydrogenated solutions. CGR are relatively similar in CF and in SCC, excepted for high load ratio in CF where CGR are higher than in SCC. Detailed analysis of the fracture surface shows some distinct features between SCC and CF. Intergranular and transgranular mode of fracture are observed on SCC and CF. Fracture modes depend on the chemistry of solution in SCC and on frequency in CF. Traces of slip bands and crack front marking associated with oxide scale present on fracture surfaces exist in SCC and CF. Fatigue striations appear for low load ratio and high frequency. Secondary intergranular and transgranular cracking is observed only on SCC fracture surfaces and ligament morphology can be different in SCC relative to FC.

  4. Optimization of Process Parameters of Hybrid Laser-Arc Welding onto 316L Using Ensemble of Metamodels

    NASA Astrophysics Data System (ADS)

    Zhou, Qi; Jiang, Ping; Shao, Xinyu; Gao, Zhongmei; Cao, Longchao; Yue, Chen; Li, Xiongbin

    2016-04-01

    Hybrid laser-arc welding (LAW) provides an effective way to overcome problems commonly encountered during either laser or arc welding such as brittle phase formation, cracking, and porosity. The process parameters of LAW have significant effects on the bead profile and hence the quality of joint. This paper proposes an optimization methodology by combining non-dominated sorting genetic algorithm (NSGA-II) and ensemble of metamodels (EMs) to address multi-objective process parameter optimization in LAW onto 316L. Firstly, Taguchi experimental design is adopted to generate the experimental samples. Secondly, the relationships between process parameters (i.e., laser power (P), welding current (A), distance between laser and arc (D), and welding speed (V)) and the bead geometries are fitted using EMs. The comparative results show that the EMs can take advantage of the prediction ability of each stand-alone metamodel and thus decrease the risk of adopting inappropriate metamodels. Then, the NSGA-II is used to facilitate design space exploration. Besides, the main effects and contribution rates of process parameters on bead profile are analyzed. Eventually, the verification experiments of the obtained optima are carried out and compared with the un-optimized weld seam for bead geometries, weld appearances, and welding defects. Results illustrate that the proposed hybrid approach exhibits great capability of improving welding quality in LAW.

  5. The Effect of Post-Heat Treatment on Microstructure of 316L Cold-Sprayed Coatings and Their Corrosion Performance

    NASA Astrophysics Data System (ADS)

    Dikici, B.; Yilmazer, H.; Ozdemir, I.; Isik, M.

    2016-04-01

    The combined effects of process gases and post-heat treatment temperature on the microstructure of 316L cold-sprayed coatings on Al5052 substrates have been investigated in this study. The stainless steel coatings were subjected to heat treatment at four different temperatures (250, 500, 750, and 1000 °C) to study the effect of heat treatment. In addition, the corrosion performances of the coatings at different process temperatures have been compared using the potentiodynamic scanning technique. Microstructural characterization of the coatings was carried out using scanning and transmission electron microscopy and x-ray diffraction. The results of present study showed that cold-sprayed stainless steel coatings processed with helium exhibited higher corrosion resistance than those of coatings sprayed with nitrogen process gas. This could partially be attributed to the reduction in porosity level (4.9%) and improvement of particle-particle bonding. In addition, evaluation of the mechanical and microstructural properties of the coatings demonstrated that subsequent heat treatment has major influence on the deposited layers sprayed with He process gas.

  6. Effect of SUS316L stainless steel surface conditions on the wetting of molten multi-component oxides ceramic

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Matsuda, Nozomu; Shinozaki, Nobuya; Miyoshi, Noriko; Shiraishi, Takanobu

    2015-02-01

    A study on the effect of SUS316L stainless steel surface conditions on the wetting behavior of molten multi-component oxides ceramic was performed and aimed to contribute to the further understanding of the application of oxides ceramic in penetration treatment of stainless steel coatings and the deposition of stainless steel cermet coatings. The results show that at 1273 K, different surface pre-treatments (polishing and heating) had an important effect on the wetting behavior. The molten multi-component oxides showed good wettability on both stainless steel substrates, however, the wetting process on the polished substrate was significantly slower than that on the heated substrates. The mechanism of the interfacial reactions was discussed based on the microscopic and thermodynamic analysis, the substrates reacted with oxygen generated from the decomposition of the molten multi-component oxides and oxygen contained in the argon atmosphere, and the oxide film caused the molten multi-component oxides ceramic to spread on the substrates surfaces. For the polished substrate, more time was required for the surface oxidation to reach the surface composition of Heated-S, which resulted in relatively slow spreading and wetting rates. Moreover, the variance of the surface roughness drove the final contact angles to slightly different values following the sequence Polished-S > Heated-S.

  7. In situ monitoring the pulse CO 2 laser interaction with 316-L stainless steel using acoustical signals and plasma analysis

    NASA Astrophysics Data System (ADS)

    Khosroshahi, M. E.; pour, F. Anoosheh; Hadavi, M.; Mahmoodi, M.

    2010-10-01

    In most laser material processing, material removal by different mechanisms is involved. Here, application of acoustic signals with thermoelastic (below threshold) and breakdown origin (above threshold) together with plasma plume analysis as a simple monitoring system of interaction process is suggested. In this research the interaction of pulse CO 2 laser with 200 ns duration and maximum energy of 1.3 J operating at 1 Hz with austenitic stainless steel (316-L) is reported. The results showed that the non-linear point of the curve can serve as a useful indicator of melting fluence threshold (in this case ≈830 J cm -2) with corresponding temperature calculated using plasma plume analysis. Higher acoustic amplitudes and larger plasma plume volume indicates more intense interaction. Also, analysis showed that a phase explosion process with material removal (ejecta) in the form of non-adiabatic (i.e., dt ≫ α-1) is at play after laser pulse is ended. Also, SEM photographs show different surface quality medication at different laser intensities, which indicates the importance of recoil momentum pressure and possibly electrons and ions densities in heat transfer. Finally, electrochemical test indicate an improved corrosion resistance for laser treated samples compared to untreated ones.

  8. Biocompatibility studies of low temperature nitrided and collagen-I coated AISI 316L austenitic stainless steel.

    PubMed

    Martinesi, M; Stio, M; Treves, C; Borgioli, F

    2013-06-01

    The biocompatibility of austenitic stainless steels can be improved by means of surface engineering techniques. In the present research it was investigated if low temperature nitrided AISI 316L austenitic stainless steel may be a suitable substrate for bioactive protein coating consisting of collagen-I. The biocompatibility of surface modified alloy was studied using as experimental model endothelial cells (human umbilical vein endothelial cells) in culture. Low temperature nitriding produces modified surface layers consisting mainly of S phase, the supersaturated interstitial solid solution of nitrogen in the austenite lattice, which allows to enhance surface microhardness and corrosion resistance in PBS solution. The nitriding treatment seems to promote the coating with collagen-I, without chemical coupling agents, in respect of the untreated alloy. For biocompatibility studies, proliferation, lactate dehydrogenase levels and secretion of two metalloproteinases (MMP-2 and MMP-9) were determined. Experimental results suggest that the collagen protection may be favourable for endothelial cell proliferation and for the control of MMP-2 release. PMID:23471501

  9. MC3T3-E1 cell response to stainless steel 316L with different surface treatments.

    PubMed

    Zhang, Hongyu; Han, Jianmin; Sun, Yulong; Huang, Yongling; Zhou, Ming

    2015-11-01

    In the present study, stainless steel 316L samples with polishing, aluminum oxide blasting, and hydroxyapatite (HA) coating were prepared and characterized through a scanning electron microscope (SEM), optical interferometer (surface roughness, Sq), contact angle, surface composition and phase composition analyses. Osteoblast-like MC3T3-E1 cell adhesion on the samples was investigated by cell morphology using a SEM (4h, 1d, 3d, 7d), and cell proliferation was assessed by MTT method at 1d, 3d, and 7d. In addition, adsorption of bovine serum albumin on the samples was evaluated at 1h. The polished sample was smooth (Sq: 1.8nm), and the blasted and HA coated samples were much rougher (Sq: 3.2μm and 7.8μm). Within 1d of incubation, the HA coated samples showed the best cell morphology (e.g., flattened shape and complete spread), but there was no significant difference after 3d and 7d of incubation for all the samples. The absorbance value for the HA coated samples was the highest after 1d and 3d of incubation, indicating better cell viability. However, it reduced to the lowest value at 7d. Protein adsorption on the HA coated samples was the highest at 1h. The results indicate that rough stainless steel surface improves cell adhesion and morphology, and HA coating contributes to superior cell adhesion, but inhibits cell proliferation. PMID:26249561

  10. Femtosecond laser treatment of 316L improves its surface nanoroughness and carbon content and promotes osseointegration: An in vitro evaluation.

    PubMed

    Kenar, Halime; Akman, Erhan; Kacar, Elif; Demir, Arif; Park, Haiwoong; Abdul-Khaliq, Hashim; Aktas, Cenk; Karaoz, Erdal

    2013-08-01

    Cell-material surface interaction plays a critical role in osseointegration of prosthetic implants used in orthopedic surgeries and dentistry. Different technical approaches exist to improve surface properties of such implants either by coating or by modification of their topography. Femtosecond laser treatment was used in this study to generate microspotted lines separated by 75, 125, or 175μm wide nanostructured interlines on stainless steel (316L) plates. The hydrophobicity and carbon content of the metallic surface were improved simultaneously through this method. In vitro testing of the laser treated plates revealed a significant improvement in adhesion of human endothelial cells and human bone marrow mesenchymal stem cells (hBM MSCs), the cells involved in microvessel and bone formation, respectively, and a significant decrease in fibroblast adhesion, which is implicated in osteolysis and aseptic loosening of prostheses. The hBM MSCs showed an increased bone formation rate on the laser treated plates under osteogenic conditions; the highest mineral deposition was obtained on the surface with 125μm interline distance (292±18mg/cm(2) vs. 228±43mg/cm(2) on untreated surface). Further in vivo testing of these laser treated surfaces in the native prosthetic implant niche would give a real insight into their effectiveness in improving osseointegration and their potential use in clinical applications. PMID:23563298

  11. Electrochemical and In Vitro Behavior of Nanostructure Sol-Gel Coated 316L Stainless Steel Incorporated with Rosemary Extract

    NASA Astrophysics Data System (ADS)

    Motalebi, Abolfazl; Nasr-Esfahani, Mojtaba

    2013-06-01

    The corrosion resistance of AISI 316L stainless steel for biomedical applications, was significantly enhanced by means of hybrid organic-inorganic sol-gel thin films deposited by spin-coating. Thin films of less than 100 nm with different hybrid characters were obtained by incorporating rosemary extract as green corrosion inhibitor. The morphology, composition, and adhesion of hybrid sol-gel coatings have been examined by SEM, EDX, and pull-off test, respectively. Addition of high additive concentrations (0.1%) did not disorganize the sol-gel network. Direct pull-off test recorded a mean coating-substrate bonding strength larger than 21.2 MPa for the hybrid sol-gel coating. The effect of rosemary extract, with various added concentrations from 0.012 to 0.1%, on the anticorrosion properties of sol-gel films have been characterized by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests in simulated body fluid (SBF) solution and has been compared to the bare metal. Rosemary extract additions (0.05%) have significantly increased the corrosion protection of the sol-gel thin film to higher than 90%. The in vitro bioactivity of prepared films indicates that hydroxyapatite nuclei can form and grow on the surface of the doped sol-gel thin films. The present study shows that due to their excellent anticorrosion properties, bioactivity and bonding strength to substrate, doped sol-gel thin films are practical hybrid films in biomedical applications.

  12. Summary of recommended correlations for ITER-grade type 316L(N) for the ITER materials properties handbook

    SciTech Connect

    Billone, M.C.; Pawel, J.E.

    1996-04-01

    The focus of this effort is the effects of irradiation on the ultimate tensile strengths (UTS), the yield strength (YS), the uniform elongation (UE), the total elongation (TE) and the reduction in area (RA) in the ITER-relevant temperature range of 100-400{degrees}C. For the purpose of this summary, data for European heats of 316 with 0.020.08 wt.% are referred to as E316L(N) data and grouped together. Other heats of 316 and Ti-modified 316 are also included in the data base. For irradiation and postirradiation-test temperatures in the range of 200-400{degrees}C, the common behavior of these heats of stainless steel is a yield strength approaching the ultimate tensile strength approaching 800 MPa, a uniform elongation approaching 0.3%, a total elongation approaching 3-9%, and a high (about 60%) reduction in area as the neutron damage approaches 10 dpa.

  13. Electrochemical characterization of AISI 316L stainless steel in contact with simulated body fluid under infection conditions.

    PubMed

    López, Danián Alejandro; Durán, Alicia; Ceré, Silvia Marcela

    2008-05-01

    Titanium and cobalt alloys, as well as some stainless steels, are among the most frequently used materials in orthopaedic surgery. In industrialized countries, stainless steel devices are used only for temporary implants due to their lower corrosion resistance in physiologic media when compared to other alloys. However, due to economical reasons, the use of stainless steel alloys for permanent implants is very common in developing countries. The implantation of foreign bodies is sometimes necessary in the modern medical practice. However, the complex interactions between the host and the can implant weaken the local immune system, increasing the risk of infections. Therefore, it is necessary to further study these materials as well as the characteristics of the superficial film formed in physiologic media in infection conditions in order to control their potential toxicity due to the release of metallic ions in the human body. This work presents a study of the superficial composition and the corrosion resistance of AISI 316L stainless steel and the influence of its main alloying elements when they are exposed to an acidic solution that simulates the change of pH that occurs when an infection develops. Aerated simulated body fluid (SBF) was employed as working solution at 37 degrees C. The pH was adjusted to 7.25 and 4 in order to reproduce normal body and disease state respectively. Corrosion resistance was measured by means of electrochemical impedance spectroscopy (EIS) and anodic polarization curves. PMID:17999036

  14. TEM study of the nucleation of bubbles induced by He implantation in 316L industrial austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Jublot-Leclerc, S.; Lescoat, M.-L.; Fortuna, F.; Legras, L.; Li, X.; Gentils, A.

    2015-11-01

    10 keV He ions were implanted in-situ in a TEM into thin foils of 316L industrial austenitic stainless steel at temperatures ranging from 200 to 550 °C. As a result, overpressurized nanometric bubbles are created with density and size depending strongly on both the temperature and fluence of implantation. An investigation on their nucleation and growth is reported through a rigorous statistical analysis whose procedure, including the consideration of free surface effects, is detailed. In the parameter range considered, the results show that an increase of fluence promotes both the nucleation and growth of the bubbles whilst an increase of temperature enhances the growth of the bubbles at the expense of their nucleation. The confrontation of resulting activation energies with existing models for bubble nucleation enables the identification of the underlying mechanisms. In spite of slight differences resulting from different conditions of implantation among which the He concentration, He production rate and He/dpa ratio, it appears that the dominating mechanisms are the same as those obtained in metals in previous studies, which, in addition to corroborating literature results, shows the suitability of in-situ TEM experiments to simulate the production of helium in nuclear materials.

  15. The Effect of Surface Finish on Low-Temperature Acetylene-Based Carburization of 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Ge, Yindong; Ernst, Frank; Kahn, Harold; Heuer, Arthur H.

    2014-12-01

    We observed a strong influence of surface finish on the efficacy of low-temperature acetylene-based carburization of AISI 316L austenitic stainless steel. Steel coupons were prepared with different surface finishes prior to carburization, from P400 SiC grit paper to 1- µm-diameter-diamond-paste. The samples with the finer surface finish developed a thicker "case" (a carbon-rich hardened surface layer) and a larger surface carbon concentration. Transmission electron microscopy revealed that the differences arose mainly from the nature of the deformation-induced disturbed layer on the steel surface. A thick (>400 nm) disturbed layer consisting of nano-crystalline grains (≈10 nm diameter) inhibits acetylene-based carburization. The experimental observations can be explained by assuming that during machining or coarse polishing, the surface oxide layer is broken up and becomes incorporated into the deformation-induced disturbed layer. The incorporated oxide-rich films retard or completely prevent the ingress of carbon into the stainless steel.

  16. Study on cerium-doped nano-TiO2 coatings for corrosion protection of 316 L stainless steel

    NASA Astrophysics Data System (ADS)

    Li, Suning; Wang, Qian; Chen, Tao; Zhou, Zhihua; Wang, Ying; Fu, Jiajun

    2012-04-01

    Many methods have been reported on improving the photogenerated cathodic protection of nano-TiO2 coatings for metals. In this work, nano-TiO2 coatings doped with cerium nitrate have been developed by sol-gel method for corrosion protection of 316 L stainless steel. Surface morphology, structure, and properties of the prepared coatings were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The corrosion protection performance of the prepared coatings was evaluated in 3 wt% NaCl solution by using electrochemical techniques in the presence and absence of simulated sunlight illumination. The results indicated that the 1.2% Ce-TiO2 coating with three layers exhibited an excellent photogenerated cathodic protection under illumination attributed to the higher separation efficiency of electron-hole pairs and higher photoelectric conversion efficiency. The results also showed that after doping with an appropriate concentration of cerium nitrate, the anti-corrosion performance of the TiO2 coating was improved even without irradiation due to the self-healing property of cerium ions.

  17. Optimization of Process Parameters of Hybrid Laser-Arc Welding onto 316L Using Ensemble of Metamodels

    NASA Astrophysics Data System (ADS)

    Zhou, Qi; Jiang, Ping; Shao, Xinyu; Gao, Zhongmei; Cao, Longchao; Yue, Chen; Li, Xiongbin

    2016-08-01

    Hybrid laser-arc welding (LAW) provides an effective way to overcome problems commonly encountered during either laser or arc welding such as brittle phase formation, cracking, and porosity. The process parameters of LAW have significant effects on the bead profile and hence the quality of joint. This paper proposes an optimization methodology by combining non-dominated sorting genetic algorithm (NSGA-II) and ensemble of metamodels (EMs) to address multi-objective process parameter optimization in LAW onto 316L. Firstly, Taguchi experimental design is adopted to generate the experimental samples. Secondly, the relationships between process parameters ( i.e., laser power ( P), welding current ( A), distance between laser and arc ( D), and welding speed ( V)) and the bead geometries are fitted using EMs. The comparative results show that the EMs can take advantage of the prediction ability of each stand-alone metamodel and thus decrease the risk of adopting inappropriate metamodels. Then, the NSGA-II is used to facilitate design space exploration. Besides, the main effects and contribution rates of process parameters on bead profile are analyzed. Eventually, the verification experiments of the obtained optima are carried out and compared with the un-optimized weld seam for bead geometries, weld appearances, and welding defects. Results illustrate that the proposed hybrid approach exhibits great capability of improving welding quality in LAW.

  18. Microstructural Development and Technical Challenges in Laser Additive Manufacturing: Case Study with a 316L Industrial Part

    NASA Astrophysics Data System (ADS)

    Marya, Manuel; Singh, Virendra; Marya, Surendar; Hascoet, Jean Yves

    2015-08-01

    Additive manufacturing (AM) brings disruptive changes to the ways parts, and products are designed, fabricated, tested, qualified, inspected, marketed, and sold. These changes introduce novel technical challenges and concerns arising from the maturity and diversity of today's AM processes, feedstock materials, and process parameter interactions. AM bears a resemblance with laser and electron beam welding in the so-called conduction mode, which involves a multitude of dynamic physical events between the projected feedstock and a moving heat source that eventually influence AM part properties. For this paper, an air vent was selected for its thin-walled, hollow, and variable cross section, and limited size. The studied air vents, randomly selected from a qualification batch, were fabricated out of 316L stainless steel using a 4 kW fiber laser powder-fed AM system, referred to as construction laser additive direct (CLAD). These were systematically characterized by microhardness indentation, visual examination, optical and scanning electron microscopy, and electron-back-scattering diffraction in order to determine AM part suitability for service and also broadly discuss metallurgical phenomena. The paper then briefly expands the discussion to include additional engineering alloys and further analyze relationships between AM process parameters and AM part properties, consistently utilizing past experience with the same powder-fed CLAD 3D printer, the well-established science and technology of welding and joining, and recent publications on additive manufacturing.

  19. Surface interactions of a W-DLC-coated biomedical AISI 316L stainless steel in physiological solution.

    PubMed

    Antunes, Renato A; de Lima, Nelson Batista; Rizzutto, Márcia de Almeida; Higa, Olga Zazuco; Saiki, Mitiko; Costa, Isolda

    2013-04-01

    The corrosion stability of a W-DLC coated surgical AISI 316L stainless steel in Hanks' solution has been evaluated. Particle induced X-ray emission (PIXE) measurements were performed to evaluate the incorporation of potentially bioactive elements from the physiological solution. The film structure was analyzed by X-ray diffractometry and micro-Raman spectroscopy. The wear behavior was assessed using the sphere-on-disc geometry. The in vitro biocompatibility of the W-DLC film was evaluated by cytotoxicity tests. The corrosion resistance of the stainless steel substrate decreased in the presence of the PVD layer. EIS measurements suggest that this behavior was closely related to the corrosion attack through the coating pores. PIXE measurements revealed the presence of Ca and P in the W-DLC film after immersion in Hanks' solution. This result shows that the PIXE technique can be applied to identify and evaluate the incorporation of bioactive elements by W-DLC films. The film showed good wear resistance and biocompatibility. PMID:23371768

  20. Electrochemical Behavior of CrN Coated on 316L Stainless Steel in Simulated Cathodic Environment of Proton Exchange Membrane Fuel Cell

    NASA Astrophysics Data System (ADS)

    Nam, Nguyen Dang; Kim, Jung-Gu

    2008-08-01

    Four types of CrN coating were deposited on type 316L stainless steel by magnetron sputtering physical vapor deposition (PVD) for use in bipolar plates. Four samples deposited at various bias voltages were evaluated under potentiodynamic, potentiostatic, and electrochemical impedance spectroscopy (EIS) conditions. EIS data were monitored for 96 h in an aerated corrosive environment at 70 °C to determine coating performance at +600 mV application. The electrochemical behavior of the coatings was enhanced with decreasing bias voltage. The CrN films on the 316L stainless steel substrate exhibited high protective efficiency, that is, increasing corrosion resistance with decreasing bias voltage. X-ray diffraction (XRD) analysis confirmed the formation of crystalline-refined CrN(200) at a low bias voltage.

  1. In vitro response of human peripheral blood mononuclear cells to AISI 316L austenitic stainless steel subjected to nitriding and collagen coating treatments.

    PubMed

    Stio, Maria; Martinesi, Maria; Treves, Cristina; Borgioli, Francesca

    2015-02-01

    Surface modification treatments can be used to improve the biocompatibility of austenitic stainless steels. In the present research two different modifications of AISI 316L stainless steel were considered, low temperature nitriding and collagen-I coating, applied as single treatment or in conjunction. Low temperature nitriding produced modified surface layers consisting mainly of S phase, which enhanced corrosion resistance in PBS solution. Biocompatibility was assessed using human peripheral blood mononuclear cells (PBMC) in culture. Proliferation, lactate dehydrogenase (LDH) levels, release of cytokines (TNF-α, IL-1β, IL-12, IL-10), secretion of metalloproteinase (MMP)-9 and its inhibitor TIMP-1, and the gelatinolytic activity of MMP-9 were determined. While the 48-h incubation of PBMC with all the sample types did not negatively influence cell proliferation, LDH and MMP-9 levels, suggesting therefore a good biocompatibility, the release of the pro-inflammatory cytokines was always remarkable when compared to that of control cells. However, in the presence of the nitrided and collagen coated samples, the release of the pro-inflammatory cytokine IL-1β decreased, while that of the anti-inflammatory cytokine IL-10 increased, in comparison with the untreated AISI 316L samples. Our results suggest that some biological parameters were ameliorated by these surface treatments of AISI 316L. PMID:25655502

  2. Effect of Surface Condition and Heat Treatment on Corrosion of Type 316L Stainless Steel in a Mercury Thermal Convection Loop

    SciTech Connect

    Pawel, S J

    2001-09-25

    Two thermal convection loops (TCLs) fabricated from 316L stainless steel and containing mercury and a variety of 316L coupons representing variable surface conditions and heat treatments have been operated continuously for 2000 h. Surface conditions included surface ground, polished, gold-coated, chemically etched, bombarded with Fe to simulate radiation damage, and oxidized. Heat treatments included solution treated, welded, and sensitized. In addition, a nitrogen doped 316L material, termed 316LN, was also examined in the solution treated condition. Duplicate TCLs were operated in this experiment--both were operated with a 305 C peak temperature, a 65 C temperature gradient, and mercury velocity of 1.2 m/min--but only one included a 36 h soak in Hg at 310 C just prior to operation to encourage wetting. Results indicate that the soak in Hg at 310 C had no lasting effect on wetting or compatibility with Hg. Further, based on examination of post-test wetting and coupon weight loss, only the gold-coated surfaces revealed significant interaction with Hg. In areas wetted significantly by Hg, the extreme surface of the stainless steel (ca 10 {micro}m) was depleted in Ni and Cr compared to the bulk composition.

  3. Effect of Surface Condition and Heat Treatment on Corrosion of Type 316L Stainless Steel in a Mercury Thermal Convection Loop

    SciTech Connect

    Pawel, S.J.

    2000-10-17

    Two thermal convection loops (TCLs) fabricated from 316L stainless steel and containing mercury and a variety of 316L coupons representing variable surface conditions and heat treatments have been operated continuously for 2000 h. Surface conditions included surface ground, polished, gold-coated, chemically etched, bombarded with Fe to simulate radiation damage, and oxidized. Heat treatments included solution treated, welded, and sensitized. In addition, a nitrogen doped 316L material, termed 316LN, was also examined in the solution treated condition. Duplicate TCLs were operated in this experiment--both were operated with a 305 C peak temperature, a 65 C temperature gradient, and mercury velocity of 1.2 m/min--but only one included a 36 h soak in Hg at 310 C just prior to operation to encourage wetting. Results indicate that the soak in Hg at 310 C had no lasting effect on wetting or compatibility with Hg. Further, based on examination of post-test wetting and coupon weight loss, only the gold-coated surfaces revealed significant interaction with Hg. In areas wetted significantly by Hg, the extreme surface of the stainless steel (ca 10 {micro}m) was depleted in Ni and Cr compared to the bulk composition.

  4. EBSD and TEM investigation of the hot deformation substructure characteristics of a type 316L austenitic stainless steel.

    PubMed

    Cizek, P; Whiteman, J A; Rainforth, W M; Beynon, J H

    2004-03-01

    The evolution of crystallographic texture and deformation substructure was studied in a type 316L austenitic stainless steel, deformed in rolling at 900 degrees C to true strain levels of about 0.3 and 0.7. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were used in the investigation and a comparison of the substructural characteristics obtained by these techniques was made. At the lower strain level, the deformation substructure observed by EBSD appeared to be rather poorly developed. There was considerable evidence of a rotation of the pre-existing twin boundaries from their original orientation relationship, as well as the formation of highly distorted grain boundary regions. In TEM, at this strain level, the substructure was more clearly revealed, although it appeared rather inhomogeneously developed from grain to grain. The subgrains were frequently elongated and their boundaries often approximated to traces of [111] slip planes. The corresponding misorientations were small and largely displayed a non-cumulative character. At the larger strain, the substructure within most grains became well developed and the corresponding misorientations increased. This resulted in better detection of sub-boundaries by EBSD, although the percentage of indexing slightly decreased. TEM revealed splitting of some sub-boundaries to form fine microbands, as well as the localized formation of microshear bands. The substructural characteristics observed by EBSD, in particular at the larger strain, generally appeared to compare well with those obtained using TEM. With increased strain level, the mean subgrain size became finer, the corresponding mean misorientation angle increased and both these characteristics became less dependent on a particular grain orientation. The statistically representative data obtained will assist in the development of physically based models of microstructural evolution during thermomechanical processing of austenitic

  5. Influence of the Carbo-Chromization Process on the Microstructural, Hardness, and Corrosion Properties of 316L Sintered Stainless Steel

    NASA Astrophysics Data System (ADS)

    Iorga, Sorin; Cojocaru, Mihai; Chivu, Adriana; Ciuca, Sorin; Burdusel, Mihail; Badica, Petre; Leuvrey, Cédric; Schmerber, Guy; Ulhaq-Bouillet, Corinne; Colis, Silviu

    2014-06-01

    We report on the changes on the microstructural, hardness, and corrosion properties induced by carbo-chromization of 316L stainless steel prepared by Spark Plasma Sintering technique. The thermo-chemical treatments have been performed using pack cementation. The carburizing and chromization were carried out between 1153 K (880 °C)/4 h to 1253 K (980 °C)/12 h and 1223 K (950 °C)/6 h to 1273 K (1000 °C)/12 h in a solid powder mixture of charcoal/BaCO3 and ferrochromium/alumina/NH4Cl, respectively. The obtained layers were investigated using X-ray and electron diffraction, optical and scanning electron microscopies, Vickers micro-hardness, and potentiodynamic measurements. The thickness of the carbo-chromized layer ranges between 300 and 500 μm. Besides the host γ-phase, the layers are mainly constituted of carbides (Fe7C3, Cr23C6, Cr7C3, and Fe3C) and traces of α'-martensite. The average hardness values decrease smoothly from 650 HV at the sample surface down to 200 HV at the center of the sample. The potentiodynamic tests revealed that the carbo-chromized samples have smaller corrosion resistance with respect to the untreated material. For strong chromization regimes, the corrosion rate is increased by a factor of four with respect to that of the untreated material, while the micro-hardness of the layer is three times larger. Such materials are suited to be used in environments where good corrosion resistance and wear properties are required.

  6. Evaluation of the soft tissue biocompatibility of MgCa0.8 and surgical steel 316L in vivo: a comparative study in rabbits

    PubMed Central

    2010-01-01

    Background Recent studies have shown the potential suitability of magnesium alloys as biodegradable implants. The aim of the present study was to compare the soft tissue biocompatibility of MgCa0.8 and commonly used surgical steel in vivo. Methods A biodegradable magnesium calcium alloy (MgCa0.8) and surgical steel (S316L), as a control, were investigated. Screws of identical geometrical conformation were implanted into the tibiae of 40 rabbits for a postoperative follow up of two, four, six and eight weeks. The tibialis cranialis muscle was in direct vicinity of the screw head and thus embedded in paraffin and histologically and immunohistochemically assessed. Haematoxylin and eosin staining was performed to identify macrophages, giant cells and heterophil granulocytes as well as the extent of tissue fibrosis and necrosis. Mouse anti-CD79α and rat anti-CD3 monoclonal primary antibodies were used for B- and T-lymphocyte detection. Evaluation of all sections was performed by applying a semi-quantitative score. Results Clinically, both implant materials were tolerated well. Histology revealed that a layer of fibrous tissue had formed between implant and overlying muscle in MgCa0.8 and S316L, which was demarcated by a layer of synoviocyte-like cells at its interface to the implant. In MgCa0.8 implants cavities were detected within the fibrous tissue, which were surrounded by the same kind of cell type. The thickness of the fibrous layer and the amount of tissue necrosis and cellular infiltrations gradually decreased in S316L. In contrast, a decrease could only be noted in the first weeks of implantation in MgCa0.8, whereas parameters were increasing again at the end of the observation period. B-lymphocytes were found more often in MgCa0.8 indicating humoral immunity and the presence of soluble antigens. Conversely, S316L displayed a higher quantity of T-lymphocytes. Conclusions Moderate inflammation was detected in both implant materials and resolved to a minimum

  7. Influence of microstructure on the corrosion resistance of AISI type 304L and type 316L sintered stainless steels exposed to ferric chloride solution

    SciTech Connect

    Otero, E.; Pardo, A.; Utrilla, M.V.; Perez, F.J.; Saenz, E.

    1995-10-01

    The corrosion behavior of type 304L and type 316L austenitic stainless steels, produced by powder metallurgy, when exposed to a ferric chloride solution was studied. The exposures were conducted according to ASTM G48-76, Method A. The influence of ferric chloride concentration and exposure temperature on the corrosion kinetics of these materials was evaluated. A mechanism is proposed to explain the associated morphology observed in the microstructures produced after exposure of these P/M alloys to the aggressive medium.

  8. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment

    PubMed Central

    Ruiz, A.; Timke, T.; van de Sande, A.; Heftrich, T.; Novotny, R.; Austin, T.

    2016-01-01

    This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. PMID:27158647

  9. Laser surface texturing of 316L stainless steel in air and water: A method for increasing hydrophilicity via direct creation of microstructures

    NASA Astrophysics Data System (ADS)

    Razi, Sepehr; Madanipour, Khosro; Mollabashi, Mahmoud

    2016-06-01

    Laser processing of materials in water contact is sometimes employed for improving the machining, cutting or welding quality. Here, we demonstrate surface patterning of stainless steel grade 316L by nano-second laser processing in air and water. Suitable adjustments of laser parameters offer a variety of surface patterns on the treated targets. Furthermore alterations of different surface features such as surface chemistry and wettability are investigated in various processing circumstances. More than surface morphology, remarkable differences are observed in the surface oxygen content and wettability of the samples treated in air and water at the same laser processing conditions. Mechanisms of the changes are discussed extensively.

  10. Corrosion and microstructural analysis data for AISI 316L and AISI 347H stainless steels after exposure to a supercritical water environment.

    PubMed

    Ruiz, A; Timke, T; van de Sande, A; Heftrich, T; Novotny, R; Austin, T

    2016-06-01

    This article presents corrosion data and microstructural analysis data of austenitic stainless steels AISI 316L and AISI 347H exposed to supercritical water (25 MPa, 550 °C) with 2000 ppb of dissolved oxygen. The corrosion tests lasted a total of 1200 h but were interrupted at 600 h to allow measurements to be made. The microstructural data have been collected in the grain interior and at grain boundaries of the bulk of the materials and at the superficial oxide layer developed during the corrosion exposure. PMID:27158647

  11. Specimen shipment

    USGS Publications Warehouse

    Franson, J. Christian

    1987-01-01

    Procedures for shipping specimens vary with different disease diagnostic laboratories. Therefore, it is important to contact the receiving laboratory and obtain specific instructions. This will facilitate processing of specimens when they reach the laboratory and assure that the quality of the specimens is not compromised. Time spent on field investigation, specimen collection, and obtaining an adequate history will be of little clue is specimens become contaminated, decomposed, or otherwise spoiled enroute to the diagnostic laboratory. There are five bases of proper specimen shipment: (1) prevent cross-contamination from specimen to specimen, (2) prevent decomposition of the specimen, (3) prevent leakage of fluids, (4) preserve individual specimen identity, and (5) properly label the package. Basic supplies needed for specimen shipment are shown in Fig. 3.1.

  12. Cultures and co-cultures of human blood mononuclear cells and endothelial cells for the biocompatibility assessment of surface modified AISI 316L austenitic stainless steel.

    PubMed

    Stio, Maria; Martinesi, Maria; Treves, Cristina; Borgioli, Francesca

    2016-12-01

    Samples of AISI 316L austenitic stainless steel were subjected either to grinding and polishing procedure, or to grinding and then low temperature glow-discharge nitriding treatment, or to grinding, nitriding and subsequently coating with collagen-I. Nitrided samples, even if only ground, show a higher corrosion resistance in PBS solution, in comparison with ground and polished AISI 316L. Biocompatibility was evaluated in vitro by incubating the samples with either peripheral blood mononuclear cells (PBMC) or human umbilical vein endothelial cells (HUVEC), tested separately or in co-culture. HUVEC-PBMC co-culture and co-incubation of HUVEC with PBMC culture medium, after the previous incubation of PBMC with metallic samples, allowed to determine whether the incubation of PBMC with the different samples might affect HUVEC behaviour. Many biological parameters were considered: cell proliferation, release of cytokines, matrix metalloproteinases (MMPs) and sICAM-1, gelatinolytic activity of MMPs, and ICAM-1 protein expression. Nitriding treatment, with or without collagen coating of the samples, is able to ameliorate some of the biological parameters taken into account. The obtained results point out that biocompatibility may be successfully tested in vitro, using cultures of normal human cells, as blood and endothelial cells, but more than one cell line should be used, separately or in co-culture, and different parameters should be determined, in particular those correlated with inflammatory phenomena. PMID:27612806

  13. Effect of Heat Treatment on Low Temperature Toughness of Reduced Pressure Electron Beam Weld Metal of Type 316L Stainless Steel

    NASA Astrophysics Data System (ADS)

    Nakagawa, H.; Fujii, H.; Tamura, M.

    2006-03-01

    Austenitic stainless steels are considered to be the candidate materials for liquid hydrogen vessels and the related equipments, and those welding parts that require high toughness at cryogenic temperature. The authors have found that the weld metal of Type 316L stainless steel processed by reduced pressure electron beam (RPEB) welding has high toughness at cryogenic temperature, which is considered to be due to the single-pass welding process without reheating effect accompanied by multi-pass welding process. In this work, the effect of heat treatment on low temperature toughness of the RPEB weld metal of Type 316L was investigated by Charpy impact test at 77K. The absorbed energy decreased with higher temperature and longer holding time of heat treatment. The remarkable drop in the absorbed energy was found with heat treatment at 1073K for 2 hours, which is as low as that of conventional multi-pass weld metal such as tungsten inert gas welding. The observations of fracture surface and microstructure revealed that the decrease in the absorbed energy with heat treatment resulted from the precipitation of intermetallic compounds near delta-ferrite phase.

  14. Effect of Oxygen Content Upon the Microstructural and Mechanical Properties of Type 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

    NASA Astrophysics Data System (ADS)

    Cooper, Adam J.; Cooper, Norman I.; Dhers, Jean; Sherry, Andrew H.

    2016-09-01

    Although hot isostatic pressing (HIP) has been shown to demonstrate significant advances over more conventional manufacture routes, it is important to appreciate and quantify the detrimental effects of oxygen involvement during the HIP manufacture process on the microstructural and material properties of the resulting component. This paper quantifies the effects of oxygen content on the microstructure and Charpy impact properties of HIP'd austenitic stainless steel, through combination of detailed metallographic examination and mechanical testing on HIP'd Type 316L steel containing different concentrations (100 to 190 ppm) of oxygen. Micron-scale pores were visible in the microstructure of the HIP'd materials postmetallographic preparation, which result from the removal of nonmetallic oxide inclusions during metallographic preparation. The area fraction of the resulting pores is shown to correlate with the oxygen concentration which influences the Charpy impact toughness over the temperature range of 77 K to 573 K (-196 °C to 300 °C), and demonstrates the influence of oxygen involved during the HIP manufacture process on Charpy toughness. The same test procedures and microstructural analyses were performed on commercially available forged 316L. This showed comparatively fewer inclusions and exhibited higher Charpy impact toughness over the tested temperature range.

  15. Effect of Heat Treatment on Low Temperature Toughness of Reduced Pressure Electron Beam Weld Metal of Type 316L Stainless Steel

    SciTech Connect

    Nakagawa, H.; Fujii, H.; Tamura, M.

    2006-03-31

    Austenitic stainless steels are considered to be the candidate materials for liquid hydrogen vessels and the related equipments, and those welding parts that require high toughness at cryogenic temperature. The authors have found that the weld metal of Type 316L stainless steel processed by reduced pressure electron beam (RPEB) welding has high toughness at cryogenic temperature, which is considered to be due to the single-pass welding process without reheating effect accompanied by multi-pass welding process.In this work, the effect of heat treatment on low temperature toughness of the RPEB weld metal of Type 316L was investigated by Charpy impact test at 77K. The absorbed energy decreased with higher temperature and longer holding time of heat treatment. The remarkable drop in the absorbed energy was found with heat treatment at 1073K for 2 hours, which is as low as that of conventional multi-pass weld metal such as tungsten inert gas welding. The observations of fracture surface and microstructure revealed that the decrease in the absorbed energy with heat treatment resulted from the precipitation of intermetallic compounds near delta-ferrite phase.

  16. Ion Beam Analysis, structure and corrosion studies of nc-TiN/a-Si3N4 nanocomposite coatings deposited by sputtering on AISI 316L

    NASA Astrophysics Data System (ADS)

    García, J.; Canto, C. E.; Flores, M.; Andrade, E.; Rodríguez, E.; Jiménez, O.; Solis, C.; de Lucio, O. G.; Rocha, M. F.

    2014-07-01

    In this work, nanocomposite coatings of nc-TiN/a-Si3N4, were deposited on AISI 316L stainless steel substrate by a DC and RF reactive magnetron co-sputtering technique using an A-N2 plasma. The structure of the coatings was characterized by means of XRD (X-ray Diffraction). The substrate and coating corrosion resistance were evaluated by potentiodynamic polarization using a Ringer solution as electrolyte. Corrosion tests were conducted with the purpose to evaluate the potential of this coating to be used on biomedical alloys. IBA (Ion Beam Analysis) techniques were applied to measure the elemental composition profiles of the films and, XPS (X-ray Photoelectron Spectroscopy) were used as a complementary technique to obtain information about the compounds present in the films. The nanocomposite coatings of nc-TiN/a-Si3N4 show crystalline (TiN) and amorphous (Si3N4) phases which confer a better protection against the corrosion effects compared with that of the AISI 316L.

  17. Effect of Oxygen Content Upon the Microstructural and Mechanical Properties of Type 316L Austenitic Stainless Steel Manufactured by Hot Isostatic Pressing

    NASA Astrophysics Data System (ADS)

    Cooper, Adam J.; Cooper, Norman I.; Dhers, Jean; Sherry, Andrew H.

    2016-06-01

    Although hot isostatic pressing (HIP) has been shown to demonstrate significant advances over more conventional manufacture routes, it is important to appreciate and quantify the detrimental effects of oxygen involvement during the HIP manufacture process on the microstructural and material properties of the resulting component. This paper quantifies the effects of oxygen content on the microstructure and Charpy impact properties of HIP'd austenitic stainless steel, through combination of detailed metallographic examination and mechanical testing on HIP'd Type 316L steel containing different concentrations (100 to 190 ppm) of oxygen. Micron-scale pores were visible in the microstructure of the HIP'd materials postmetallographic preparation, which result from the removal of nonmetallic oxide inclusions during metallographic preparation. The area fraction of the resulting pores is shown to correlate with the oxygen concentration which influences the Charpy impact toughness over the temperature range of 77 K to 573 K (-196 °C to 300 °C), and demonstrates the influence of oxygen involved during the HIP manufacture process on Charpy toughness. The same test procedures and microstructural analyses were performed on commercially available forged 316L. This showed comparatively fewer inclusions and exhibited higher Charpy impact toughness over the tested temperature range.

  18. Effect of Annealing Temperature on Microstructure and Mechanical Properties of Bulk 316L Stainless Steel with Nano- and Micro-crystalline Dual Phases

    NASA Astrophysics Data System (ADS)

    La, Peiqing; Wei, Fuan; Lu, Xuefeng; Chu, Chenggang; Wei, Yupeng; Wang, Hongding

    2014-10-01

    Microstructures and mechanical properties of 316L stainless steels with dual phases austenite prepared by an aluminothermic reaction casting were explored. It is found that the steels consist of nano- and micro-crystalline austenite phases, a little δ ferrite and contaminations. Before and after annealing at 1073 K and 1273 K (800 °C and 1000 °C), average grain sizes of the nanocrystalline austenite phase are about 32, 31, 38 nm, respectively. Tensile strength increases first from 371 to 640 MPa and then decreases to 454 MPa. However, elongation ratio increases gradually from 16 to 23 and then 31 pct after annealing. The results illustrate that the steel after annealing at 1073 K (800 °C) has better properties, also indicating that combination of dual nano- and micro-crystalline austenite phase is conductive to improving tensile properties of materials.

  19. Evaluation of the Effect of Dynamic Sodium on the Low Cycle Fatigue Properties of 316L(N) Stainless Steel Base and Weld Joints

    NASA Astrophysics Data System (ADS)

    Ganesan, V.; Kannan, R.; Mariappan, K.; Sukumaran, G.; Sandhya, R.; Rao, K. Bhanu Sankara

    2012-06-01

    Low cycle fatigue (LCF) tests on 316L(N) austenitic stainless steel base and weld joints were at 823 K and 873 K at a constant strain rate of 3 × 10 -3 s -1 with strain ranges varying from {±}0.4% to {±}1.0% in a servo-hydraulic fatigue test system under flowing sodium environment. The cyclic stress response exhibited a similar trend as that in air comprising of an initial rapid hardening, followed by a slight softening stage before saturation. The fatigue lives are significantly improved in sodium environment when compared to identical testing conditions in air environment. The lack of oxidation in sodium environment is attributed to the delayed crack initiation, reduced crack propagation rate and consequent increase in fatigue life. Comparison of the data evaluated in sodium with RCC-MR design code, derived on the basis of data obtained from air shows that the design based on air tests is conservative.

  20. Erosion-corrosion resistance of electroplated Co-Pd film on 316L stainless steel in a hot sulfuric acid slurry environment

    NASA Astrophysics Data System (ADS)

    Li, Sirui; Zuo, Yu; Ju, Pengfei

    2015-03-01

    A Co-Pd film was deposited on 316L stainless steel by electroplating. The erosion-corrosion behavior of the Co-Pd plated samples in hot sulfuric acid solution with SiO2 particles was investigated. The results showed that there was a significant synergistic effect between erosion and corrosion. At higher stirring speed, even in such strong corrosive environment the erosion-corrosion rate of Co-Pd plated samples was controlled mainly by the erosion resistance. The erosion-corrosion resistance of pure Pd plated sample decreased rapidly with increasing stirring speed, whereas that of Co-Pd plated sample kept almost stable under the tested conditions due to the high micro-hardness and good corrosion resistance of the film.

  1. Corrosion behavior of TiN, TiAlN, TiAlSiN-coated 316L stainless steel in simulated proton exchange membrane fuel cell environment

    NASA Astrophysics Data System (ADS)

    Nam, Nguyen Dang; Vaka, Mahesh; Tran Hung, Nguyen

    2014-12-01

    To gain high hardness, good thermal stability and corrosion resistance, multicomponent TiAlSiN coating has been developed using different deposition methods. In this study, the influence of Al and Si on the electrochemical properties of TiN-coated 316L stainless steel as bipolar plate (BP) materials has been investigated in simulated proton exchange membrane fuel cell environment. The deposited TiN, TiAlN and TiAlSiN possess high hardness of 23.9, 31.7, 35.0 GPa, respectively. The coating performance of the TiN coating is enhanced by Al and Si addition due to lower corrosion current density and higher Rcoating and Rct values. This result could be attributed to the formation of crystalline-refined TiN(200), which improves the surface roughness, surface resistance, corrosion performance, and decreased passive current density.

  2. Electropolishing of Re-melted SLM Stainless Steel 316L Parts Using Deep Eutectic Solvents: 3 × 3 Full Factorial Design

    NASA Astrophysics Data System (ADS)

    Alrbaey, K.; Wimpenny, D. I.; Al-Barzinjy, A. A.; Moroz, A.

    2016-07-01

    This three-level three-factor full factorial study describes the effects of electropolishing using deep eutectic solvents on the surface roughness of re-melted 316L stainless steel samples produced by the selective laser melting (SLM) powder bed fusion additive manufacturing method. An improvement in the surface finish of re-melted stainless steel 316L parts was achieved by optimizing the processing parameters for a relatively environmentally friendly (`green') electropolishing process using a Choline Chloride ionic electrolyte. The results show that further improvement of the response value-average surface roughness ( Ra) can be obtained by electropolishing after re-melting to yield a 75% improvement compared to the as-built Ra. The best Ra value was less than 0.5 μm, obtained with a potential of 4 V, maintained for 30 min at 40 °C. Electropolishing has been shown to be effective at removing the residual oxide film formed during the re-melting process. The material dissolution during the process is not homogenous and is directed preferentially toward the iron and nickel, leaving the surface rich in chromium with potentially enhanced properties. The re-melted and polished surface of the samples gave an approximately 20% improvement in fatigue life at low stresses (approximately 570 MPa). The results of the study demonstrate that a combination of re-melting and electropolishing provides a flexible method for surface texture improvement which is capable of delivering a significant improvement in surface finish while holding the dimensional accuracy of parts within an acceptable range.

  3. Electropolishing of Re-melted SLM Stainless Steel 316L Parts Using Deep Eutectic Solvents: 3 × 3 Full Factorial Design

    NASA Astrophysics Data System (ADS)

    Alrbaey, K.; Wimpenny, D. I.; Al-Barzinjy, A. A.; Moroz, A.

    2016-05-01

    This three-level three-factor full factorial study describes the effects of electropolishing using deep eutectic solvents on the surface roughness of re-melted 316L stainless steel samples produced by the selective laser melting (SLM) powder bed fusion additive manufacturing method. An improvement in the surface finish of re-melted stainless steel 316L parts was achieved by optimizing the processing parameters for a relatively environmentally friendly (`green') electropolishing process using a Choline Chloride ionic electrolyte. The results show that further improvement of the response value-average surface roughness (Ra) can be obtained by electropolishing after re-melting to yield a 75% improvement compared to the as-built Ra. The best Ra value was less than 0.5 μm, obtained with a potential of 4 V, maintained for 30 min at 40 °C. Electropolishing has been shown to be effective at removing the residual oxide film formed during the re-melting process. The material dissolution during the process is not homogenous and is directed preferentially toward the iron and nickel, leaving the surface rich in chromium with potentially enhanced properties. The re-melted and polished surface of the samples gave an approximately 20% improvement in fatigue life at low stresses (approximately 570 MPa). The results of the study demonstrate that a combination of re-melting and electropolishing provides a flexible method for surface texture improvement which is capable of delivering a significant improvement in surface finish while holding the dimensional accuracy of parts within an acceptable range.

  4. SU-E-T-548: Modeling of Breast IORT Using the Xoft 50 KV Brachytherapy Source and 316L Steel Rigid Shield

    SciTech Connect

    Burnside, W

    2015-06-15

    Purpose: Xoft provides a set of 316L Stainless Steel Rigid Shields to be used with their 50 kV X-ray source for Breast IORT treatments. Modeling the different shield sizes in MCNP provides information to help make clinical decisions for selecting the appropriate shield size. Methods: The Xoft Axxent 50 kV Electronic Brachytherapy System has several applications in radiation therapy, one of which is treating cancer of the breast intraoperatively by placing the miniaturized X-ray tube inside an applicator balloon that is expanded to fill the lumpectomy bed immediately following tumor removal. The ribs, lung, and muscular chest wall are all regions at risk to receive undesired dose during the treatment. A Xoft 316L Stainless Steel Rigid Shield can be placed between the intracostal muscles of the chest wall and the remaining breast tissue near the balloon to attenuate the beam and protect these organs. These shields are provided in 5 different sizes, and the effects on dose to the surrounding tissues vary with shield size. MCNP was used to model this environment and tally dose rate to certain regions of interest. Results: The average rib dose rate calculated using 0cm (i.e., no shield), 3cm, and 5cm diameter shields were 26.89, 15.43, and 8.91 Gy/hr respectively. The maximum dose rates within the rib reached 94.74 Gy/hr, 53.56 Gy/hr, and 31.44 Gy/hr for the 0cm, 3cm, and 5cm cases respectively. The shadowing effect caused by the steel shields was seen in the 3-D meshes and line profiles. Conclusion: This model predicts a higher dose rate to the underlying rib region with the 3cm shield compared to the 5cm shield; it may be useful to select the largest possible diameter when choosing a shield size for a particular IORT patient. The ability to attenuate the beam to reduce rib dose was also confirmed. Research sponsored by Xoft Inc, a subsidiary of iCAD.

  5. Characterization of the mechanism of bi-layer oxide growth on austenitic stainless steels 316L and D9 in oxygen-controlled Lead-Bismuth Eutectic (LBE)

    NASA Astrophysics Data System (ADS)

    Koury, Daniel

    Lead Bismuth Eutectic (LBE) has been proposed for use in programs for accelerator-based and reactor-based transmutation of nuclear waste. LBE is a leading candidate material as a spallation target (in accelerator-based transmutation) and an option for the sub-critical blanket coolant. The corrosion by LBE of annealed and cold-rolled 316L stainless steels, and the modified austenitic stainless steel alloy D9, has been studied using Scanning Electron Microscopy (SEM), Electron Probe Micro Analysis (EPMA), and X-ray Photoelectron Spectroscopy (XPS). Exposed and unexposed samples have been compared and the differences studied. Small amounts of surface contamination are present on the samples and have been removed by ion-beam sputtering. The unexposed samples reveal typical stainless steel characteristics: a chromium oxide passivation surface layer and metallic iron and nickel. The exposed samples show protective iron oxide and chromium oxide growths on the surface. Oxygen takes many forms on the exposed samples, including oxides of iron and chromium, carbonates, and organic acids from subsequent handling after exposure to LBE. Different types of surface preparation have lead to considerably different modes of corrosion. The cold-rold samples were resistant to thick oxide growth, having only a thin (< 1 mum), dense chromium-rich oxide. The annealed 316L and D9 samples developed thick, bi-layered oxides, the inner layer consisting of chromium-rich oxides (likely spinel) and the outer layer consisting mostly of iron oxides. The cold-rolled samples were able to maintain a thin chromium oxide layer because of the surface work performed on it, as ample diffusion pathways provided an adequate supply of chromium atoms. The annealed samples grew thick oxides because iron was the primary diffusant, as there are fewer fast-diffusion pathways and therefore an amount of chromium insufficient to maintain a chromium based oxide. Even the thick oxide, however, can prolong the life of

  6. Ball Indentation Studies on the Effect of Nitrogen on the Tensile Properties of 316LN SS

    NASA Astrophysics Data System (ADS)

    Mathew, M. D.; Ganesh Kumar, J.; Ganesan, V.; Laha, K.

    2015-12-01

    Type 316L(N) stainless steel (SS) containing 0.02-0.03 wt% carbon and 0.06-0.08 wt% nitrogen is used as the major structural material for the components of fast reactors. Research is underway to improve the high-temperature mechanical properties of 316LN SS by increasing the nitrogen content in the steel above the level of 0.08 wt%. In this investigation, ball indentation (BI) technique was used to evaluate the effect of nitrogen content on the tensile properties of 316LN SS. BI tests were conducted on four different heats of 316LN SS containing 0.07, 0.11, 0.14 and 0.22 wt% nitrogen in the temperature range 300-923 K. The tensile properties such as yield strength and ultimate tensile strength increased with increase in nitrogen content at all the investigated temperatures. These results were consistent with the corresponding uniaxial tensile test results. These studies showed that BI technique can be used to optimize the chemical composition during alloy development by evaluating tensile properties with minimum volume of material.

  7. Interfacial characterization of SLM parts in multi-material processing: Metallurgical diffusion between 316L stainless steel and C18400 copper alloy

    SciTech Connect

    Liu, Z.H. Zhang, D.Q. Sing, S.L. Chua, C.K. Loh, L.E.

    2014-08-15

    Multi-material processing in selective laser melting using a novel approach, by the separation of two different materials within a single dispensing coating system was investigated. 316L stainless steel and UNS C18400 Cu alloy multi-material samples were produced using selective laser melting and their interfacial characteristics were analyzed using focused ion beam, scanning electron microscopy, energy dispersive spectroscopy and electron back scattered diffraction techniques. A substantial amount of Fe and Cu element diffusion was observed at the bond interface suggesting good metallurgical bonding. Quantitative evidence of good bonding at the interface was also obtained from the tensile tests where the fracture was initiated at the copper region. Nevertheless, the tensile strength of steel/Cu SLM parts was evaluated to be 310 ± 18 MPa and the variation in microhardness values was found to be gradual along the bonding interface from the steel region (256 ± 7 HV{sub 0.1}) to the copper region (72 ± 3 HV{sub 0.1}). - Highlights: • Multi-material processing was successfully implemented and demonstrated in SLM. • Bi-metallic laminates of steel/Cu were successfully produced with the SLM process. • A substantial amount of Fe and Cu diffusion was observed at the bond interface. • Good metallurgical bonding was obtained at the interface of the steel/Cu laminates. • Highly refined microstructure was obtained due to rapid solidification in SLM.

  8. Comparison between Palm Oil Derivative and Commercial Thermo-Plastic Binder System on the Properties of the Stainless Steel 316L Sintered Parts

    NASA Astrophysics Data System (ADS)

    Ibrahim, R.; Azmirruddin, M.; Wei, G. C.; Fong, L. K.; Abdullah, N. I.; Omar, K.; Muhamad, M.; Muhamad, S.

    2010-03-01

    Binder system is one of the most important criteria for the powder injection molding (PIM) process. Failure in the selection of the binder system will affect on the final properties of the sintered parts. The objectives of this studied is to develop a novel binder system based on the local natural resources and environmental friendly binder system from palm oil derivative which is easily available and cheap in our country of Malaysia. The novel binder that has been developed will be replaced the commercial thermo-plastic binder system or as an alternative binder system. The results show that the physical and mechanical properties of the final sintered parts fulfill the Metal Powder Industries Federation (MPIF) standard 35 for PIM parts. The biocompatibility test using cell osteosarcoma (MG63) and vero fibroblastic also shows that the cell was successfully growth on the sintered stainless steel 316L parts indicate that the novel binder was not toxic. Therefore, the novel binder system based on palm oil derivative that has been developed as a binder system fulfills the important criteria for the binder system in PIM process.

  9. Effect of Welding Current and Time on the Microstructure, Mechanical Characterizations, and Fracture Studies of Resistance Spot Welding Joints of AISI 316L Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Kianersi, Danial; Mostafaei, Amir; Mohammadi, Javad

    2014-09-01

    This article aims at investigating the effect of welding parameters, namely, welding current and welding time, on resistance spot welding (RSW) of the AISI 316L austenitic stainless steel sheets. The influence of welding current and welding time on the weld properties including the weld nugget diameter or fusion zone, tensile-shear load-bearing capacity of welded materials, failure modes, energy absorption, and microstructure of welded nuggets was precisely considered. Microstructural studies and mechanical properties showed that the region between interfacial to pullout mode transition and expulsion limit is defined as the optimum welding condition. Electron microscopic studies indicated different types of delta ferrite in welded nuggets including skeletal, acicular, and lathy delta ferrite morphologies as a result of nonequilibrium phases, which can be attributed to a fast cooling rate in the RSW process. These morphologies were explained based on Shaeffler, WRC-1992, and pseudo-binary phase diagrams. The optimum microstructure and mechanical properties were achieved with 8-kA welding current and 4-cycle welding time in which maximum tensile-shear load-bearing capacity or peak load of the welded materials was obtained at 8070 N, and the failure mode took place as button pullout with tearing from the base metal. Finally, fracture surface studies indicated that elongated dimples appeared on the surface as a result of ductile fracture in the sample welded in the optimum welding condition.

  10. In-situ measurements of the oxidation of AISI 316L(NG) and its constituents (Fe,Cr, Ni) in ultra-supercritical water

    SciTech Connect

    Betova, Iva; Bojinov, Martin; Kinnunen, Petri; Lehtovuori, Viivi; Peltonen, Seppo; Penttila, Sami; Saario, Timo

    2006-07-01

    Several new nuclear reactor designs utilizing supercritical water as coolant are currently being developed. In the European concept the design pressure is 25 MPa and reactor inlet/outlet temperatures 290 deg C/520 deg C. While benefits include better coolant thermal conductivity, increase in efficiency and simpler overall design, many material related questions need to be solved such as oxidation and radiation resistance with simultaneous need to maintain creep strength. This calls for the development of in-situ monitoring methods for the material/environment combination in question. In the present paper, in-situ electrical and electrochemical measurements during oxidation of AISI 316L(NG) and its pure metal constituents (Fe,Cr and Ni) in ultra-supercritical water (500-700 deg C, 30 MPa) have been reproducibly obtained. The oxidation kinetics was followed using the contact electric resistance (CER) and contact electric impedance (CEI) techniques. First attempts have been made to correlate properties of the resulting oxides with the corresponding weight gain data. In addition, impedance spectra of the Ni-Ni contact during oxidation have been reproducibly measured at 500 and 600 deg C. They could be quantitatively interpreted using general considerations of the corrosion process and the Mixed-Conduction Model for oxide films. Preliminary estimates of the diffusion coefficients of principal ionic and electronic current carriers have been obtained and their relevance with respect to available data on Ni oxidation is discussed. (authors)

  11. The electroplated Pd-Co alloy film on 316 L stainless steel and the corrosion resistance in boiling acetic acid and formic acid mixture with stirring

    NASA Astrophysics Data System (ADS)

    Li, Sirui; Zuo, Yu; Tang, Yuming; Zhao, Xuhui

    2014-12-01

    Pd-Co alloy films were deposited on 316 L stainless steel by electroplating. Scanning electronic microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, weight loss test and polarization test were used to determine the properties of the Pd-Co alloy films. The Pd-Co films show fine grain size, low porosity and obviously high micro-hardness. The Co content in the film can be controlled in a large range from 21.9 at.% to 57.42 at.%. Pd is rich on the Pd-Co film surface, which is benefit to increase the corrosion resistance. In boiling 90% acetic acid plus 10% formic acid mixture with 0.005 M Br- under stirring, the Pd-Co plated stainless steel samples exhibit evidently better corrosion resistance in contrast to Pd plated samples. The good corrosion resistance of the Pd-Co alloy film is explained by the better compactness, the lower porosity, and the obviously higher micro-hardness of the alloy films, which increases the resistance to erosion and retards the development of micro-pores in the film.

  12. Influences of deposition strategies and oblique angle on properties of AISI316L stainless steel oblique thin-walled part by direct laser fabrication

    NASA Astrophysics Data System (ADS)

    Wang, Xinlin; Deng, Dewei; Qi, Meng; Zhang, Hongchao

    2016-06-01

    Direct laser fabrication (DLF) developed from laser cladding and rapid prototyping technique has been widely used to fabricate thin-walled parts exhibiting more functions without expending weight and size. Oblique thin-walled parts accompanied with inhomogeneous mechanical properties are common in application. In the present study, a series of AISI316L stainless steel oblique thin-walled parts are successfully produced by DLF, in addition, deposition strategies, microstructure, and mechanical property of the oblique thin-walled parts are investigated. The results show that parallel deposition way is more valuable to fabricate oblique thin-walled part than oblique deposition way, because of the more remarkable properties. The hardness of high side initially increases until the distance to the substrate reaches about 25 mm, and then decreases with the increase of the deposition height. Oblique angle has a positive effect on the tensile property but a negative effect on microstructure, hardness and elongation due to the more tempering time. The maximum average ultimate tensile strength (UTS) and elongation are presented 744.3 MPa and 13.5% when the angle between tensile loading direction and horizontal direction is 45° and 90°, respectively.

  13. Cosintering of Powder Injection Molding Parts Made from Ultrafine WC-Co and 316L Stainless Steel Powders for Fabrication of Novel Composite Structures

    NASA Astrophysics Data System (ADS)

    Simchi, A.; Petzoldt, F.

    2010-01-01

    Sintering response and phase formation during sintering of WC-Co/316L stainless steel composites produced by assembling of powder injection molding (PIM) parts were studied. It is shown that during cosintering a significant mismatch strain (>4 pct) is developed in the temperature range of 1080 °C to 1350 °C. This mismatch strain induces biaxial stresses at the interface, leading to interface delamination. Experimental results revealed that sintering at a heating rate of 20 K/min could be used to decrease the mismatch strain to <2 pct. Meanwhile, WC is decomposed at the contact area and the diffusion of C and Co into the iron lattice results in the formation of a liquid and MC and M6C carbides at 1220 °C. Spreading of the liquid accelerates the reaction, affecting the dimensional stability of the PIM parts. To prevent the reaction, surface oxidation of the cemented carbide followed by hydrogen reduction during sintering was examined. Although the amount of mismatch strain increased, formation of a metallic interface consisting of a W-Co alloy (45 to 50 at. pct Co) and a Co-rich iron alloy (18 at. pct Co) prevented the decomposition of WC and melt formation. It is also shown that the deposition of a thin Ni layer after thermal debinding decreases the mismatch stresses through melt formation, although interlayer diffusion causes pore-band formation close to the steel part.

  14. The effect of synthetic scrubber solution chemistry on the corrosion behavior of type 316L stainless steel and Titanium Grade 2

    SciTech Connect

    Koch, G.H.; Beavers, J.A.; Whitman, L.

    1983-01-01

    A laboratory study was performed to investigate the effects of major solution variables of synthetic scrubber environments on the corrosion behavior of Type 316L Stainless Steel and Titanium Grade 2. The synthetic solution was calcium-based and contained magnesium, sodium, sulfate, chloride and fluoride. In solution preparation, it was found that the amount of sulfuric acid needed to achieve pH 1 was dependent on the chloride concentration. However, when the pH was adjusted to 1 prior to adding halides, the pH was found to decrease with increasing chloride concentration, whereas an increase in pH with increasing chloride concentration was observed when the initial pH was 4. When the pH was held constant, the corrosion rates of both the stainless steel and titanium decreased considerably with increasing chloride concentration above 30,000 ppm chloride. However, when the acid concentration was held constant, the corrosion rates of both alloys increased with increasing chloride concentration. Finally, corrosion rates decreased dramatically with increasing pH. An explanation of these observations is presented in terms of common ion effects and hydrogen ion activity.

  15. Measurement methods for surface oxides on SUS 316L in simulated light water reactor coolant environments using synchrotron XRD and XRF

    NASA Astrophysics Data System (ADS)

    Watanabe, Masashi; Yonezawa, Toshio; Shobu, Takahisa; Shoji, Tetsuo

    2013-03-01

    Synchrotron X-ray diffraction (XRD) and X-ray fluorescent (XRF) measurement techniques have been used for non-destructive characterization of surface oxide films on Type 316L austenitic stainless steels that were exposed to simulated primary water environments of pressurized water reactors (PWR) and boiling water reactors (BWR). The layer structures of the surface spinel oxides were revealed ex situ after oxidation by measurements made as a function of depth. The layer structure of spinel oxides formed in simulated PWR primary water should normally be different from that formed in simulated BWR water. After oxidation in the simulated BWR environment, the spinel oxide was observed to contain NiFe2O4 at shallow depths, and FeCr2O4 and Fe3O4 at deeper depths. By contrast, after oxidation in the simulated PWR primary water environment, a Fe3O4 type spinel was observed near the surface and FeCr2O4 type spinel near the interface with the metal substrate. Furthermore, by in situ measurements during oxidation in the simulated BWR environment, it was also demonstrated that the ratio between spinel and hematite Fe2O3 can be changed depending on the water condition such as BWR normal water chemistry or BWR hydrogen water chemistry.

  16. Spectroscopic and microscopic investigation of the corrosion of 316/316L stainless steel by lead-bismuth eutectic (LBE) at elevated temperatures: importance of surface preparation

    NASA Astrophysics Data System (ADS)

    Johnson, Allen L.; Parsons, Denise; Manzerova, Julia; Perry, Dale L.; Koury, Dan; Hosterman, Brian; Farley, John W.

    2004-07-01

    The corrosion of steel by lead-bismuth eutectic (LBE) is an important issue in proposed nuclear transmutation schemes. Russian scientists at the IPPE exposed steel samples to oxygen-controlled LBE at temperatures up to 823 K and exposure times up to 3000 h. We have characterized these post-exposure steel samples and unexposed controls, using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). Previous researchers have investigated the corrosion by LBE of steel of varying composition. In the present work, we compared two samples having the same composition (standard nuclear grade 316/316L) but different surface preparation: a cold-rolled sample was compared with an annealed sample. The cold-rolled sample had an order of magnitude less corrosion (i.e., both lower oxidation and less weight change) than the annealed sample. Sputter depth profiling of the exposed annealed sample and cold-rolled sample showed a marked difference in oxide layer composition between the annealed and cold-rolled samples. The annealed sample showed a complex oxide structure (iron oxide over chromium/iron oxide mixtures) of tens of microns thickness, while the cold-rolled sample was covered with a rather simple, primarily chromium oxide layer of ˜1 μm thickness.

  17. Influence of LBE long term exposure and simultaneous fast neutron irradiation on the mechanical properties of T91 and 316L

    NASA Astrophysics Data System (ADS)

    Stergar, E.; Eremin, S. G.; Gavrilov, S.; Lambrecht, M.; Makarov, O.; Iakovlev, V.

    2016-05-01

    The LEXUR-II-LBE irradiation campaign was conducted from 2011 to 2012 and was aimed to investigate the combined influence of irradiation and LBE environment. In this irradiation campaign tensile test samples, pressurized tubes and corrosion samples were irradiated in LBE filled capsules. To separate the effect of exposure to LBE and neutron irradiation a parallel furnace experiment where the samples were exposed to LBE at the irradiation temperature for the corresponding time was conducted. Here we report results of the first extracted capsule which was irradiated about 6 months and dismantled after a cooling phase to decrease activity. The results of SSRT tests for irradiated T91 show that the exposure to LBE at 350 °C for a long time leads to the appearance of liquid metal embrittlement without any pre-treatment which is usually necessary to promote LME. Irradiation increases the effect of LME on the ductility of T91. In contrast to the findings for T91 the gained results also show that tensile tests on irradiated austenitic stainless steel 316L show no influence of LBE environment on the tensile properties.

  18. Effect of ferrite transformation on the tensile and stress corrosion properties of type 316 L stainless steel weld metal thermally aged at 873 K

    NASA Astrophysics Data System (ADS)

    Shaikh, H.; Khatak, H. S.; Seshadri, S. K.; Gnanamoorthy, J. B.; Rodriguez, P.

    1995-07-01

    This article deals with the effect of the microstructural changes, due to transformation of delta ferrite, on the associated variations that take place in the tensile and stress corrosion properties of type 316 L stainless steel weld deposits when subjected to postweld heat treatment at 873 K for prolonged periods (up to 2000 hours). On aging for short durations (up to 20 hours), carbide/ carbonitride was the dominant transformation product, whereas sigma phase was dominant at longer aging times. The changes in the tensile and stress corrosion behavior of the aged weld metal have been attributed to the two competitive processes of matrix softening and hardening. Yield strength (YS) was found to depend predominantly on matrix softening only, while sig-nificant changes in the ultimate tensile strength (UTS) and the work-hardening exponent, n, occurred due to matrix hardening. Ductility and stress corrosion properties were considerably affected by both factors. Fractographic observations on the weld metal tested for stress-corrosion cracking (SCC) indicated a combination of transgranular cracking of the austenite and interface cracking.

  19. Coating process and early stage adhesion evaluation of poly(2-hydroxy-ethyl-methacrylate) hydrogel coating of 316L steel surface for stent applications.

    PubMed

    Indolfi, Laura; Causa, Filippo; Netti, Paolo Antonio

    2009-07-01

    In this study, a spray-coating method has been set up with the aim to control the coating of poly(2-hydroxy-ethyl-methacrylate) (pHEMA), an hydrophilic polymeric hydrogel, onto the complex surface of a 316L steel stent for percutaneous coronary intervention (PCI). By varying process parameters, tuneable thicknesses, from 5 to 20 microm, have been obtained with uniform and homogeneous surface without crack or bridges. Surface characteristics of pHEMA coating onto metal surface have been investigated through FTIR-ATR, contact angle measurement, SEM, EDS and AFM. Moreover, results from Single-Lap-Joint and Pull-Off adhesion tests as well as calorimetric analysis of glass transition temperature suggested that pHEMA deposition is firmly adhered on metallic surface. The pHEMA coating evaluation of roughness, wettability together with its morphological and chemical stability after three cycles of expansion-crimping along with preliminary results after 6 months demonstrates the suitability of the coating for surgical implantation of stent. PMID:19267260

  20. Understanding the corrosion behavior of chromia-forming 316L stainless steel in dual oxidizing-reducing environment representative of SOFC interconnect

    SciTech Connect

    Ziomek-Moroz, Margaret; Cramer, Stephen D.; Holcomb, Gordon R.; Covino, Bernard S., Jr.; Matthes, Steven A.; Bullard, Sophie J.; Dunning, John S.; Alman, David E.; Singh, P.

    2003-11-01

    A and B site doped LaCrO3-based electronically conducting Perovskite ceramic materials have been extensively used as interconnects in solid oxide fule cells (SOFC) operating at 800° to 1000°C as the Perovskites offer good electrical conductivity, chemical compatibility with the adjacent components of the fuel cell, chemical stability in reducing and oxidizing atmospheres, and thermal expansion coefficients that match other cell components. However, requirements for good mechanical properties, electrical and thermal conductivities, and low cost make metallic interconnects more promising. Significant progress in reducing the operating temperature of SOFC from ~1000°C to ~750°C is expected to permit the use of metallic materials with substantial cost reduction. Among the commercially available metallic materials, Cr2O3 (chromia) scale-forming iron base alloys appear to be the most promising candidates since they can fulfill the technical and economical requirements. These alloys, however, remain prone to reactions with oxygen and water vapor at fuel cell operating conditions and formation of gaseous chromium oxides and oxyhydroxides. To study the degradation processes and corrosion mechanisms of commercial chromia scale-forming alloys under SOFC interconnect exposure conditions, 316L was selected for this research because of the availability of the materials. The dual environment to which the interconnect material was exposed consisted of dry air (simulates the cathode side environment) and a mixture of H2 and 3% H2O (simulates the anode side environment). Post-corrosion surface evaluation involved the use of optical and scanning electron microscopy, as well as energy dispersive X-ray analyses.

  1. Effect of Specimen Diameter on Tensile Properties of Austenitic Stainless Steels in Liquid Hydrogen and Gaseous Helium at 20K

    NASA Astrophysics Data System (ADS)

    Fujii, H.; Ohmiya, S.; Shibata, K.; Ogata, T.

    2006-03-01

    Tensile tests using round bar type specimens of 3, 5 and 7 mm in diameter were conducted at 20K in liquid hydrogen and also in gaseous helium at the same temperature for three major austenitic stainless steels, JIS SUS304L, 316L and 316LN, extensively used for cryogenic applications including liquid hydrogen transportation and storage vessels. Stress-strain curves were considerably different between circumstances and also specimen diameter, resulting in differences of strength and ductility. In liquid hydrogen, serrated deformation appeared after considerable work hardening and more active in specimens with larger diameter. Meanwhile serrated deformation was observed from the early stage of plastic deformation in gaseous helium at 20 K and serration was more frequent in specimens with smaller diameter. The serrated deformation behaviors were numerically simulated for 304L steel with taking thermal properties such as thermal conductivity, specific heat, heat transfer from specimens to cryogenic media into account, and some agreement with the experiments was obtained.

  2. Effect of Specimen Diameter on Tensile Properties of Austenitic Stainless Steels in Liquid Hydrogen and Gaseous Helium at 20K

    SciTech Connect

    Fujii, H.; Ohmiya, S.; Shibata, K.; Ogata, T.

    2006-03-31

    Tensile tests using round bar type specimens of 3, 5 and 7 mm in diameter were conducted at 20K in liquid hydrogen and also in gaseous helium at the same temperature for three major austenitic stainless steels, JIS SUS304L, 316L and 316LN, extensively used for cryogenic applications including liquid hydrogen transportation and storage vessels. Stress-strain curves were considerably different between circumstances and also specimen diameter, resulting in differences of strength and ductility. In liquid hydrogen, serrated deformation appeared after considerable work hardening and more active in specimens with larger diameter. Meanwhile serrated deformation was observed from the early stage of plastic deformation in gaseous helium at 20 K and serration was more frequent in specimens with smaller diameter. The serrated deformation behaviors were numerically simulated for 304L steel with taking thermal properties such as thermal conductivity, specific heat, heat transfer from specimens to cryogenic media into account, and some agreement with the experiments was obtained.

  3. Free Radical Production in Immune Cell Systems Induced by Ti, Ti6Al4V and SS Assessed by Chemiluminescence Probe Pholasin Assay

    PubMed Central

    P. Cachinho, Sandra C.; Pu, Fanrong

    2012-01-01

    The oxidative burst of human blood cells in the presence of different metal materials was investigated using chemiluminescence assay. Commercial pure titanium (Ti), titanium alloy (Ti6Al4V), and stainless steel 316L (SS) in particulate form with <20 μm in size were used. The effect of particulate materials opsonisation on the upregulation of the respiratory burst production by blood cells was also assessed. The largest chemiluminescence response was achieved after simultaneous injection of the stimulants fMLP+PMA. Moreover, Ti and SS induced a greater inflammatory reaction compared to Ti6Al4V, since the respiratory burst mounted was higher for both materials after opsonisation treatment. These results suggest that in vitro chemiluminescence response and respiratory burst measurements proved to be composition and treatment dependent. PMID:22778739

  4. Corrosion behavior of austenitic steels 1.4970, 316L and 1.4571 in flowing LBE at 450 and 550 °C with 10-7 mass% dissolved oxygen

    NASA Astrophysics Data System (ADS)

    Tsisar, Valentyn; Schroer, Carsten; Wedemeyer, Olaf; Skrypnik, Aleksandr; Konys, Jürgen

    2014-11-01

    Corrosion behavior of austenitic steels 1.4571, 1.4970 and 316L was investigated in flowing oxygen-controlled LBE (2 m/s, 10-7 mass% O) at 450 and 550 °C for up to 8766 and 2011 h, respectively. The corrosion modes and material loss were analyzed qualitatively and quantitatively. Steels underwent both oxidation accompanied by formation of a thin (⩽0.5 μm) Cr-based oxide film and selective leaching of Ni and Cr that resulted in formation of a layer-type ferrite zone and deeper local damages with pit-type appearance both penetrated by Bi and Pb. The corrosion loss increases with time and temperature providing that the oxygen content is constant (10-7 mass%). Detailed quantitative analyses of corrosion loss showed that at 450 °C metal recession of steels ranged from 4 to 27 μm after 8766 h. Maximum depth of local attack reached 114, 183 and 210 μm for 1.4571, 1.4970 and 316L steels, respectively. At 550 °C metal recession ranged from 23 to 60 μm after 2011 h that correlates well with thickness of ferrite layer formed. The maximum depth of local attack reached 587, 207 and 158 μm for 1.4571, 1.4970 and 316L steels, respectively. The effect of composition, surface state and bulk micro-structure on the corrosion response of steels is discussed. The results are compared with those obtained in LBE with higher oxygen concentration, i.e., 10-6 mass% O.

  5. Distribution of soluble and precipitated iron and chromium products generated by anodic dissolution of 316L stainless steel and alloy C-22: final report

    SciTech Connect

    Estill, J; Farmer, J; Gordon, S; King, K; Logotetta, L; Silberman, D

    1999-08-11

    At near neutral pH and at applied potentials above the threshold potential for localized breakdown of the passive film, virtually all of the dissolved chromium appeared to be in the hexavalent oxidation state (Cr(VI)). In acidic environments, such as crevice solutions formed during the crevice corrosion of 316L and C-22 samples in 4 M NaCl, virtually all of the dissolved chromium appeared to be in the trivalent oxidation state (Cr(III)). These general observations appear to be consistent with the Pourbaix diagram for chromium (Pourbaix 1974), pp. 307-321. At high pH and high anodic polarization (pH {approximately} 8 and 800 mV vs. SHE), the predominate species is believed to be the soluble chromate anion (CrO{sub 4}{sup 2{minus}}). At the same pH, but lower polarization (pH {approximately} 8 and 0 mV vs. SHE), the predominate species are believed to be precipitates such as trivalent Cr(OH){sub 3} {center_dot} n(H{sub 2}O) and hexavalent Cr{sub 2}O{sub 3}. In acidified environments such as those found in crevices (pH < 3), soluble Cr{sup 3+} is expected to form over a wide range of potential extending from 400 mV vs. SHE to approximately 1200 mV vs. SHE. Again, this is consistent with the observations from the creviced samples. In earlier studies by the principal investigator, it has been found that low-level chromium contamination in ground water is usually in the hexavalent oxidation state (Farmer et al. 1996). In general, dissolved iron measured during the crevice experiments appears to be Fe(II) in acidic media and Fe(III) in near-neutral and alkaline solutions (table 3). In the case of cyclic polarization measurements, the dissolved iron measured at the end of some cyclic polarization measurements with C-22 appeared to be in the Fe(III) state. This is probably due to the high electrochemical potential at which these species were generated during the potential scan. Note that the reversal potential was approximately 1200 mV vs. Ag/AgCl during these scans. These

  6. Tritium uptake by SS316 and its decontamination

    NASA Astrophysics Data System (ADS)

    Torikai, Y.; Penzhorn, R.-D.; Matsuyama, M.; Watanabe, K.

    2004-08-01

    As-received and highly polished SS316 specimens were loaded with HT at 473-573 K. The uptake by polished samples was found to be up to five times that of as-received ones, when loading was performed immediately after polishing. This disparity vanished when polished specimens were subjected to a prolonged exposure to air prior to loading. The tritium loss from tritium-loaded SS316 specimens was examined by chemical etching and by thermal release in a flow system using various carrier gases at several temperatures. While at moderate temperatures the type of carrier has an impact on the tritium release rate, at higher ones this effect disappears. Moisture in the carrier gas has little influence on the loss rate of bulk tritium. Etching depth profiles of specimens previously heat-treated in the presence of air or Ar + H 2 and of untreated specimens are given. Evidence for chronic tritium liberation from SS316 at 298 K is provided.

  7. Improved corrosion resistance and interfacial contact resistance of 316L stainless-steel for proton exchange membrane fuel cell bipolar plates by chromizing surface treatment

    NASA Astrophysics Data System (ADS)

    Lee, S. B.; Cho, K. H.; Lee, W. G.; Jang, H.

    The electrochemical performance and electrical contact resistance of chromized 316 stainless-steel (SS) are investigated under simulated operating condition in a proton-exchange membrane fuel cell (PEMFC). The corrosion resistance of the chromized stainless steel is assessed by potentiodynamic and potentiostatic tests and the interfacial contact resistance (ICR) is examined by measuring the electrical contact resistance as a function of the compaction force. The results show that the chromizing surface treatment improves the corrosion resistance of the stainless steel due to the high-chromium concentration in the diffuse coating layer. On the other hand, the excess Chromium content on the surface increases the contact resistance of the steel plate to a level that is excessively high for commercial applications. This study examines the root cause of the high-contact resistance after chromizing and reports the optimum process to improve the corrosion resistance without sacrificing the ICR by obtaining a chrome carbide on the outer layer.

  8. Orientation of histopathology specimens.

    PubMed

    Burns, A; Adams, J; Endersby, S

    2004-02-01

    We present a simple way of orientating large specimens being sent to the laboratory for histopathological examination by supplementing the pinning of the specimen on a cork board with Polaroid photographs of the specimen and numbered tags. PMID:14706306

  9. Cinemicrographic specimen housing

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.

    1979-01-01

    Housing used to observe gravitation effects on specimens embedded in support media, such as agar, supports microbial specimens vertically for time-lapsed cinemicrographic studies. Procedure cannot be performed with conventional microscopes which see specimens in horizontal plane only.

  10. A Study on the Laser Spatter and the Oxidation Reactions During Selective Laser Melting of 316L Stainless Steel, Al-Si10-Mg, and Ti-6Al-4V

    NASA Astrophysics Data System (ADS)

    Simonelli, Marco; Tuck, Chris; Aboulkhair, Nesma T.; Maskery, Ian; Ashcroft, Ian; Wildman, Ricky D.; Hague, Richard

    2015-09-01

    The creation of an object by selective laser melting (SLM) occurs by melting contiguous areas of a powder bed according to a corresponding digital model. It is therefore clear that the success of this metal Additive Manufacturing (AM) technology relies on the comprehension of the events that take place during the melting and solidification of the powder bed. This study was designed to understand the generation of the laser spatter that is commonly observed during SLM and the potential effects that the spatter has on the processing of 316L stainless steel, Al-Si10-Mg, and Ti-6Al-4V. With the exception of Ti-6Al-4V, the characterization of the laser spatter revealed the presence of surface oxides enriched in the most volatile alloying elements of the materials. The study will discuss the implication of this finding on the material quality of the built parts.

  11. Measurement of hydrogen permeation through SUS 316L for pressures from 0.8 to 2.0 bar and thicknesses from 1 to 3 mm at 800°C

    NASA Astrophysics Data System (ADS)

    Lee, S. K.; Noh, S. J.; In, S. R.

    2012-07-01

    A detailed understanding of the permeation of hydrogen isotopes through structural materials is an important issue concerning the reliability, safety, fuelling and environmental impact of fusion power reactors. The permeation of hydrogen through SUS 316L stainless steel, which will be used in various parts of fusion power reactors, was investigated at an elevated temperature of 800 °C. From experiments at different hydrogen feed pressures of 0.8, 1.0, 1.5, and 2.0 bar with a 3-mm-thick membrane coupon, the hydrogen pressure exponent was determined, and the rate-limiting step for the permeation was determined to be bulk diffusion. From experiments using membranes of various thicknesses of 1, 2, and 3 mm at 1 bar, the effect of the membrane thickness on the hydrogen permeation was studied and discussed in relation to the bulk diffusion process. The results and the discussions for the hydrogen permeation experiments are presented here.

  12. Urine culture - catheterized specimen

    MedlinePlus

    Culture - urine - catheterized specimen; Urine culture - catheterization; Catheterized urine specimen culture ... urinary tract infections may be found in the culture. This is called a contaminant. You may not ...

  13. ROLE OF SCALE FACTOR DURING TENSILE TESTING OF SMALL SPECIMENS

    SciTech Connect

    Gussev, Maxim N; Busby, Jeremy T; Field, Kevin G; Sokolov, Mikhail A; Gray, Mr. Sean

    2014-01-01

    The influence of scale factor (tensile specimen geometry and dimensions) on mechanical test results was investigated for different widely used types of small specimens (SS-1, SS-2, SS-3, and SS-J3) and a set of materials. It was found that the effect of scale factor on the accurate determination of yield stress, ultimate tensile stress, and uniform elongation values was weak; however, clear systematic differences were observed and should be accounted for during interpretation of results. In contrast, total elongation values were strongly sensitive to variations in specimen geometry. Modern experimental methods like digital image correlation allow the impact of scale factor to be reduced. Using these techniques, it was shown that true stress true strain curves describing strain-hardening behavior were very close for different specimen types. The limits of miniaturization are discussed, and an ultra-miniature specimen concept was suggested and evaluated. This type of specimen, as expected, may be suitable for SEM and TEM in situ testing.

  14. Upgraded Neutron Dosimetry Procedure for VVER-440 Surveilance Specimens

    NASA Astrophysics Data System (ADS)

    Kochkin, V.; Erak, D.; Zaritsky, S.; Egorov, A.; Makhotin, D.

    2009-08-01

    The control of Reactor Pressure Vessel (RPV) metal during lifetime is one of the basic conditions of the reliable and safe operation of a reactor and NPP as a whole. The substantiation of safe RPV operation is based on Surveillance Specimens (SS) testing results and their transfer to the RPV. Since the reliability of the SS program directly depends on the dosimetry accuracy, one of the most important tasks in the investigation of SS is precision estimation of fast neutron fluence (E > 0.5MeV) for each specimen. The upgraded procedure of neutron fluence evaluation for surveillance specimens of VVER-440/213 reactor has been developed and is presented in this paper. This procedure based on measurements of the 54Mn activity of each of the surveillance specimens and neutron field computations. In contrast to the earlier procedures the new one takes into account correctly all pressure vessel internals, influence of core pattern on the neutron field in SS channel, and dependence of spectral index SI0.5/3.0 on the axial coordinate of surveillance specimens. The upgraded procedure is used for neutron fluence evaluation of VVER-440 surveillance and research programs in RRC "Kurchatov institute".

  15. Specimen collection and preservation

    USGS Publications Warehouse

    Franson, J. Christian

    1987-01-01

    Specimens, as discussed in this handbook, have but a single purpose--to provide information leading to the diagnosis of a cause of disease or death. A specimen may be an intact carcass, various tissues removed from carcasses, or parasites. In any event, the specimen should be as fresh and undamaged as possible.

  16. OR Specimen Labeling.

    PubMed

    Zervakis Brent, Mary Ann

    2016-02-01

    Mislabeled surgical specimens jeopardize patient safety and quality care. The purpose of this project was to determine whether labeling surgical specimens with two patient identifiers would result in an 80% reduction in specimen labeling errors within six months and a 100% reduction in errors within 12 months. Our failure mode effects analysis found that the lack of two patient identifiers per label was the most unsafe step in our specimen handling process. We piloted and implemented a new process in the OR using the Plan-Do-Check-Act conceptual framework. The audit process included collecting data and making direct observations to determine the sustainability of the process change; however, the leadership team halted the direct observation audit after four months. The total number of surgical specimen labeling errors was reduced by only 60% within six months and 62% within 12 months; therefore, the goal of the project was not met. However, OR specimen labeling errors were reduced. PMID:26849982

  17. A subsized fatigue specimen

    NASA Technical Reports Server (NTRS)

    Jeelani, S.; Natarajan, R.; Reddy, G. R.

    1986-01-01

    A subsized fatigue specimen has been designed to overcome the difficulty of machining a full-sized specimen from cast superalloy components. A finite element analysis confirmed that the stress was maximum at the gauge section for any given set of clamping and tensile loads, and that the stresses developed due to clamping forces were negligible compared with those due to tensile or compressive loads. Fatigue data generated using subsized specimens of AISI 4130 steel, 2024-T4 aluminum alloy and 6Al-4V titanium alloy compared well with those available in the literature for full-sized specimens.

  18. Infrared variability of SS 433

    NASA Technical Reports Server (NTRS)

    Kodaira, K.; Nakada, Y.; Backman, D. E.

    1985-01-01

    New JHKLM photometry of SS 433 showing short time scale variabilities is reported for the period of 1983 July 16-22 UT. The entire body of infrared data included in this paper, Giles et al. (1980), and Catchpole et al. (1981), is examined with reference to periods of 164 days and 13.08 days. Comparison of the infrared light curves with the optical light curves of Leibowitz et al. (1984) makes it possible to conclude, within the context of an accretion disk model, that the majority of the infrared flux in the SS 433 system comes from the disk, and that the hot spot responsible for the 'hump' in the visual and infrared light curves has a color similar to the average of the disk. A two-dimensional Fourier analysis of the infrared data suggests that the brightness maximum occurs when, seen from the compact star, the noncompact companion passes through a fixed elongation relative to the disk line of nodes with the orbital plane, if the precession is prograde.

  19. Corrosion erosion test of SS316 in flowing Pb Bi

    NASA Astrophysics Data System (ADS)

    Kikuchi, K.; Kurata, Y.; Saito, S.; Futakawa, M.; Sasa, T.; Oigawa, H.; Wakai, E.; Miura, K.

    2003-05-01

    Corrosion tests of austenitic stainless tube were done under flowing Pb-Bi conditions for 3000 h at 450 °C. Specimens were 316SS produced as a tubing form with 13.8 mm outer diameter, 2 mm thickness and 40 cm length. During operation, maximum temperature, temperature difference and flow velocity of Pb-Bi at the specimen were kept at 450, 50 °C, and 1 m/s, respectively. After the test, specimen and components of the loop were cut and examined by optical microscope, SEM, EDX, WDX and X-ray diffraction. Pb-Bi adhered on the surface of the specimen even after Pb-Bi was drained out to the storage tank from the circulating loop. Results differed from a stagnant corrosion test in that the specimen surface became rough and the corrosion rate was maximally 0.1 mm/3000 h. Mass transfer from the high temperature to the lower temperature area was observed: crystals of Fe-Cr were found on the tube surface in the low-temperature region. The sizes of crystals varied from 0.1 to 0.2 mm. The depositing crystals were ferrite grains and the chemical composition ratio (mass%) of Fe to Cr was 9:1.

  20. 37 CFR 2.59 - Filing substitute specimen(s).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Filing substitute specimen(s..., DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.59 Filing substitute specimen(s). (a... specimen(s), the applicant must: (1) For an amendment to allege use under § 2.76, verify by affidavit...

  1. Controlled environment specimen transfer.

    PubMed

    Damsgaard, Christian D; Zandbergen, Henny; W Hansen, Thomas; Chorkendorff, Ib; B Wagner, Jakob

    2014-08-01

    Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3 catalyst for methanol synthesis and a Co/Al2O3 catalyst for Fischer-Tropsch synthesis. Both systems are sensitive to ambient atmosphere as they will oxidize after relatively short air exposure. The Cu/ZnO/Al2O3 catalyst, was reduced in the in situ X-ray diffractometer set-up, and subsequently, successfully transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ transfer holder facilitates complimentary in situ experiments of the same specimen without changing the specimen state during transfer. PMID:24824787

  2. Transport of viral specimens.

    PubMed Central

    Johnson, F B

    1990-01-01

    The diagnosis of viral infections by culture relies on the collection of proper specimens, proper care to protect the virus in the specimens from environmental damage, and use of an adequate transport system to maintain virus activity. Collection of specimens with swabs that are toxic to either virus or cell culture should be avoided. A variety of transport media have been formulated, beginning with early bacteriological transport media. Certain swab-tube combinations have proven to be both effective and convenient. Of the liquid transport media, sucrose-based and broth-based media appear to be the most widely accepted and used. Studies on virus stability show that most viruses tested are sufficiently stable in transport media to withstand a transport time of 1 to 3 days. Some viruses may withstand longer transport times. In many cases, it is not necessary to store virus specimens in a refrigerator or send them to the laboratory on wet ice or frozen on dry ice. However, the specimen should not be exposed to environmental extremes. Modern viral transport media allow for more effective use of viral culture and culture enhancement techniques for the diagnosis of human viral infections. PMID:2187591

  3. Conductive and corrosion behaviors of silver-doped carbon-coated stainless steel as PEMFC bipolar plates

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Xu, Hong-feng; Fu, Jie; Tian, Ying

    2016-07-01

    Ni-Cr enrichment on stainless steel SS316L resulting from chemical activation enabled the deposition of carbon by spraying a stable suspension of carbon nanoparticles; trace Ag was deposited in situ to prepare a thin continuous Ag-doped carbon film on a porous carbon-coated SS316L substrate. The corrosion resistance of this film in 0.5 mol·L-1 H2SO4 solution containing 5 ppm F- at 80°C was investigated using polarization tests. The results showed that the surface treatment of the SS316L strongly affected the adhesion of the carbon coating to the stainless steel. Compared to the bare SS316L, the Ag-doped carbon-coated SS316L bipolar plate was remarkably more stable in both the anode and cathode environments of proton exchange membrane fuel cell (PEMFC) and the interface contact resistance between the specimen and Toray 060 carbon paper was reduced from 333.0 mΩ·cm2 to 21.6 mΩ·cm2 at a compaction pressure of 1.2 MPa.

  4. Genomics and museum specimens.

    PubMed

    Nachman, Michael W

    2013-12-01

    Nearly 25 years ago, Allan Wilson and colleagues isolated DNA sequences from museum specimens of kangaroo rats (Dipodomys panamintinus) and compared these sequences with those from freshly collected animals (Thomas et al. 1990). The museum specimens had been collected up to 78 years earlier, so the two samples provided a direct temporal comparison of patterns of genetic variation. This was not the first time DNA sequences had been isolated from preserved material, but it was the first time it had been carried out with a population sample. Population geneticists often try to make inferences about the influence of historical processes such as selection, drift, mutation and migration on patterns of genetic variation in the present. The work of Wilson and colleagues was important in part because it suggested a way in which population geneticists could actually study genetic change in natural populations through time, much the same way that experimentalists can do with artificial populations in the laboratory. Indeed, the work of Thomas et al. (1990) spawned dozens of studies in which museum specimens were used to compare historical and present-day genetic diversity (reviewed in Wandeler et al. 2007). All of these studies, however, were limited by the same fundamental problem: old DNA is degraded into short fragments. As a consequence, these studies mostly involved PCR amplification of short templates, usually short stretches of mitochondrial DNA or microsatellites. In this issue, Bi et al. (2013) report a breakthrough that should open the door to studies of genomic variation in museum specimens. They used target enrichment (exon capture) and next-generation (Illumina) sequencing to compare patterns of genetic variation in historic and present-day population samples of alpine chipmunks (Tamias alpinus) (Fig. 1). The historic samples came from specimens collected in 1915, so the temporal span of this comparison is nearly 100 years. PMID:24138088

  5. 37 CFR 2.59 - Filing substitute specimen(s).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Filing substitute specimen(s). 2.59 Section 2.59 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.59 Filing substitute specimen(s)....

  6. 37 CFR 2.59 - Filing substitute specimen(s).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Filing substitute specimen(s). 2.59 Section 2.59 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.59 Filing substitute specimen(s)....

  7. 37 CFR 2.59 - Filing substitute specimen(s).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Filing substitute specimen(s). 2.59 Section 2.59 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.59 Filing substitute specimen(s)....

  8. Fracture strengths of HIPed DS-Cu/SS joints for ITER shielding blanket/first wall

    NASA Astrophysics Data System (ADS)

    Hatano, T.; Kanari, M.; Sato, S.; Gotoh, M.; Furuya, K.; Kuroda, T.; Saito, M.; Enoeda, M.; Takatsu, H.

    1998-10-01

    Fracture toughness and crack propagation tests were performed to investigate the effect of HIP temperature and fracture behavior of HIPed DS-Cu/SS joints. Test specimens of DS-Cu/SS HIPed joints were manufactured by bonding flat plates of DS-Cu and SS under HIP temperatures of 980°C, 1030°C and 1050°C. JQ of the joint at HIP temperature of 1050°C was larger than the other two joints. For the crack propagation test, two types of test specimens were prepared. One had a notch along the HIPed interface and the other in DS-Cu and normal to the interface. The crack in the former specimen propagated along the interface. On the other hand, the crack in the latter specimen propagated in the DS-Cu perpendicular to the loading direction, stopped at the interface, and then exfoliated along the HIPed interface. In the fracture tests, the crack was observed propagating in DS-Cu side at approximately 5-10 μm away from the interface.

  9. Anaerobic specimen transport device.

    PubMed Central

    Wilkins, T D; Jimenez-Ulate, F

    1975-01-01

    A device is described and evaluated for the anaerobic transport of clinical specimens. The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst. The viability on swabs of 12 species of anaerobes, four strains of facultative anaerobes and a strain of Pseudomonas aeruginosa, was maintained during the length of the tests (24 or 48 h). The results demonstrated that this device protected even the more oxygen-sensitive clinical anaerobes from death due to oxygen exposure. This device can be used for swabs as well as for anaerobic collection and liquid and solid specimens. Images PMID:1104656

  10. Biaxial Creep Specimen Fabrication

    SciTech Connect

    JL Bump; RF Luther

    2006-02-09

    This report documents the results of the weld development and abbreviated weld qualification efforts performed by Pacific Northwest National Laboratory (PNNL) for refractory metal and superalloy biaxial creep specimens. Biaxial creep specimens were to be assembled, electron beam welded, laser-seal welded, and pressurized at PNNL for both in-pile (JOYO reactor, O-arai, Japan) and out-of-pile creep testing. The objective of this test campaign was to evaluate the creep behavior of primary cladding and structural alloys under consideration for the Prometheus space reactor. PNNL successfully developed electron beam weld parameters for six of these materials prior to the termination of the Naval Reactors program effort to deliver a space reactor for Project Prometheus. These materials were FS-85, ASTAR-811C, T-111, Alloy 617, Haynes 230, and Nirnonic PE16. Early termination of the NR space program precluded the development of laser welding parameters for post-pressurization seal weldments.

  11. Multiaxial graphite test specimen

    SciTech Connect

    1988-09-01

    A multiaxial test program is to be conducted by Oak Ridge National Laboratory (ORNL) on the core component graphite. The objectives of the tests are to obtain failure data under uniaxial and biaxial states of stress in order to construct a failure surface in a two-dimensional stress space. These data will be used in verifying the accuracy of the maximum stress failure theory being proposed for use in designing the core graphite components. Tubular specimens are proposed to be used and are either loaded axially and/or subjected to internal pressure. This report includes a study on three specimen configurations. The conclusions of that study indicate that an elliptical transition geometry procedures the smallest discontinuity effects. Several loading combustions were studied using the elliptical transition specimen. The primary purpose is to establish the location of the highest stress state and its relation to the gage section for all of the loading conditions. The tension/internal pres sure loading condition (1:1) indicated that the high stress area is just outside the gage section but still should be acceptable. 5 refs., 18 figs.

  12. NASA Biological Specimen Repository

    NASA Technical Reports Server (NTRS)

    McMonigal, K. A.; Pietrzyk, R. A.; Sams, C. F.; Johnson, M. A.

    2010-01-01

    The NASA Biological Specimen Repository (NBSR) was established in 2006 to collect, process, preserve and distribute spaceflight-related biological specimens from long duration ISS astronauts. This repository provides unique opportunities to study longitudinal changes in human physiology spanning may missions. The NBSR collects blood and urine samples from all participating ISS crewmembers who have provided informed consent. These biological samples are collected once before flight, during flight scheduled on flight days 15, 30, 60, 120 and within 2 weeks of landing. Postflight sessions are conducted 3 and 30 days after landing. The number of in-flight sessions is dependent on the duration of the mission. Specimens are maintained under optimal storage conditions in a manner that will maximize their integrity and viability for future research The repository operates under the authority of the NASA/JSC Committee for the Protection of Human Subjects to support scientific discovery that contributes to our fundamental knowledge in the area of human physiological changes and adaptation to a microgravity environment. The NBSR will institute guidelines for the solicitation, review and sample distribution process through establishment of the NBSR Advisory Board. The Advisory Board will be composed of representatives of all participating space agencies to evaluate each request from investigators for use of the samples. This process will be consistent with ethical principles, protection of crewmember confidentiality, prevailing laws and regulations, intellectual property policies, and consent form language. Operations supporting the NBSR are scheduled to continue until the end of U.S. presence on the ISS. Sample distribution is proposed to begin with selections on investigations beginning in 2017. The availability of the NBSR will contribute to the body of knowledge about the diverse factors of spaceflight on human physiology.

  13. Method for thinning specimen

    DOEpatents

    Follstaedt, David M.; Moran, Michael P.

    2005-03-15

    A method for thinning (such as in grinding and polishing) a material surface using an instrument means for moving an article with a discontinuous surface with an abrasive material dispersed between the material surface and the discontinuous surface where the discontinuous surface of the moving article provides an efficient means for maintaining contact of the abrasive with the material surface. When used to dimple specimens for microscopy analysis, a wheel with a surface that has been modified to produce a uniform or random discontinuous surface significantly improves the speed of the dimpling process without loss of quality of finish.

  14. NASA Biological Specimen Repository

    NASA Technical Reports Server (NTRS)

    Pietrzyk, Robert; McMonigal, K. A.; Sams, C. F.; Johnson, M. A.

    2009-01-01

    The NASA Biological Specimen Repository (NBSR) has been established to collect, process, annotate, store, and distribute specimens under the authority of the NASA/JSC Committee for the Protection of Human Subjects. The International Space Station (ISS) provides a platform to investigate the effects of microgravity on human physiology prior to lunar and exploration class missions. The NBSR is a secure controlled storage facility that is used to maintain biological specimens over extended periods of time, under well-controlled conditions, for future use in approved human spaceflight-related research protocols. The repository supports the Human Research Program, which is charged with identifying and investigating physiological changes that occur during human spaceflight, and developing and implementing effective countermeasures when necessary. The storage of crewmember samples from many different ISS flights in a single repository will be a valuable resource with which researchers can validate clinical hypotheses, study space-flight related changes, and investigate physiological markers All samples collected require written informed consent from each long duration crewmember. The NBSR collects blood and urine samples from all participating long duration ISS crewmembers. These biological samples are collected pre-flight at approximately 45 days prior to launch, during flight on flight days 15, 30, 60 120 and within 2 weeks of landing. Postflight sessions are conducted 3 and 30 days following landing. The number of inflight sessions is dependent on the duration of the mission. Operations began in 2007 and as of October 2009, 23 USOS crewmembers have completed or agreed to participate in this project. As currently planned, these human biological samples will be collected from crewmembers covering multiple ISS missions until the end of U.S. presence on the ISS or 2017. The NBSR will establish guidelines for sample distribution that are consistent with ethical principles

  15. Middle Level SS&C Energy Series.

    ERIC Educational Resources Information Center

    Crow, Linda W.; Aldridge, Bill G.

    The project on Scope Sequence and Coordination of Secondary School Science (SS&C) was initiated by the National Science Teachers Association (NSTA) and recommends that all students study science every year and advocates carefully sequenced, well-coordinated instruction in biology, chemistry, earth/space science, and physics. This document…

  16. NARSTO EPA SS HOUSTON DMA DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON DMA DATA Project Title:  NARSTO ... Analyzer Optical Counter Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston DMA Guide Houston Project Plan  (PDF) Houston ...

  17. NARSTO EPA SS HOUSTON RAPID SPMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON RAPID SPMS DATA Project Title:  NARSTO ... Single-particle Mass Spectrometer Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston SPMS Guide Houston Project Plan  (PDF) Houston ...

  18. Effect of exposure time on corrosion resistance of prepassivated UNS S31603 SS in the Gulf of Mexico

    SciTech Connect

    Acuiia, N.; Herniindet-Duque, G.

    1998-12-31

    The effect of exposure time, in the Gulf of Mexico, on the UNS S3 1603 stainless steel (SS) pitting corrosion resistance (PCR), was studied for 30 days using both open circuit potential (OCP) and potentiodynamic polarization (PP) techniques. Biofilm formation and corrosion attack were subsequently observed using scanning electron microscope (SEM) and atomic force microscopy (AFM). It was found that microorganisms colonizing the steel specimen`s surface during the first three days of testing, modified the OCP towards electropositive values, increasing the risk of pitting corrosion. It was also observed, that the SS specimens were most sensitive to pitting corrosion within the first fifteen days of exposure in seawater, decreasing this sensitivity during the last week, probably due to a decay in the biological activity and better behavior of the passive film.

  19. An Ss Model with Adverse Selection.

    ERIC Educational Resources Information Center

    House, Christopher L.; Leahy, John V.

    2004-01-01

    We present a model of the market for a used durable in which agents face fixed costs of adjustment, the magnitude of which depends on the degree of adverse selection in the secondary market. We find that, unlike typical models, the sS bands in our model contract as the variance of the shock increases. We also analyze a dynamic version of the model…

  20. Migration and release behavior of tritium in SS316 at ambient temperature

    NASA Astrophysics Data System (ADS)

    Torikai, Y.; Murata, D.; Penzhorn, R.-D.; Akaishi, K.; Watanabe, K.; Matsuyama, M.

    2007-06-01

    BIXS measurements indicate that immersion into water or chemical etching of SS316 contaminated with tritium at moderate temperatures causes an immediate reduction of the outermost surface concentration of tritium. The fraction of surface tritium removed by water, i.e. 30-50%, is small in comparison to the total tritium present in the specimen. Allowing a specimen to age whose surface and subsurface had been removed by etching up to a depth where the concentration of tritium is mostly constant revealed that within a few months a re-growth of tritium up to a saturation value higher than half of that originally present on the specimen takes place. Concurrently, a small but steady liberation of tritium at rates increasing from 0.1 to 0.3 kBq/h was noticed.

  1. As-rigid-as-possible mosaicking and serial section registration of large ssTEM datasets

    PubMed Central

    Saalfeld, Stephan; Cardona, Albert; Hartenstein, Volker; Tomančák, Pavel

    2010-01-01

    Motivation: Tiled serial section Transmission Electron Microscopy (ssTEM) is increasingly used to describe high-resolution anatomy of large biological specimens. In particular in neurobiology, TEM is indispensable for analysis of synaptic connectivity in the brain. Registration of ssTEM image mosaics has to recover the 3D continuity and geometrical properties of the specimen in presence of various distortions that are applied to the tissue during sectioning, staining and imaging. These include staining artifacts, mechanical deformation, missing sections and the fact that structures may appear dissimilar in consecutive sections. Results: We developed a fully automatic, non-rigid but as-rigid-as-possible registration method for large tiled serial section microscopy stacks. We use the Scale Invariant Feature Transform (SIFT) to identify corresponding landmarks within and across sections and globally optimize the pose of all tiles in terms of least square displacement of these landmark correspondences. We evaluate the precision of the approach using an artificially generated dataset designed to mimic the properties of TEM data. We demonstrate the performance of our method by registering an ssTEM dataset of the first instar larval brain of Drosophila melanogaster consisting of 6885 images. Availability: This method is implemented as part of the open source software TrakEM2 (http://www.ini.uzh.ch/∼acardona/trakem2.html) and distributed through the Fiji project (http://pacific.mpi-cbg.de). Contact: tomancak@mpi-cbg.de PMID:20529937

  2. Screening and Identification of ssDNA Aptamer for Human GP73

    PubMed Central

    Du, Jingchun; Hong, Jianming; Xu, Chun; Cai, Yuanyuan; Xiang, Bo; Zhou, Chengbo; Xu, Xia

    2015-01-01

    As one tumor marker of HCC, Golgi Protein 73 (GP73) is given more promise in the early diagnosis of HCC, and aptamers have been developed to compete with antibodies as biorecognition probes in different detection system. In this study, we utilized GP73 to screen specific ssDNA aptamers by SELEX technique. First, GP73 proteins were expressed and purified by prokaryotic expression system and Nickle ion affinity chromatography, respectively. At the same time, the immunogenicity of purified GP73 was confirmed by Western blotting. The enriched ssDNA library with high binding capacity for GP73 was obtained after ten rounds of SELEX. Then, thirty ssDNA aptamers were sequenced, in which two ssDNA aptamers with identical DNA sequence were confirmed, based on the alignment results, and designated as A10-2. Furthermore, the specific antibody could block the binding of A10-2 to GP73, and the specific binding of A10-2 to GP73 was also supported by the observation that several tumor cell lines exhibited variable expression level of GP73. Significantly, the identified aptamer A10-2 could distinguish normal and cancerous liver tissues. So, our results indicate that the aptamer A10-2 might be developed into one molecular probe to detect HCC from normal liver specimens. PMID:26583119

  3. Fin Spine Bone Resorption in Atlantic Bluefin Tuna, Thunnus thynnus, and Comparison between Wild and Captive-Reared Specimens

    PubMed Central

    Santamaria, Nicoletta; Bello, Giambattista; Pousis, Chrysovalentinos; Vassallo-Agius, Robert; de la Gándara, Fernando; Corriero, Aldo

    2015-01-01

    Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorption was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions. PMID:25751271

  4. Pilot environmental specimen bank program

    SciTech Connect

    Wise, S.A.; Zeisler, R.

    1984-10-01

    The concept of an environmental specimen bank for archiving of biological and environmental samples for retrospective analysis has been recognized recently as an important component of systematic environmental monitoring. A pilot program was designed to evaluate the feasibility of a national program by providing actual working experience in all aspects of specimen banking, that is, in specimen collection, processing, storage, and analysis. Four types of environmental specimens, which represent environmental accumulators, were selected for inclusion in the National Bureau of Standards pilot program: human soft tissue (liver), a marine accumulator (marine mussels, Mytilus edulis), a food accumulator and the air pollutant accumulator have not been selected. Attention is focused on the experience gained in the pilot program with the human liver specimens. 32 references, 2 figures, 1 table.

  5. Status of ITER task T213 collaborative irradiation screening experiment on Cu/SS joints in the Russian Federation SM-2-reactor

    SciTech Connect

    Edwards, D.J.; Fabritsiev, S.A.; Pokrovsky, A.S.; Zinkle, S.J.

    1996-04-01

    Specimen fabrication is underway for an irradiation screening experiment planned to start in January 1996 in the SM-2 reactor in Dimitrovgrad, Russia. The purpose of the experiment is to evaluate the effects of neutron irradiation at ITER-relevant temperatures on the bond integrity performance of Cu/SS and Be/Cu joints, as well as to further investigate the base metal properties of irradiated copper alloys. Specimens from each of the four ITER parties (U.S., EU, japan, and RF) will be irradiated to a dose of {approx}0.2 dpa at two different temperatures, 150 and 300{degrees}C. The specimens will consist of Cu/SS and Be/Cu joints in several different geometries, as well as a large number of specimens from the base materials. Fracture toughness data on base metal and Cu/SS bonded specimens will be obtained from specimens supplied by the U.S. Due to lack of material, the Be/Cu specimens supplied by the U.S will only be irradiated as TEM disks.

  6. The Power of SS 433's Jets

    NASA Technical Reports Server (NTRS)

    Band, David F.

    1999-01-01

    We observed SS 433 for the third time with RXTE, this time simultaneously with a Nobeyama millimeter band monitoring campaign. These observations extended the RXTE coverage of SS 433's precession phases. and once again monitored the source during a binary eclipse. Our AO-2 campaign of a joint RXTE-VLBA-VLA-MERLIN observation was delayed to little more than a month before the AO-3 observations. We also had an AO-1 observation of SS 433. In each case we observed an eclipse of the compact ob'ect by the companion star, and had contemporaneous optical observations. We are analyzing all three sets of observations together. A publication is in preparation; Its completion will be supported by the remaining AO-2 funds. Here I will summarize the general results and point out the relevant features of the AO-3 observations. The spectrum is detected to approx. 50 keV, which is entirely within the PCA energy band. We find that the HEXTE data do not add significantly to the spectrum, and most of our fits are without HEXTE. We find that the continuum can be fit with a power law with an exponential cutoff; the photon index is usually approx. 1.4. A line at approx. 6.4 keV is definitely required, and the fits improve significant, if we add a second line, also with an energy in the iron K(alpha) complex, and an absorption edge. The edge usually has an energy of approx. 5.8 keV, which does not correspond to any known physical feature. and may be an instrumental artifact. This is under further investigation.

  7. Manufacturing of Plutonium Tensile Specimens

    SciTech Connect

    Knapp, Cameron M

    2012-08-01

    Details workflow conducted to manufacture high density alpha Plutonium tensile specimens to support Los Alamos National Laboratory's science campaigns. Introduces topics including the metallurgical challenge of Plutonium and the use of high performance super-computing to drive design. Addresses the utilization of Abaqus finite element analysis, programmable computer numerical controlled (CNC) machining, as well as glove box ergonomics and safety in order to design a process that will yield high quality Plutonium tensile specimens.

  8. Development of strontium and magnesium substituted porous hydroxyapatite/poly(3,4-ethylenedioxythiophene) coating on surgical grade stainless steel and its bioactivity on osteoblast cells.

    PubMed

    Gopi, D; Ramya, S; Rajeswari, D; Surendiran, M; Kavitha, L

    2014-02-01

    The present study deals with the successful development of bilayer coatings by electropolymerisation of poly(3,4-ethylenedioxythiophene) (PEDOT) on surgical grade stainless steel (316L SS) followed by the electrodeposition of strontium (Sr) and magnesium (Mg) substituted porous hydroxyapatite (Sr, Mg-HA). The bilayer coatings were characterised by Fourier transform infrared spectroscopy (FT-IR) and high resolution scanning electron microscopy (HRSEM). Corrosion resistance of the obtained coatings was investigated in Ringer's solution by electrochemical techniques and the results were in good agreement with those obtained from chemical analysis, namely inductively coupled plasma atomic emission spectrometry (ICP-AES). Also, the mechanical and biological properties of the bilayer coatings were analyzed. From the obtained results it was evident that the PEDOT/Sr, Mg-HA bilayer exhibited greater adhesion strength than the Sr, Mg-HA coated 316L SS. In vitro cell adhesion test of the Sr, Mg-HA coating on PEDOT coated specimen is found to be more bioactive compared to that of the single substituted hydroxyapatite (Sr or Mg-HA) on the PEDOT coated 316L SS. Thus, the PEDOT/Sr, Mg-HA bilayer coated 316L SS can serve as a prospective implant material for biomedical applications. PMID:24200951

  9. Accretion disk structure in SS Cygni

    NASA Astrophysics Data System (ADS)

    Hessman, F. V.

    1987-02-01

    High-resolution coude observations of nonaxisymmetric line emission from the dwarf nova SS Cygni are presented. By subtracting the constant line component, the asymmetric line emission responsible for the observed phase shift between the absorption and emission line radial velocity curves can be isolated. The extra emission is a large fraction of the total line emission and extends to large velocities (of about 1500 km/sec). The phase stability of the emission demands a large-scale structure which is fixed in the frame of the binary. A magnetic origin of the excitation cannot be ruled out but is implausible. A simple explanation is that the accretion stream from the companion star is able to spill over the edge of the disk, introducing emission at noncircular velocities and most likely disturbing the upper layers of the accretion disk.

  10. WFC3 SS UVIS Spare Tungsten Lamp

    NASA Astrophysics Data System (ADS)

    MacKenty, John

    2012-10-01

    Part of side switch activities.This proposal will verify the operation of the spare UVIS channel calsystem tungsten lamp. Internal flatfields will be obtained in one filter from each of the twelve filter wheels, providing an initial baseline and comparison for those taken with the primary lamp {WF09}. Filters for this proposal were chosen based upon a balance of multiple factors: reasonable countrate with calsystem tungsten lamp {no long exposure times}, science priority of the filter, overall coverage of UVIS wavelength regime, and slot location in the wheel. Exposures will be taken in the default full-frame, four-amp, unbinned readout mode.This proposal corresponds to the spare lamp portion of SS SMOV activity ID: WF09b

  11. MULTIWAVELENGTH OBSERVATIONS OF THE SS 433 JETS

    SciTech Connect

    Marshall, Herman L.; Canizares, Claude R.; Schulz, Norbert S.; Nowak, Michael; Hillwig, Todd; Mioduszewski, Amy; Rupen, Michael; Heinz, Sebastian E-mail: crc@space.mit.edu E-mail: mnowak@space.mit.edu E-mail: amiodusz@nrao.edu E-mail: heinzs@astro.wisc.edu

    2013-09-20

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 10{sup 14} cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to ∼> 2 × 10{sup 12} cm. The base jet density is in the range 10{sup 10-13} cm{sup –3}, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  12. Multiwavelength Observations of the SS 433 Jets

    NASA Astrophysics Data System (ADS)

    Marshall, Herman L.; Canizares, Claude R.; Hillwig, Todd; Mioduszewski, Amy; Rupen, Michael; Schulz, Norbert S.; Nowak, Michael; Heinz, Sebastian

    2013-09-01

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 1014 cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to >~ 2 × 1012 cm. The base jet density is in the range 1010-13 cm-3, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  13. Electrothermal fracturing of tensile specimens

    NASA Technical Reports Server (NTRS)

    Blinn, H. O.; Hanks, J. G.; Perkins, H. P.

    1970-01-01

    Pulling device consisting of structural tube, connecting rod, spring-loaded nuts, loading rod, heating element, and three bulkheads fractures tensile specimens. Alternate heating and cooling increases tensile loading by increments until fracturing occurs. Load cell or strain gage, applied to pulling rod, determines forces applied.

  14. An interlaminar tension strength specimen

    NASA Technical Reports Server (NTRS)

    Jackson, Wade C.; Martin, Roderick H.

    1992-01-01

    This paper describes a technique to determine interlaminar tension strength, sigma(sub 3c) of a fiber reinforced composite material using a curved beam. The specimen was a unidirectional curved beam, bent 90 degrees, with straight arms. Attached to each arm was a hinged loading mechanism which was held by the grips of a tensile testing machine. Geometry effects of the specimen, including the effects of loading arm length, inner radius, thickness, and width, were studied. The data sets fell into two categories: low strength corresponding to a macroscopic flaw related failure and high strength corresponding to a microscopic flaw related failure. From the data available, the loading arm length had no effect on sigma(sub 3c). The inner radius was not expected to have a significant effect on sigma(sub 3c), but this conclusion could not be confirmed because of differences in laminate quality for each curve geometry. The thicker specimens had the lowest value of sigma(sub 3c) because of poor laminate quality. Width was found to affect the value of sigma(sub 3c) only slightly. The wider specimens generally had a slightly lower strength since more material was under high stress, and hence, had a larger probability of containing a significant flaw.

  15. An Interlaminar Tensile Strength Specimen

    NASA Technical Reports Server (NTRS)

    Martin, Roderick H.; Jackson, Wade C.

    1993-01-01

    This paper describes a technique to determine interlaminar tensile strength, sigma(sub 3c), of a fiber reinforced composite material using a curved beam. The specimen was a unidirectional curved beam, bent 90 deg, with straight arms. Attached to each arm was a hinged loading mechanism that was held by the grips of a tension testing machine. Geometry effects of the specimen, including the effects of loading arm length, inner radius, thickness, and width, were studied. The data sets fell into two categories: low strength corresponding to a macroscopic flaw related failure and high strength corresponding to a microscopic flaw related failure. From the data available, the specimen width and loading arm length had little effect on sigma(sub 3c). The inner radius was not expected to have a significant effect on sigma(sub 3c), but this conclusion could not be confirmed because of differences in laminate quality for each curve geometry. The thicker specimens had the lowest value of sigma(sub 3c) because of poor laminate quality.

  16. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disk material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  17. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disc material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  18. EBSD analysis of magnesium addition on inclusion formation in SS400 structural steel

    SciTech Connect

    Luo, Sin-Jie; Su, Yen-Hao Frank; Lu, Muh-Jung; Kuo, Jui-Chao

    2013-08-15

    In this study, the effect of magnesium addition on the inclusion formation in SS400 steel was investigated. The experimental specimens with and without Mg addition treatment were compared. The microstructure was observed using optical microscopy after etching with 3% nital. The morphology and chemical composition of the inclusions were analyzed via scanning electron microscopy and energy dispersive spectrometry. The lattice structure and orientation of the inclusions were identified by electron backscattering diffraction. The average size of inclusions in SS400 was between 0.67 and 0.75 μm, and between 0.65 and 0.68 μm in SS400 + Mg. The 2 ppm Mg addition resulted in the oxide formation change from Al{sub 2}O{sub 3} to MgO·Al{sub 2}O{sub 3} and in the inclusion formation change from Al{sub 2}O{sub 3}–MnS to MgO·Al{sub 2}O{sub 3}–MnS. Moreover, a simple-phase MnS with an average grain size of 1 μm to 2 μm was observed in rod-like, globular, and polyhedron forms. - Highlights: • The effect of magnesium addition was investigated for SS400 steel. • 2 ppm Mg addition changes the inclusion formation from Al2O3-MnS to MgO·Al2O3-MnS. • MnS observed in inclusions exhibits rod-like, globular, and polyhedron forms.

  19. Mechanochemical regulations of RPA's binding to ssDNA

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J.; Yan, Jie

    2015-03-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA.

  20. Mechanochemical regulations of RPA's binding to ssDNA.

    PubMed

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J; Yan, Jie

    2015-01-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA. PMID:25787788

  1. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  2. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  3. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  4. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  5. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  6. SS1 (NAL1)- and SS2-Mediated Genetic Networks Underlying Source-Sink and Yield Traits in Rice (Oryza sativa L.)

    PubMed Central

    Wu, Yuan; Zheng, Tian-Qing; Wang, Yong-Hong; Zhao, Xiu-Qin; Cui, Yan-Ru; Chen, Kai; Zhang, Qiang; Lin, Hong-Xuan; Li, Jia-Yang; Li, Zhi-Kang

    2015-01-01

    Source leaf/sink capacity (SS) traits are important determinants of grain yield (GY) of rice. To understand the genetic basis of the SS relationship in rice, five SS and GY traits of rice were genetically dissected using two reciprocal introgression populations. Seventy-three QTL affecting the SS and GY traits were identified, most of which were detected in one of the parental genetic backgrounds (GBs). Two major QTL at bins 4.7 (SS1) and 3.12 (SS2) were associated consistently with all measured SS and yield traits in both GBs across two contrasting environments. Strong interactions between SS1/SS2 and the detected QTL led us to the discovery of genetic networks affecting the SS and GY traits. The SS1 acted as a regulator controlling two groups of downstream QTL affecting the source leaf width and grain number per panicle (GNP). SS2 functioned as a regulator positively regulating different groups of downstream QTL affecting the source leaf length, GNP, grain weight, and GY. Map-based cloning of SS1 indicates that SS1 is NAL1 involved in polar auxin/IAA transport. Different alleles at NAL1 were apparently able to qualitatively and/or quantitatively control the IAA transport from the apical meristem to different plant tissues and thus regulate those downstream loci/pathways controlling different SS traits of rice. There was a functional allele and a non-functional mutation in the parents at each of the QTL downstream of SS1 or SS2, which were detectable only in the presence of the functional allele of SS1 or SS2. Our results provided direct evidence that SS and yield traits in rice are controlled by complex signaling pathways and suggest further improvement of rice yield potential with enhanced and balanced SS relationships can be achieved by accurately manipulating allelic combinations at loci in the SS1 and SS2 mediated pathways. PMID:26162098

  7. 10 CFR 26.165 - Testing split specimens and retesting single specimens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... single specimens. (a) Testing split specimens. (1) If a specimen has been split into Bottle A and Bottle... required, of the specimen in Bottle A. (2) If a specimen was initially tested at a licensee testing... laboratory shall perform initial and confirmatory testing, if required, of the specimen in Bottle A. (3)...

  8. 10 CFR 26.165 - Testing split specimens and retesting single specimens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... single specimens. (a) Testing split specimens. (1) If a specimen has been split into Bottle A and Bottle... required, of the specimen in Bottle A. (2) If a specimen was initially tested at a licensee testing... laboratory shall perform initial and confirmatory testing, if required, of the specimen in Bottle A. (3)...

  9. Embedded algorithms for the SS-411 digital sun sensor

    NASA Astrophysics Data System (ADS)

    Enright, John; Sinclair, Doug; Li, Chris

    2009-05-01

    This paper discusses the evolution of the SS-411 series digital sun sensor. The earlier SS-256 and SS-330 models have proven themselves in orbit on low-cost satellite missions. The SS-411 represents a further hardware revision with enhanced robustness and improved attitude estimation performance. To complement the latest hardware improvements, researchers in the Space Avionics and Instrumentation Laboratory (SAIL) at Ryerson University in Toronto have developed advanced signal processing routines compatible with the SS-411. These routines significantly improve the accuracy of the sensor's estimation without increasing manufacturing complexity. With this advanced processing, the sensor maintains a 2-σ accuracy of 0.11° over the entire field-of-view.

  10. Baseline Test Specimen Machining Report

    SciTech Connect

    mark Carroll

    2009-08-01

    The Next Generation Nuclear Plant (NGNP) Project is tasked with selecting a high temperature gas reactor technology that will be capable of generating electricity and supplying large amounts of process heat. The NGNP is presently being designed as a helium-cooled high temperature gas reactor (HTGR) with a large graphite core. The graphite baseline characterization project is conducting the research and development (R&D) activities deemed necessary to fully qualify nuclear-grade graphite for use in the NGNP reactor. Establishing nonirradiated thermomechanical and thermophysical properties by characterizing lot-to-lot and billet-to-billet variations (for probabilistic baseline data needs) through extensive data collection and statistical analysis is one of the major fundamental objectives of the project. The reactor core will be made up of stacks of graphite moderator blocks. In order to gain a more comprehensive understanding of the varying characteristics in a wide range of suitable graphites, any of which can be classified as “nuclear grade,” an experimental program has been initiated to develop an extensive database of the baseline characteristics of numerous candidate graphites. Various factors known to affect the properties of graphite will be investigated, including specimen size, spatial location within a graphite billet, specimen orientation within a billet (either parallel to [P] or transverse to [T] the long axis of the as-produced billet), and billet-to-billet variations within a lot or across different production lots. Because each data point is based on a certain position within a given billet of graphite, particular attention must be paid to the traceability of each specimen and its spatial location and orientation within each billet. The evaluation of these properties is discussed in the Graphite Technology Development Plan (Windes et. al, 2007). One of the key components in the evaluation of these graphite types will be mechanical testing on

  11. Appendix A: Specimen 72275 documentation

    NASA Technical Reports Server (NTRS)

    Marvin, U. B.

    1974-01-01

    The friability of the matrix of specimen 72275 caused numerous fragments and an abundance of fines to break away from the main mass during transport from the moon and handling in the lunar receiving laboratory. Samples 72275,1 to 72275,14 were labeled during PET examination. Samples 72275,1, 4, 6, 7, 8, and 9 were placed in storage, and the remainder were distributed.

  12. Eccentric loading of microtensile specimens

    NASA Technical Reports Server (NTRS)

    Trapp, Mark A.

    2004-01-01

    Ceramic materials have a lower density than most metals and are capable of performing at extremely high temperatures. The utility of these materials is obvious; however, the fracture strength of brittle materials is not easily predicted and often varies greatly. Characteristically, brittle materials lack ductility and do not yield as other materials. Ceramics materials are naturally populated with microscopic cracks due to fabrication techniques. Upon application of a load, stress concentration occurs at the root of these cracks and fracture will eventually occur at some not easily predicted strength. In order to use ceramics in any application some design methodology must exist from which a component can be placed into service. This design methodology is CARES/LIFE (Ceramics Analysis and Reliability Evaluation of Structures) which has been developed and refined at NASA over the last several decades. The CARES/LIFE computer program predicts the probability of failure of a ceramic component over its service life. CARES combines finite element results from a commercial FE (finite element) package such as ANSYS and experimental results to compute the abovementioned probability of failure. Over the course of several tests CARES has had great success in predicting the life of various ceramic components and has been used throughout industry. The latest challenge is to verify that CARES is valid for MEMS (Micro-Electro Mechanical Systems). To investigate a series of microtensile specimens were fractured in the laboratory. From this data, material parameters were determined and used to predict a distribution of strength for other specimens that exhibit a known stress concentration. If the prediction matches the experimental results then these parameters can be applied to a desired component outside of the laboratory. During testing nearly half of the tensile Specimens fractured at a location that was not expected and hence not captured in the FE model. It has been my duty

  13. Compound Charpy specimens by adhesive joining

    NASA Astrophysics Data System (ADS)

    Ghoneim, M. M.; Hammad, F. H.; Pachur, D.; Britz, L.

    1992-03-01

    Compound (reconstituted) Charpy specimens were manufactured by an adhesive joining method in which each half of a previously tested specimen formed the central section of a new testpiece. 29 adhesives were screened to select the most suitable. Compound specimens were precracked and used as minature fracture mechanics specimens and tested in both 3-point static bending and impact. The results are in good agreement with those of conventional specimens. Recommendations for the most appropriate commercial adhesive for hot cell operations are given.

  14. A substitute for BOC modulation based on SS-CPM

    NASA Astrophysics Data System (ADS)

    Su, Chengeng; Guo, Shuren; Zhou, Hongwei

    2013-03-01

    CPM (continuous phase modulation) has been widely used in the field of satellite communication, which has high spectrum efficiency and constant envelope. This paper explores the applicability of CPM to satellite navigation. A SS-CPM (Spread-Spectrum CPM) modulation is investigated. The SS-CPM with tuned parameters can resemble the spectrum of Binary Offset Carrier (BOC) modulation and yields comparable performance in terms of tracking accuracy, multipath mitigation, anti-jamming, and compatibility. The BOC-like SS-CPM signal maintains the constant envelope at transmission and less out-band emission in radio determination satellite service (RDSS) band, which provides a reference modulation for COMPASS satellite navigation signal.

  15. Multiphoton microspectroscopy of biological specimens

    NASA Astrophysics Data System (ADS)

    Lin, Bai-Ling; Kao, Fu-Jen; Cheng, Ping C.; Sun, Chi-Kuang; Chen, RangWu; Wang, YiMin; Chen, JianCheng; Wang, Yung-Shun; Liu, Tzu-Ming; Huang, Mao-Kuo

    2000-07-01

    The non-linear nature of multi-photon fluorescence excitation restricts the fluorescing volume to the vicinity of the focal point. As a result, the technology has the capacity for micro- spectroscopy of biological specimen at high spatial resolution. Chloroplasts in mesophyll protoplast of Arabidopsis thaliana and maize stem sections were used to demonstrate the feasibility of multi-photon fluorescence micro-spectroscopy at subcellular compartments. Time-lapse spectral recording provides a means for studying the response of cell organelles to high intensity illumination.

  16. 1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. PETER & PAUL'S JESUIT CHURCH, DETROIT MICHIGAN - Sts. Peter & Paul's Jesuit Church, East Jefferson Avenue & Saint Antoine Street, Detroit, MI

  17. Automated Tracking of Drosophila Specimens

    PubMed Central

    Chao, Rubén; Macía-Vázquez, Germán; Zalama, Eduardo; Gómez-García-Bermejo, Jaime; Perán, José-Ramón

    2015-01-01

    The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained. PMID:26258779

  18. Automated Tracking of Drosophila Specimens.

    PubMed

    Chao, Rubén; Macía-Vázquez, Germán; Zalama, Eduardo; Gómez-García-Bermejo, Jaime; Perán, José-Ramón

    2015-01-01

    The fruit fly Drosophila Melanogaster has become a model organism in the study of neurobiology and behavior patterns. The analysis of the way the fly moves and its behavior is of great scientific interest for research on aspects such as drug tolerance, aggression or ageing in humans. In this article, a procedure for detecting, identifying and tracking numerous specimens of Drosophila by means of computer vision-based sensing systems is presented. This procedure allows dynamic information about each specimen to be collected at each moment, and then for its behavior to be quantitatively characterized. The proposed algorithm operates in three main steps: a pre-processing step, a detection and segmentation step, and tracking shape. The pre-processing and segmentation steps allow some limits of the image acquisition system and some visual artifacts (such as shadows and reflections) to be dealt with. The improvements introduced in the tracking step allow the problems corresponding to identity loss and swaps, caused by the interaction between individual flies, to be solved efficiently. Thus, a robust method that compares favorably to other existing methods is obtained. PMID:26258779

  19. Hydraulically Driven Grips For Hot Tensile Specimens

    NASA Technical Reports Server (NTRS)

    Bird, R. Keith; Johnson, George W.

    1994-01-01

    Pair of grips for tensile and compressive test specimens operate at temperatures up to 1,500 degrees F. Grips include wedges holding specimen inside furnace, where heated to uniform temperature. Hydraulic pistons drive wedges, causing them to exert clamping force. Hydraulic pistons and hydraulic fluid remain outside furnace, at room temperature. Cooling water flows through parts of grips to reduce heat transferred to external components. Advantages over older devices for gripping specimens in high-temperature tests; no need to drill holes in specimens, maintains constant gripping force on specimens, and heated to same temperature as that of specimen without risk of heating hydraulic fluid and acuator components.

  20. Human bulbar conjunctival hemodynamics in hemoglobin SS and SC disease

    PubMed Central

    Wanek, Justin; Gaynes, Bruce; Lim, Jennifer I.; Molokie, Robert; Shahidi, Mahnaz

    2014-01-01

    The known biophysical variations of hemoglobin (Hb) S and Hb C may result in hemodynamic differences between subjects with SS and SC disease. The purpose of this study was to measure and compare conjunctival hemodynamics between subjects with Hb SS and SC hemoglobinopathies. Image sequences of the conjunctival microcirculation were acquired in 9 healthy control subjects (Hb AA), 24 subjects with SC disease, and 18 subjects with SS disease, using a prototype imaging system. Diameter (D) and blood velocity (V) measurements were obtained in multiple venules of each subject. Data were categorized according to venule caliber by averaging V and D for venules with diameters less than (vessel size 1) or greater than (vessel size 2) 15 µm. V in vessel size 2 was significantly greater than V in vessel size 1 in the AA and SS groups (P ≥ 0.009), but not in the SC group (P = 0.1). V was significantly lower in the SC group as compared to the SS group (P = 0.03). In AA and SS groups, V correlated with D (P ≥ 0.005), but the correlation was not statistically significant in the SC group (P = 0.08). V was inversely correlated with hematocrit in the SS group for large vessels (P = 0.03); however, no significant correlation was found in the SC group (P ≥ 0.2). Quantitative assessment of conjunctival microvascular hemodynamics in SS and SC disease may advance understanding of sickle cell disease pathophysiology and thereby improve therapeutic interventions. PMID:23657867

  1. The Spectral Components of SS 433

    NASA Astrophysics Data System (ADS)

    Gies, D. R.; McSwain, M. V.; Riddle, R. L.; Wang, Z.; Wiita, P. J.; Wingert, D. W.

    2002-02-01

    We present results from new optical and UV spectroscopy of the unusual binary system SS 433, and we discuss the relationship of the particular spectral components that we observe to the properties of the binary. These spectral components include1. The continuum spectrum, which we associate with flux from the super-Eddington accretion disk and the dense part of its wind. A far-UV spectrum from the Hubble Space Telescope Space Telescope Imaging Spectrograph made during the edge-on orientation of the disk places an upper limit on the temperature of an equivalent blackbody source (T<21,000 K for AV=7.8) when combined with near-UV and optical fluxes. The continuum source has an effective projected radius of approximately half the binary separation, so that the source may be larger than the Roche radius of the compact star.2. Hα moving components, which are formed far from the binary orbital plane in the relativistic jets. We confirm that these emission features appear as ``bullets'' at a fixed wavelength and may last for a few days. We present a contemporary radial velocity curve for the precessional motion of the jets that includes the nodding motion caused by tidal interaction with the optical star.3. Hα and He I ``stationary'' emission lines, which we suggest are formed in the disk wind in a volume larger than the dimensions of the binary. These lines vary on all timescales and sometimes appear as P Cygni lines. We suggest that their radial velocity curves (which show greatest redshift at inferior conjunction of the optical star) result from an evacuation of the disk wind surrounding the optical star (caused by physical blockage, heating, or colliding winds). We argue that the wake of this interaction region causes an extended eclipse of the X-ray source (as seen in Rossi X-Ray Timing Explorer All-Sky Monitor light curves).4. A weak ``stationary'' emission feature, which we identify as a C II λλ7231, 7236 blend that attains maximum radial velocity at the orbital

  2. Nano-cavities observed in a 316SS PWR Flux Thimble Tube Irradiated to 33 and 70 dpa

    SciTech Connect

    Edwards, Danny J.; Garner, Francis A.; Bruemmer, Stephen M.; Efsing, Pal G.

    2009-02-28

    The radiation-induced microstructure of a cold-worked 316SS flux thimble tube from an operating pressurized water reactor (PWR) was examined. Two irradiated conditions, 33 dpa at 290ºC and 70 dpa at 315ºC were examined by transmission electron microscopy. The original dislocation network had completely disappeared and was replaced by fine dispersions of Frank loops and small nano-cavities at high densities. The latter appear to be bubbles containing high levels of helium and hydrogen. An enhanced distribution of these nano-cavities was found at grain boundaries and may play a role in the increased susceptibility of the irradiated 316SS to intergranular failure of specimens from this tube during post-irradiation slow strain rate testing in PWR water conditions.

  3. 37 CFR 2.56 - Specimens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.56 Specimens. (a) An application under section 1(a) of..., is acceptable. However, a photocopy of the drawing required by § 2.51 is not a proper specimen....

  4. 37 CFR 2.56 - Specimens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... RULES OF PRACTICE IN TRADEMARK CASES Drawing § 2.56 Specimens. (a) An application under section 1(a) of..., is acceptable. However, a photocopy of the drawing required by § 2.51 is not a proper specimen....

  5. Testing Biopsy and Cytology Specimens for Cancer

    MedlinePlus

    ... articles window. My Saved Articles » My ACS » Testing Biopsy and Cytology Specimens for Cancer Download Printable Version [ ... on the topics below to get started. Testing Biopsy and Cytology Specimens for Cancer How is cancer ...

  6. Details of ssDNA annealing revealed by an HSV-1 ICP8–ssDNA binary complex

    PubMed Central

    Tolun, Gökhan; Makhov, Alexander M.; Ludtke, Steven J.; Griffith, Jack D.

    2013-01-01

    Infected cell protein 8 (ICP8) from herpes simplex virus 1 was first identified as a single-strand (ss) DNA-binding protein. It is essential for, and abundant during, viral replication. Studies in vitro have shown that ICP8 stimulates model replication reactions, catalyzes annealing of complementary ssDNAs and, in combination with UL12 exonuclease, will catalyze ssDNA annealing homologous recombination. DNA annealing and strand transfer occurs within large oligomeric filaments of ssDNA-bound ICP8. We present the first 3D reconstruction of a novel ICP8–ssDNA complex, which seems to be the basic unit of the DNA annealing machine. The reconstructed volume consists of two nonameric rings containing ssDNA stacked on top of each other, corresponding to a molecular weight of 2.3 MDa. Fitting of the ICP8 crystal structure suggests a mechanism for the annealing reaction catalyzed by ICP8, which is most likely a general mechanism for protein-driven DNA annealing. PMID:23605044

  7. Reweldability test of irradiated SS316 by the TIG welding method

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kunihiko; Kawamura, Hiroshi; Oyamada, Rokuro

    1996-10-01

    Stainless steel is a candidate material for the structural material in fusion reactors. Rewelding of irradiated materials will have a large impact on the design and the maintenance of in-vessel components. In the present work, the welding specimens made of type 316 stainless steel were irradiated in JMTR (Japan materials testing reactor) to a fast neutron fluence of ˜2.0 × 10 20 n/cm 2 ( E > 1 MeV) at a temperature of ˜200°C. The rewelding of unirradiated and/or irradiated stainless steel was performed by the tungsten inert gas (TIG) welding method and the weldments of unirradiated and/or irradiated SS316 were characterized by tensile testing (test temp.: 20°C and 200°C), hardness, metallographical observation and SEM/XMA analyses.

  8. Apparatus for automated testing of biological specimens

    DOEpatents

    Layne, Scott P.; Beugelsdijk, Tony J.

    1999-01-01

    An apparatus for performing automated testing of infections biological specimens is disclosed. The apparatus comprise a process controller for translating user commands into test instrument suite commands, and a test instrument suite comprising a means to treat the specimen to manifest an observable result, and a detector for measuring the observable result to generate specimen test results.

  9. Specimen mass measurement. [during space environment simulation

    NASA Technical Reports Server (NTRS)

    Thornton, W. E.; Ord, J.

    1973-01-01

    The Skylab specimen mass measurement device was operated throughout the altitude test in close simulation of the 56-day Skylab mission. It performed operational specimen measurements well until it was passed out of the chamber for replacement of the specimen hold-down and was autoclaved prior to return. Fecal measurements were typically made with less than one percent error.

  10. 10 CFR 26.135 - Split specimens.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Split specimens. 26.135 Section 26.135 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.135 Split specimens. (a) If the FFD program follows split-specimen procedures, as described in § 26.113, the licensee...

  11. 10 CFR 26.135 - Split specimens.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Split specimens. 26.135 Section 26.135 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.135 Split specimens. (a) If the FFD program follows split-specimen procedures, as described in § 26.113, the licensee...

  12. 10 CFR 26.135 - Split specimens.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Split specimens. 26.135 Section 26.135 Energy NUCLEAR REGULATORY COMMISSION FITNESS FOR DUTY PROGRAMS Licensee Testing Facilities § 26.135 Split specimens. (a) If the FFD program follows split-specimen procedures, as described in § 26.113, the licensee...

  13. 50 CFR 14.24 - Scientific specimens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 1 2013-10-01 2013-10-01 false Scientific specimens. 14.24 Section 14.24....24 Scientific specimens. Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts...

  14. 50 CFR 14.24 - Scientific specimens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 1 2014-10-01 2014-10-01 false Scientific specimens. 14.24 Section 14.24....24 Scientific specimens. Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts...

  15. 50 CFR 14.24 - Scientific specimens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false Scientific specimens. 14.24 Section 14.24....24 Scientific specimens. Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts...

  16. 50 CFR 14.24 - Scientific specimens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 1 2012-10-01 2012-10-01 false Scientific specimens. 14.24 Section 14.24....24 Scientific specimens. Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts...

  17. 50 CFR 14.24 - Scientific specimens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Scientific specimens. 14.24 Section 14.24....24 Scientific specimens. Except for wildlife requiring a permit pursuant to parts 16, 17, 18, 21, 22 or 23 of this subchapter, dead, preserved, dried, or embedded scientific specimens or parts...

  18. Corrosion Fatigue Behavior of 316LN SS in Acidified Sodium Chloride Solution at Applied Potential

    NASA Astrophysics Data System (ADS)

    Poonguzhali, A.; Pujar, M. G.; Mallika, C.; Mudali, U. Kamachi

    2015-05-01

    The influence of acidified 1 M NaCl solution by addition of 2 ml/L of HCl on the cyclic plastic deformation of AISI Type 316LN SS containing 0.07 wt.% and 0.22 wt.% N was investigated as a function of the applied potentials. The corrosion fatigue (CF) behavior of stainless steel (SS) was explained vis-a-vis the dislocation behavior, the propensity to form microcracks, and the evolution of the current transients based on the studies carried out at both room-temperature and boiling conditions. CF experiments were conducted using round tensile specimens at a stress ratio of 0.5 and a frequency of 0.1 Hz. Two different kinds of damage mechanisms were observed (I) the damage mechanism in the stable-passive state was correlated with the localization of the anodic dissolution due to a depassivation-repassivation process, whereas (II) the cyclic stress induced pitting corrosion in the metastable pitting state, which resulted in formation of microcracks. The study of the microcracking process and its evolution is a key to the physical mechanism by which the fatigue life of stainless steels would be affected in an aqueous corrosive solution under the applied potential.

  19. A novel approach to managing hemolyzed specimens.

    PubMed

    Pretlow, Lester; Johnson, Shamala; Russell, Barbara; Evans, Bridget

    2013-01-01

    Hemolyzed specimens continue to cost the laboratory time and money. However, the core laboratory at Georgia Regents Health System, Inc. has instituted a novel approach to managing this problem. The purpose of this study was to determine whether the laboratory's new approach had a significant impact on the turn-around time (TAT) and cost of processing hemolyzed and non-hemolyzed specimens in the laboratory. The investigators queried the laboratory information systems for hemolyzed and non-hemolyzed specimens categorized as routine or STAT from the core laboratory and calculated statistical differences between the groups with respect to TAT and cost.The investigators found a statistically significant difference in the time it takes to process STAT hemolyzed specimens versus non-hemolyzed specimens with the new approach. Because of the new approach, hemolyzed specimens were actually processed as fast as, or faster than non-hemolyzed specimens in the core laboratory. PMID:23967544

  20. Performance of DMFC with SS 316 bipolar/end plates

    NASA Astrophysics Data System (ADS)

    Padhy, Biswa R.; Reddy, Ramana G.

    This work mainly emphasizes the development of new materials and design for a bipolar/end plate in a direct methanol fuel cell (DMFC). According to the DOE requirements, preliminary studies show that SS 316 (Stainless Steel 316) is a suitable candidate. Several flow field designs were studied and a modified serpentine design was proposed. SS 316 end plates were fabricated with an intricate modified serpentine flow field design on it. The performance of a single stack DMFC with SS 316 end plates were studied with different operational parameters. A long-term test was carried out for 100 h with recycling the methanol and the contaminants in the MEA were characterized. The stack efficiency is found to be 51% and polarization losses are discussed. SS 316 with low permeability resulted in an increased pressure drop across the flow field, which increased the fuel cell performance. The use of SS 316 as bipolar plate material will reduce the machining cost as well as volume of the fuel cell stack.

  1. On the Nature of Compact Object in SS~433. An Observational Evidence of Black Hole Mass in SS 433

    NASA Astrophysics Data System (ADS)

    Titarchuk, Lev

    We present an analysis of X-ray spectral properties observed from black hole candidate (BHC) binary SS 433. We analyze RXTE data from this source, coordinated with Green Bank Interferometer/RATAN-600. We show that SS 433 demonstrates a X-ray spectral transition from low hard state to intermediate state (IS). We show that the X-ray broad-band energy spectra during all spectral states are well fit by a sum of so called "Bulk Motion Comptoniza-tion (BMC)" component and by two (broad and narrow) Gaussians for the continuum and line emissions respectively. In addition to these spectral model components we also find a strong feature of "blackbody-like (BB)" bump which color temperature is in the range of 4-5 keV in 24 IS spectra during radio outburst decay in SS 433. Our observational results on the "high temperature BB" bump leads us to support the presence of gravitationally redshifted annihila-tion lines in this source. We also established the photon index saturation at about 2.3 in index vs mass accretion correlation. This index-mass accretion correlation allows us to evaluate the low limit of black hole (BH) mass of compact object in SS 433, greater than 2 solar masses, using the scaling method using BHC GX 339-4 as a reference source. Our estimate of BH mass in SS 433 is consistent with the recent BH mass measurement by Hillwig Gies who find that BH mass about 4.3 solar masses. It is the smallest BH mass up to now found among all BHC sources where BH masses have been estimated so far. Moreover, the index saturation effect versus mass accretion rate revealed in SS 433, like in a number of other BHCs, is the strongest observational evidence of the presence of BH in SS 433.

  2. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  3. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  4. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  5. 78 FR 23981 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  6. 75 FR 10017 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  7. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  8. 27 CFR 24.47 - Execution of IRS Form SS-4.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Execution of IRS Form SS-4... Number § 24.47 Execution of IRS Form SS-4. (a) Preparation. The application on IRS Form SS-4, together... center as instructed on the Form SS-4. (b) Signature. The application will be signed by: (1)...

  9. [The German Environmental Specimen Bank].

    PubMed

    Schröter-Kermani, Christa; Gies, Andreas; Kolossa-Gehring, Marike

    2016-03-01

    The main objective of the German Environmental Specimen Bank (ESB) is the long-term storage of environmental and human samples under stable deep-freeze conditions for future research. The ESB is unique in providing a continuous historical record of environmental and human exposure to chemicals in Germany. ESB was started parallel to the development of the first German Chemicals Legislation in the late 1970s. In 1979, the ESB test operation began. After the Chemicals Law came into force in 1982, the ESB was established as a permanent facility in 1985. With the new European Chemicals Legislation, REACH, in 2007 responsibility for the safety of commercial chemicals and risk assessment was assigned to the industry. Since then, the ESB has become even more important in verifying the self-assessment of the industry, in evaluating the effectiveness of regulations, thus ensuring the protection of humans and the environment against adverse effects caused by exposure to chemicals. These objectives are pursued by the regular monitoring of contaminations and the assessment of temporal trends. Demonstrating the necessity of deriving exposure reduction measures, ESB results serve as key information for policy-makers. Information on preventing exposure to chemicals is available to the general public and to the public health services. The ESB is thus an important monitoring instrument of the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety. The Federal Environment Agency operates the ESB based on its own concepts, heads the scientific data evaluation and transfers results into the environmental policy arena and to the general public. PMID:26753867

  10. e-VLBI observations of SS 433 in outburst

    NASA Astrophysics Data System (ADS)

    Tudose, V.; Paragi, Z.; Trushkin, S.; Soleri, P.; Fender, R.; Garrett, M.; Spencer, R.; Rushton, A.; Burgess, P.; Kunert-Bajraszewska, M.; Pazderski, E.; Borkowski, K.; Hammargren, R.; Lindqvist, M.; Maccaferri, G.

    2008-11-01

    We have observed the X-ray binary SS 433 on November 6, 2008 between 13:48-18:35 UT at 5 GHz with the European VLBI Network (EVN) using the e-VLBI technique. The radio telescopes participating in the experiment were: Medicina, Onsala 25m, Torun, Jodrell Bank MkII and Cambridge. The X-ray binary SS 433 is in outburst. Trushkin & Nizhelskij (ATel #1819) reported a major flare already active during the RATAN-600 observations in the 1-22 GHz band on 2008 October 28.

  11. The spotted contact binary SS ARIETIS - Spectroscopy and infrared photometry

    NASA Astrophysics Data System (ADS)

    Rainger, P. P.; Bell, S. A.; Hilditch, R. W.

    1992-02-01

    The first infrared photometry for the W-UMa system SS Ari is presented. An analysis based on medium-resolution spectroscopy presented here shows that SS Ari is a W-type system with a mass ratio of 0.33. It seems certain that the asymmetry in the published light curves and those obtained for this study can be explained by the effect of spots on one or possibly both components of the system. The precise location, size and temperature of these spots require the use of Doppler Imaging techniques in conjunction with high-quality multiband photometry.

  12. NEET-AMM Final Technical Report on Laser Direct Manufacturing (LDM) for Nuclear Power Components

    SciTech Connect

    Anderson, Scott; Baca, Georgina; O'Connor, Michael

    2015-12-31

    Final technical report summarizes the program progress and technical accomplishments of the Laser Direct Manufacturing (LDM) for Nuclear Power Components project. A series of experiments varying build process parameters (scan speed and laser power) were conducted at the outset to establish the optimal build conditions for each of the alloys. Fabrication was completed in collaboration with Quad City Manufacturing Laboratory (QCML). The density of all sample specimens was measured and compared to literature values. Optimal build process conditions giving fabricated part densities close to literature values were chosen for making mechanical test coupons. Test coupons whose principal axis is on the x-y plane (perpendicular to build direction) and on the z plane (parallel to build direction) were built and tested as part of the experimental build matrix to understand the impact of the anisotropic nature of the process.. Investigations are described 316L SS, Inconel 600, 718 and 800 and oxide dispersion strengthed 316L SS (Yttria) alloys.

  13. Standardizing the Handling of Surgical Specimens.

    PubMed

    Shirey, Cheryl; Perrego, Kristen

    2015-11-01

    To standardize the handling of surgical specimens, the OR clinical educators in a community hospital setting devised a series of departmental changes as a quality improvement project. A newly created skill validation was reviewed in an hour-long educational meeting with all OR staff members. In addition to creating a new annual skill validation, discussions about specimens were included in the hand over, the time out, and a newly instituted debriefing tool to be used toward the end of a procedure. This interdisciplinary group devised interventions to improve the process of handling specimens such as standardizing the labeling process and changing the transparency of the specimen container. The goal was to assure standardization of specimen handling, specifically to assist novice staff members, and to harmonize inconsistencies between specialties within the practice of existing staff members. These combined methods helped to ensure accurate communication and procurement of specimens for all procedures. PMID:26514715

  14. Flat tensile specimen design for advanced composites

    NASA Technical Reports Server (NTRS)

    Worthem, Dennis W.

    1990-01-01

    Finite element analyses of flat, reduced gage section tensile specimens with various transition region contours were performed. Within dimensional constraints, such as maximum length, tab region width, gage width, gage length, and minimum tab length, a transition contour radius of 41.9 cm produced the lowest stress values in the specimen transition region. The stresses in the transition region were not sensitive to specimen material properties. The stresses in the tab region were sensitive to specimen composite and/or tab material properties. An evaluation of stresses with different specimen composite and tab material combinations must account for material nonlinearity of both the tab and the specimen composite. Material nonlinearity can either relieve stresses in the composite under the tab or elevate them to cause failure under the tab.

  15. Identification of ssDNA aptamers specific to clinical isolates of Streptococcus mutans strains with different cariogenicity.

    PubMed

    Cui, Wei; Liu, Jiaojiao; Su, Donghua; Hu, Danyang; Hou, Shuai; Hu, Tongnan; Yang, Jiyong; Luo, Yanping; Xi, Qing; Chu, Bingfeng; Wang, Chenglong

    2016-06-01

    Streptococcus mutans, a Gram-positive facultative anaerobic bacterium, is considered to be a major etiological factor for dental caries. In this study, plaques from dental enamel surfaces of caries-active and caries-free individuals were obtained and cultivated for S. mutans isolation. Morphology examination, biochemical characterization, and polymerase chain reaction were performed to identify S. mutans The cariogenicity of S. mutans strains isolated from clinical specimens was evaluated by testing the acidogenicity, aciduricity, extracellular polysaccharide production, and adhesion ability of the bacteria. Finally, subtractive SELEX (systematic evolution of ligands by exponential enrichment) technology targeting whole intact cells was used to screen for ssDNA aptamers specific to the strains with high cariogenicity. After nine rounds of subtractive SELEX, sufficient pool enrichment was achieved as shown by radioactive isotope analysis. The enriched pool was cloned and sequenced randomly, followed by MEME online and RNA structure software analysis of the sequences. Results from the flow cytometry indicated that aptamers H1, H16, H4, L1, L10, and H19 could discriminate highly cariogenic S. mutans strains from poorly cariogenic strains. Among these, Aptamer H19 had the strongest binding capacity with cariogenic S. mutans strains with a dissociation constant of 69.45 ± 38.53 nM. In conclusion, ssDNA aptamers specific to highly cariogenic clinical S. mutans strains were successfully obtained. These ssDNA aptamers might be used for the early diagnosis and treatment of dental caries. PMID:27151293

  16. NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-05-07

    NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA Project Title:  NARSTO ... Amount Surface Pressure Solar Radiation Surface Air Temperature Particulates Trace Metals Order Data:  ... Data Guide Documents:  St Louis Air Chem Guide St Louis Final Report  (PDF) St Louis QA ...

  17. NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA Project Title:  NARSTO ... Thermooptical Transmission Location:  New York Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  New York Air Chem Guide CPM Summary Report  (PDF) ...

  18. RPA homologs and ssDNA processing during meiotic recombination.

    PubMed

    Ribeiro, Jonathan; Abby, Emilie; Livera, Gabriel; Martini, Emmanuelle

    2016-06-01

    Meiotic homologous recombination is a specialized process that involves homologous chromosome pairing and strand exchange to guarantee proper chromosome segregation and genetic diversity. The formation and repair of DNA double-strand breaks (DSBs) during meiotic recombination differs from those during mitotic recombination in that the homologous chromosome rather than the sister chromatid is the preferred repair template. The processing of single-stranded DNA (ssDNA) formed on intermediate recombination structures is central to driving the specific outcomes of DSB repair during meiosis. Replication protein A (RPA) is the main ssDNA-binding protein complex involved in DNA metabolism. However, the existence of RPA orthologs in plants and the recent discovery of meiosis specific with OB domains (MEIOB), a widely conserved meiosis-specific RPA1 paralog, strongly suggest that multiple RPA complexes evolved and specialized to subdivide their roles during DNA metabolism. Here we review ssDNA formation and maturation during mitotic and meiotic recombination underlying the meiotic specific features. We describe and discuss the existence and properties of MEIOB and multiple RPA subunits in plants and highlight how they can provide meiosis-specific fates to ssDNA processing during homologous recombination. Understanding the functions of these RPA homologs and how they interact with the canonical RPA subunits is of major interest in the fields of meiosis and DNA repair. PMID:26520106

  19. KInNeSS: a modular framework for computational neuroscience.

    PubMed

    Versace, Massimiliano; Ames, Heather; Léveillé, Jasmin; Fortenberry, Bret; Gorchetchnikov, Anatoli

    2008-01-01

    Making use of very detailed neurophysiological, anatomical, and behavioral data to build biologically-realistic computational models of animal behavior is often a difficult task. Until recently, many software packages have tried to resolve this mismatched granularity with different approaches. This paper presents KInNeSS, the KDE Integrated NeuroSimulation Software environment, as an alternative solution to bridge the gap between data and model behavior. This open source neural simulation software package provides an expandable framework incorporating features such as ease of use, scalability, an XML based schema, and multiple levels of granularity within a modern object oriented programming design. KInNeSS is best suited to simulate networks of hundreds to thousands of branched multi-compartmental neurons with biophysical properties such as membrane potential, voltage-gated and ligand-gated channels, the presence of gap junctions or ionic diffusion, neuromodulation channel gating, the mechanism for habituative or depressive synapses, axonal delays, and synaptic plasticity. KInNeSS outputs include compartment membrane voltage, spikes, local-field potentials, and current source densities, as well as visualization of the behavior of a simulated agent. An explanation of the modeling philosophy and plug-in development is also presented. Further development of KInNeSS is ongoing with the ultimate goal of creating a modular framework that will help researchers across different disciplines to effectively collaborate using a modern neural simulation platform. PMID:18695948

  20. The Symbiotic System SS73 17 seen with Suzaku

    NASA Technical Reports Server (NTRS)

    Smith, Randall K.; Mushotzky, Richard; Kallman, Tim; Tueller, Jack; Mukai, Koji; Markwardt, Craig

    2007-01-01

    We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with NH > loz3 emp2, equivalent to Av > 26, although the source has B magnitude 11.3 and is also bright in UV. The source also shows strong, narrow iron lines including fluorescent Fe K as well as Fe xxv and Fe XXVI. The X-ray spectrum can be fit with a thermal model including an absorption component that partially covers the source. Most of the equivalent width of the iron fluorescent line in this model can be explained as a combination of reprocessing in a dense absorber plus reflection off a white dwarf surface, but it is likely that the continuum is partially seen in reflection as well. Unlike other symbiotic systems that show hard X-ray emission (CH Cyg, RT Cru, T CrB, GX1+4), SS73 17 is not known to have shown nova-like optical variability, X-ray flashes, or pulsations, and has always shown faint soft X-ray emission. As a result, although it is likely a white dwarf, the nature of the compact object in SS73 17 is still uncertain. SS73 17 is probably an extreme example of the recently discovered and relatively small class of hard X-ray emitting symbiotic systems.

  1. NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA Project Title:  NARSTO ... TEOM Fluorescence Spectroscopy Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 CAMS Guide Houston Project Plan  (PDF) ...

  2. NARSTO EPA SS HOUSTON TEXAQS2000 PM SIZE MASS

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 PM SIZE MASS Project Title:  NARSTO ... Aerosol Collector Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 PM Size Guide Houston Project Plan  (PDF) ...

  3. NARSTO EPA SS HOUSTON TEXAQS2000 PM FTIR

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 PM FTIR Project Title:  NARSTO ... Transform Infrared Spectrometer) Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston TexAQS2000 PM Guide Houston Project Plan  (PDF) ...

  4. NARSTO EPA SS HOUSTON NO3 SO4 C DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON NO3 SO4 C DATA Project Title:  NARSTO ... IR Carbon Dioxide Analyzer Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston NO3 SO4 Guide Houston Project Plan  (PDF) ...

  5. NARSTO EPA SS HOUSTON NH3 HNO3 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON NH3 HNO3 DATA Project Title:  NARSTO ... Ion Chromatograph Location:  Houston, Texas Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Houston HN3 HNO3 Guide Houston Project Plan  (PDF) ...

  6. Outburst from SS 433 observed with BOOTES-2/COLORES

    NASA Astrophysics Data System (ADS)

    Caballero-Garcia, M. D.; Castro-Tirado, A.; Jelinek, M.; et al.

    2014-08-01

    In light of the recent extreme outburst of SS 433 (ATELs #6347, #6355) and follow-up by SWIFT (ATEL #6364) the 0.6m TELMA robotic telescope at the BOOTES-2 (+COLORES) astronomical station in Malaga (Spain), obtained optical 4000-9000 A spectra starting at 2014-08-01 and ending at 2014-08-07.

  7. Elimination of intergranular corrosion susceptibility of cold-worked and sensitized AlSl 316 SS by laser surface melting

    NASA Astrophysics Data System (ADS)

    Parvathavarthini, N.; Subbarao, R. V.; Dayal, R. K.; Khatak, H. S.; Kumar, Sanjay

    2001-02-01

    Susceptibility to intergranular corrosion (IGC) and intergranular stress corrosion cracking (IGSCC) due to sensitization is one of the major problems associated with austenitic stainless steels. Thermal exposures encountered during fabrication (welding, hot working, etc.) and elevated temperature service may lead to sensitization of components of austenitic stainless steels. Laser surface melting (LSM) is an in-situ method to increase the life of a sensitized component by modifying the surface microstructure without affecting the bulk properties. In this paper, the results obtained in the attempt to improve IGC resistance of coldworked and sensitized 316 SS by LSM are presented. Type 316 SS specimens cold worked to various degrees ranging from 5 to 25% reduction in thickness and sensitized to different degrees by exposing at 898 K for different durations were laser surface melted using continuous wave (cw) CO2 laser. ASTM standard A262 practice A, optical metallography, and ASTM standard G108 were used to characterize the specimens before and after LSM. Influence of prior deformation on the desensitization behavior was evaluated for the laser melting conditions adopted during the investigation. Complete dissolution of M23C6 due to laser melting and suppression of re-precipitation due to rapid quenching result in a desensitized homogenous microstructure, which is immune to IGC. Under identical laser melting conditions, the extent of desensitization decreases with an increase in the degree of cold work, and hence, higher power levels and an extended interaction time must be adopted to homogenize the sensitized microstructure with prior cold work.

  8. J-R Curve Determination for Disk-shaped Compact Specimens Based on the Normalization Method and Direct Current Potential Drop Technique

    SciTech Connect

    Chen, Xiang; Nanstad, Randy K; Sokolov, Mikhail A

    2014-01-01

    Material ductile fracture toughness can be described by J-integral versus crack extension relationship (J-R curve). As a conventional J-R curve measurement method, unloading compliance (UC) becomes impractical in elevated temperature testing due to relaxation of the material and a friction induced back-up shape of the J-R curve. In addition, the UC method may underpredict the crack extension for standard disk-shaped compact (DC(T)) specimens. In order to address these issues, the normalization method and direct current potential drop (DCPD) technique were applied for determining J-R curves at 24 C and 500 C for 0.18T DC(T) specimens made from type 316L stainless steel. For comparison purchase, the UC method was also applied in 24 C tests. The normalization method was able to yield valid J-R curves in all tests. The J-R curves from the DCPD technique need adjustment to account for the potential drop induced by plastic deformation, crack blunting, etc. and after applying a newly-developed DCPD adjustment procedure, the post-adjusted DCPD J-R curves essentially matched J-R curves from the normalization method. In contrast, the UC method underpredicted the crack extension in all tests resulting in substantial deviation in the derived J-R curves manifested by high Jq values than the normalization or DCPD method. Only for tests where the UC method underpredicted the crack extension by a very small value, J-R curves determined by the UC method were similar to those determined by the normalization or DCPD method.

  9. 36 CFR 1002.5 - Research specimens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Research specimens. 1002.5... RECREATION § 1002.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in... representative of a reputable scientific or educational institution or a State or Federal agency for the...

  10. 36 CFR 1002.5 - Research specimens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Research specimens. 1002.5... RECREATION § 1002.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in... representative of a reputable scientific or educational institution or a State or Federal agency for the...

  11. 36 CFR 1002.5 - Research specimens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Research specimens. 1002.5... RECREATION § 1002.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in... representative of a reputable scientific or educational institution or a State or Federal agency for the...

  12. 36 CFR 2.5 - Research specimens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Research specimens. 2.5 Section 2.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in accordance with...

  13. 10 CFR 26.135 - Split specimens.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... shall store Bottles A and B of the specimen in a secure manner until the facility has finished testing. If the initial validity and drug test results are negative and the specimen in Bottle A will not be forwarded to the HHS-certified laboratory, the licensee testing facility may discard both Bottle A...

  14. 10 CFR 26.135 - Split specimens.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... shall store Bottles A and B of the specimen in a secure manner until the facility has finished testing. If the initial validity and drug test results are negative and the specimen in Bottle A will not be forwarded to the HHS-certified laboratory, the licensee testing facility may discard both Bottle A...

  15. Machining technique prevents undercutting in tensile specimens

    NASA Technical Reports Server (NTRS)

    Moscater, R. E.; Royster, D. M.

    1968-01-01

    Machining technique prevents undercutting at the test section in tensile specimens when machining the four corners of the reduced section. Made with a gradual taper in the test section, the width of the center of the tensile specimen is less than the width at the four corners of the reduced section.

  16. 37 CFR 2.56 - Specimens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... advertising of the services in commerce. (b)(1) A trademark specimen is a label, tag, or container for the... goods, or in the sale or advertising of the services, is acceptable. However, a photocopy of the drawing... specimen that meets the requirements of the rule (i.e., is flat and no larger than 81/2 inches (21.6...

  17. 37 CFR 1.166 - Specimens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions Plant Patents § 1.166 Specimens. The applicant may be required to furnish specimens of the plant, or its flower or fruit, in a quantity and at a time in its stage of growth as may be designated, for study and inspection....

  18. 37 CFR 1.166 - Specimens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions Plant Patents § 1.166 Specimens. The applicant may be required to furnish specimens of the plant, or its flower or fruit, in a quantity and at a time in its stage of growth as may be designated, for study and inspection....

  19. 37 CFR 1.166 - Specimens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Specimens. 1.166 Section 1.166 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES National Processing Provisions Plant Patents § 1.166 Specimens. The applicant may be required to...

  20. Making Ceramic Reference Specimens Containing Seeded Voids

    NASA Technical Reports Server (NTRS)

    Baaklini, George Y.; Klima, Stanley J.; Roth, Don J.

    1994-01-01

    Internal and surface voids of known sizes incorporated into silicon carbide and silicon nitride ceramic reference specimens at prescribed locations. Specimens used to demonstrate sensitivity and resolution in nondestructive examination techniques like scanning laser acoustic microscopy and x-radiography, and to assist in establishing proper examination procedures.

  1. 36 CFR 1002.5 - Research specimens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Research specimens. 1002.5... RECREATION § 1002.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in... of research, baseline inventories, monitoring, impact analysis, group study, or museum display...

  2. 36 CFR 1002.5 - Research specimens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Research specimens. 1002.5... RECREATION § 1002.5 Research specimens. (a) Taking plants, fish, wildlife, rocks or minerals except in... of research, baseline inventories, monitoring, impact analysis, group study, or museum display...

  3. Layered Plating Specimens For Mechanical Tests

    NASA Technical Reports Server (NTRS)

    Thompson, Linda B.; Flowers, Cecil E.

    1991-01-01

    Layered specimens readily made in standard sizes for tensile and other tests of mechanical properties. Standard specimen of metal ordinarily difficult to plate to standard grip thickness or diameter made by augmentation with easier-to-plate material followed by machining to standard size and shape.

  4. Experimental atomic scale investigation of irradiation effects in CW 316SS and UFG-CW 316SS

    NASA Astrophysics Data System (ADS)

    Pareige, P.; Etienne, A.; Radiguet, B.

    2009-06-01

    Materials of the core internals of pressurized water reactor (austenitic stainless steels) are subject to neutron irradiation. To understand the ageing mechanisms associated with irradiation and propose life predictions of components or develop new materials, irradiation damage needs to be experimentally investigated. Atomic scale investigation of a neutron-irradiated CW316 SS with the laser pulsed atom probe gives a detailed description of the solute segregation in the austenitic grains. In order to understand the mechanism of solute segregation detected in the neutron-irradiated materials, ion irradiations were performed. These latest irradiations were realized on a CW 316SS as well as on a nanostructured CW 316SS. The study of irradiation effects in a nanograin material allows first, to easily analyse grain boundary segregation and second, to test the behaviour under irradiation of a new nanostructured material. The three aspects of this atomic scale investigation (neutron irradiation effect, model ion irradiation, new nanostructured CW 316 SS) are tackled in this paper.

  5. Plastinated Knee Specimens: A Novel Educational Tool

    PubMed Central

    Neha; Lalwani, Sanjeev; Dhingra, Renu

    2013-01-01

    Introduction: During the routine dissection of knee joints in an anatomy dissection hall, it was observed that the specimens had deteriorated overtime, due to their repeated handling and the use of high concentrations of formalin for their fixation. In order to stop their further deterioration, we decided to plastinate these specimens. Thus, the present study was undertaken to prepare plastinated knee specimens from old embalmed cadavers and to compare them with freshly fixed, plastinated specimens. Objectives: 1. To plastinate old embalmed and fresh formalin fixed knee regions. 2. To demonstrate the extra and the intracapsular structures around both the plastinated knee regions. 3. To compare their morphological features in terms of their colours, dilatation and flexibility. Methods: A total of 15 knee joint specimens from among fresh formalin (5-8%) fixed (group I) and old embalmed bodies (group II) were collected, washed and plastinated by using the standard S-10 silicon technique and they were compared for their colours, dilatation and flexibility. Results: All the plastinated specimens showed an accurate reproduction of the tissue details that were comparable to those of the natural unfixed specimens. A comparison among the two groups showed a significant difference in terms of the colour, dilatation and the flexibility of the specimens. The plastinated knee joint specimens from group I were of good quality, with negligible shrinkage, more flexibility and well preserved morphologies. Conclusion: Plastinated knee specimens can serve as an excellent educational tool for the undergraduate and postgraduate students of anatomy, radiology and orthopaedics, as they are dry, odourless and nontoxic, with a good structural preservation and a higher instructional value. The fresh knee regions, when they were plastinated, were aesthetically superior in terms of their colours, dilatation and flexibility, thus making them ideal for teaching and hands-on experiences. PMID

  6. Imaging Transition Zone Thickness Beneath South America from SS Precursors

    NASA Astrophysics Data System (ADS)

    Schmerr, N.; Garnero, E.

    2006-12-01

    We image detailed upper mantle discontinuity structure beneath a number of geologically active regions, including the South American subduction zone, the Scotia plate subduction zone, and several volcanic hotspots (e.g., the Galapagos Islands), in a region ~10,000 km by 10,000 km wide, spanning 70° S to 20° N and 20° W to 110° W. Precursors to the seismic phase SS are analyzed, which form as a result of underside reflections off seismic discontinuities beneath the midpoint of the SS path and are highly sensitive to discontinuity depth and sharpness. Our SS dataset consists of over 15,000 high-quality transverse component broadband displacement seismograms collected from the Incorporated Research Institutions for Seismology (IRIS), the Canadian National Seismic Network (CNSN), as well as data from EarthScope seismic stations, and from the Canadian Northwest Experiment (CANOE) temporary broadband array deployment. This dataset densely samples several regions in our study area and significantly improves the sampling for this area compared to previous precursor studies. Data with common central SS bouncepoints are stacked to enhance precursory phases. Solution discontinuity structure depends on a number of factors, including dominant seismic period, crustal correction, signal-to-noise ratio threshold, and tomography model used for mantle heterogeneity correction. We exclude precursor data predicted to interfere with other seismic phases, such as topside reflections (e.g., s670sS), which have been demonstrated to contaminate final stacks. Solution transition zone thickness is at least 20 km thicker than global average estimates of 242 km along the northwestern portion of the South American subduction complex (Peru, Ecuador, and Columbia); this thickening extends 1000-1500 km to the east beneath the continent, but does not appear to continue south of -20° latitude along the convergent margin. A minimum of 10 km of thickening is imaged to the west of the Scotia

  7. Optimal design of biaxial tensile cruciform specimens

    NASA Astrophysics Data System (ADS)

    Demmerle, S.; Boehler, J. P.

    1993-01-01

    F OR EXPERIMENTAL investigations concerning the mechanical behaviour under biaxial stress states of rolled sheet metals, mostly cruciform flat specimens are used. By means of empirical methods, different specimen geometries have been proposed in the literature. In order to evaluate the suitability of a specimen design, a mathematically well defined criterion is developed, based on the standard deviations of the values of the stresses in the test section. Applied to the finite element method, the criterion is employed to realize the shape optimization of biaxial cruciform specimens for isotropic elastic materials. Furthermore, the performance of the obtained optimized specimen design is investigated in the case of off-axes tests on anisotropic materials. Therefore, for the first time, an original testing device, consisting of hinged fixtures with knife edges at each arm of the specimen, is applied to the biaxial test. The obtained results indicate the decisive superiority of the optimized specimens for the proper performance on isotropic materials, as well as the paramount importance of the proposed off-axes testing technique for biaxial tests on anisotropic materials.

  8. Fluence dependence of deuterium retention in oxidized SS-316

    NASA Astrophysics Data System (ADS)

    Oya, Yasuhisa; Suzuki, Sachiko; Matsuyama, Masao; Hayashi, Takumi; Yamanishi, Toshihiko; Asakura, Yamato; Okuno, Kenji

    2011-10-01

    The ion fluence dependence of deuterium retention in SS-316 during oxidation at a temperature of 673 K was studied to evaluate the dynamics of deuterium retention in the oxide layer of SS-316. The correlation between the chemical state of stainless steel and deuterium retention was evaluated using XPS and TDS. It was found that the major deuterium desorption temperatures were located at around 660 K and 935 K, which correspond to the desorption of deuterium trapped as hydroxide. The deuterium retention increased with increasing deuterium ion fluence, since the deuterium retention as hydroxide increased significantly. However, retention saturated at an ion fluence of ˜2.5 × 10 21 D + m -2. The XPS result showed that FeOOD was formed on the surface, although pure Fe also remained in the oxide layer. These facts indicate the nature of the oxide layer have a key role in deuterium trapping behavior.

  9. Validation of Robotic Surgery Simulator (RoSS).

    PubMed

    Kesavadas, Thenkurussi; Stegemann, Andrew; Sathyaseelan, Gughan; Chowriappa, Ashirwad; Srimathveeravalli, Govindarajan; Seixas-Mikelus, Stéfanie; Chandrasekhar, Rameella; Wilding, Gregory; Guru, Khurshid

    2011-01-01

    Recent growth of daVinci Robotic Surgical System as a minimally invasive surgery tool has led to a call for better training of future surgeons. In this paper, a new virtual reality simulator, called RoSS is presented. Initial results from two studies - face and content validity, are very encouraging. 90% of the cohort of expert robotic surgeons felt that the simulator was excellent or somewhat close to the touch and feel of the daVinci console. Content validity of the simulator received 90% approval in some cases. These studies demonstrate that RoSS has the potential of becoming an important training tool for the daVinci surgical robot. PMID:21335803

  10. Nuclear processes in the jets of SS 433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS 433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg-asterisk and (16)O-asterisk in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS 433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  11. Nuclear processes in the jets of SS433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg* and (16)O* in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  12. Hollow conical jet models for SS 433 - A paradigm lost?

    NASA Technical Reports Server (NTRS)

    Kochanek, Christopher S.; Hawley, John F.

    1990-01-01

    A precessing jet such as that in SS 433 may be approximated as an axisymmetric flow, if the precession time is short by comparison to the propagation time. A series of simulations has been conducted for precessing jets using an axisymmetric finite-difference hydrodynamics code. Examinations are made of hollow cylindrical jets, which lack the complication of a growing interior volume, and conical jets, which model the behavior of a precessing jet propagating on the surface of its precession cone.

  13. Revisiting the HST Fine Guidance Sensor Parallax of SS Cygni

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.; McArthur, Barbara

    2016-01-01

    Recently, our results for the HST FGS parallax of SS Cyg (Harrison et al. 2000) have been called into question due to a recent radio parallax for this object (Miller-Jones et al. 2013). We have re-analyzed the data for our FGS program on SS Cyg and derive a revised parallax of 7.3 +/- 0.2 mas (137 pc). This parallax is 17% larger than that originally published. We discuss the new analysis effort, and the reasons for the change in our result. We believe we have identified why the radio parallax (8.77 mas) disagrees with the FGS results: We find that if we allow for a roll of two degrees in the HST coordinate system, we obtain the discrepant VLBA radio parallax. It is impossible, however, for the error in the roll of HST to be more than a few tenths of a degree, or else the FGS would not lock-on to the program targets. This roll leads to the large, and erroneous VLBA parallax for SS Cyg. We note that the radio parallax for the black hole system V404 Cyg (Miller-Jones et al. 2009) is also much larger than the spectroscopic parallax of its secondary star. In addition, we closely examine the attempt by Nelan & Bond (2013) to reconcile the FGS data set with the radio result. We identify what we believe to be significant issues with their analysis. Finally, we present a quantitative abundance analysis for SS Cyg, RU Peg, and GK Per derived from moderate resolution K-band spectroscopy. We find severe carbon deficiencies (10 to 20% of the solar value) in the secondary stars of all three objects. We describe the Python program "kmoog" which generates synthetic spectra, and autonomously compares them to observational data.

  14. Computer-aided planning of SS/TDMA network operation

    NASA Astrophysics Data System (ADS)

    Mizuike, Takeshi; Nguyen, Lan N.; Ito, Yasuhiko; Maeda, Eijiro

    1991-01-01

    A computer-aided approach to the planning of SS/TDMA network operation is proposed. SS/TDMA is a sophisticated satellite communication network based on an onboard switch matrix, whose operation planning is formulated as a large-scale scheduling problem. An overall planning and scheduling model is presented to deal with practical SS/TDMA systems, such as a two-frequency channel network and nondisjoint beam coverage. For systematic planning suitable for a computer-aided approach, the entire scheduling process is divided into several steps, for each of which an efficient mathematical model is proposed. A linear programming model is used for distribution of traffic on a beam-to-beam basis and the generated switching sequence is further refined by a model using the traveling salesman problem. Burst scheduling is carried out by the Bin packing algorithm and scheduling models for practical networks allowing transponder hopping and multidestination bursts. An algorithm called enhanced rescheduling is presented to further improve the scheduling capability of the existing methods. The performance of the proposed methods is demonstrated by simulation results.

  15. THE Be STAR SPECTRA (BeSS) DATABASE

    SciTech Connect

    Neiner, C.; De Batz, B.; Cochard, F.; Floquet, M.; Mekkas, A.; Desnoux, V.

    2011-11-15

    Be stars vary on many timescales, from hours to decades. A long time base of observations to analyze certain phenomena in these stars is therefore necessary. Collecting all existing and future Be star spectra into one database has thus emerged as an important tool for the Be star community. Moreover, for statistical studies, it is useful to have centralized information on all known Be stars via an up-to-date catalog. These two goals are what the Be Star Spectra (BeSS, http://basebe.obspm.fr) database proposes to achieve. The database contains an as-complete-as-possible catalog of known Be stars with stellar parameters, as well as spectra of Be stars from all origins (any wavelength, any epoch, any resolution, etc.). It currently contains over 54,000 spectra of more than 600 different Be stars among the {approx}2000 Be stars in the catalog. A user can access and query this database to retrieve information on Be stars or spectra. Registered members can also upload spectra to enrich the database. Spectra obtained by professional as well as amateur astronomers are individually validated in terms of format and science before being included in BeSS. In this paper, we present the database itself as well as examples of the use of BeSS data in terms of statistics and the study of individual stars.

  16. LoCuSS: Testing hydrostatic equilibrium in galaxy clusters

    NASA Astrophysics Data System (ADS)

    Smith, G. P.; Mazzotta, P.; Okabe, N.; Ziparo, F.; Mulroy, S. L.; Babul, A.; Finoguenov, A.; McCarthy, I. G.; Lieu, M.; Bahé, Y. M.; Bourdin, H.; Evrard, A. E.; Futamase, T.; Haines, C. P.; Jauzac, M.; Marrone, D. P.; Martino, R.; May, P. E.; Taylor, J. E.; Umetsu, K.

    2016-02-01

    We test the assumption of hydrostatic equilibrium in an X-ray luminosity selected sample of 50 galaxy clusters at 0.15 < z < 0.3 from the Local Cluster Substructure Survey (LoCuSS). Our weak-lensing measurements of M500 control systematic biases to sub-4 per cent, and our hydrostatic measurements of the same achieve excellent agreement between XMM-Newton and Chandra. The mean ratio of X-ray to lensing mass for these 50 clusters is β_X= 0.95± 0.05, and for the 44 clusters also detected by Planck, the mean ratio of Planck mass estimate to LoCuSS lensing mass is β_P= 0.95± 0.04. Based on a careful like-for-like analysis, we find that LoCuSS, the Canadian Cluster Comparison Project, and Weighing the Giants agree on β_P ≃ 0.9-0.95 at 0.15 < z < 0.3. This small level of hydrostatic bias disagrees at ˜5σ with the level required to reconcile Planck cosmology results from the cosmic microwave background and galaxy cluster counts.

  17. The astrophysical torus. 2: Light curves of SS 433

    NASA Astrophysics Data System (ADS)

    Sanbuichi, Kiyotaka; Fukue, Jun

    1993-10-01

    Using the mass function obtained by D'Odorico et al. (1991), we recalculate the theoretical light curves of SS 433 in the primary eclipse and confront them with observations. We assume that in SS 433 there exists a geometrically thick torus around a compact object, and that the primary eclipse is an eclipse of the torus by a companion of an early-type star. The main parameters are the shape of the tori, the size of the tori, and the binary mass ratio. We obtain light curves for several combinations of parameters. The light curves for sufficiently thick tori are deep at the mid-eclipse and preferable, while those for geometrically thin tori are shallow. The duration of eclipse for a large torus is long and beneficial, while that for a small torus is short. Finally, Delta m at mid-eclipse for a thick torus around a neutron star becomes approximately 0.6 and suitable, whereas for thick tori around a black hole it is approximately 0.3. Hence, under the new mass function, geometrically thick and wide tori around a neutron star can well reproduce the observed light curves of SS 433.

  18. Specimen for high-temperature tensile tests

    NASA Technical Reports Server (NTRS)

    Coulbert, C. D.

    1972-01-01

    Split nut with internal taper to hold specially formed specimen composed of filaments of refractory material provides means for holding at high temperature and under tension so that performance evaluations may be made.

  19. 37 CFR 2.56 - Specimens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... specimen”), the Office will create a digital facsimile of the specimen that meets the requirements of the...-bulky alternatives, the Office may accept an audio or video cassette tape recording, CD-ROM, or...

  20. 37 CFR 2.56 - Specimens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... exceeding these size requirements (a “bulky specimen”), the Office will create a digital facsimile of the... bulky specimen. (3) In the absence of non-bulky alternatives, the Office may accept an audio or...

  1. A Live Specimen Cell for the Microscope.

    ERIC Educational Resources Information Center

    McNeil, D. W.

    1991-01-01

    Provides background and instructions for the assembly of a microaquarium, or specimen cell, in which the dynamic world of living microorganisms can be viewed through a microscope overextended periods of time utilizing the simplest of materials in the process. (JJK)

  2. Impact of specimen adequacy on the assessment of renal allograft biopsy specimens

    PubMed Central

    Cimen, S.; Geldenhuys, L.; Guler, S.; Imamoglu, A.; Molinari, M.

    2016-01-01

    The Banff classification was introduced to achieve uniformity in the assessment of renal allograft biopsies. The primary aim of this study was to evaluate the impact of specimen adequacy on the Banff classification. All renal allograft biopsies obtained between July 2010 and June 2012 for suspicion of acute rejection were included. Pre-biopsy clinical data on suspected diagnosis and time from renal transplantation were provided to a nephropathologist who was blinded to the original pathological report. Second pathological readings were compared with the original to assess agreement stratified by specimen adequacy. Cohen's kappa test and Fisher's exact test were used for statistical analyses. Forty-nine specimens were reviewed. Among these specimens, 81.6% were classified as adequate, 6.12% as minimal, and 12.24% as unsatisfactory. The agreement analysis among the first and second readings revealed a kappa value of 0.97. Full agreement between readings was found in 75% of the adequate specimens, 66.7 and 50% for minimal and unsatisfactory specimens, respectively. There was no agreement between readings in 5% of the adequate specimens and 16.7% of the unsatisfactory specimens. For the entire sample full agreement was found in 71.4%, partial agreement in 20.4% and no agreement in 8.2% of the specimens. Statistical analysis using Fisher's exact test yielded a P value above 0.25 showing that - probably due to small sample size - the results were not statistically significant. Specimen adequacy may be a determinant of a diagnostic agreement in renal allograft specimen assessment. While additional studies including larger case numbers are required to further delineate the impact of specimen adequacy on the reliability of histopathological assessments, specimen quality must be considered during clinical decision making while dealing with biopsy reports based on minimal or unsatisfactory specimens. PMID:27119314

  3. Mode 2 fatigue crack growth specimen development

    NASA Technical Reports Server (NTRS)

    Buzzard, R. J.; Gross, B.; Srawley, J. E.

    1983-01-01

    A Mode II test specimen was developed which has potential application in understanding phemonena associated with mixed mode fatigue failures in high performance aircraft engine bearing races. The attributes of the specimen are: it contains one single ended notch, which simplifiers data gathering and reduction; the fatigue crack grous in-line with the direction of load application; a single axis test machine is sufficient to perform testing; and the Mode I component is vanishingly small.

  4. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.

    2013-11-01

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K {sub s}) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10{sup 8-9} cm{sup –3}), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in

  5. STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS

    SciTech Connect

    Lam, P; Philip Zapp, P; Jonathan Duffey, J; Kerry Dunn, K

    2009-05-01

    Laboratory tests were conducted to investigate the stress corrosion cracking (SCC) of 304L stainless steel used to construct the containment vessels for the storage of plutonium-bearing materials. The tear drop corrosion specimens each with an autogenous weld in the center were placed in contact with moist plutonium oxide and chloride salt mixtures. Cracking was found in two of the specimens in the heat affected zone (HAZ) at the apex area. Finite element analysis was performed to simulate the specimen fabrication for determining the internal stress which caused SCC to occur. It was found that the tensile stress at the crack initiation site was about 30% lower than the highest stress which had been shifted to the shoulders of the specimen due to the specimen fabrication process. This finding appears to indicate that the SCC initiation took place in favor of the possibly weaker weld/base metal interface at a sufficiently high level of background stress. The base material, even subject to a higher tensile stress, was not cracked. The relieving of tensile stress due to SCC initiation and growth in the HAZ and the weld might have foreclosed the potential for cracking at the specimen shoulders where higher stress was found.

  6. Nanocomposite coatings on biomedical grade stainless steel for improved corrosion resistance and biocompatibility.

    PubMed

    Nagarajan, Srinivasan; Mohana, Marimuthu; Sudhagar, Pitchaimuthu; Raman, Vedarajan; Nishimura, Toshiyasu; Kim, Sanghyo; Kang, Yong Soo; Rajendran, Nallaiyan

    2012-10-24

    The 316 L stainless steel is one of the most commonly available commercial implant materials with a few limitations in its ease of biocompatibility and long-standing performance. Hence, porous TiO(2)/ZrO(2) nanocomposite coated over 316 L stainless steels was studied for their enhanced performance in terms of its biocompatibility and corrosion resistance, following a sol-gel process via dip-coating technique. The surface composition and porosity texture was studied to be uniform on the substrate. Biocompatibility studies on the TiO(2)/ZrO(2) nanocomposite coatings were investigated by placing the coated substrate in a simulated body fluid (SBF). The immersion procedure resulted in the complete coverage of the TiO(2)/ZrO(2) nanocomposite (coated on the surface of 316 L stainless steel) with the growth of a one-dimensional (1D) rod-like carbonate-containing apatite. The TiO(2)/ZrO(2) nanocomposite coated specimens showed a higher corrosion resistance in the SBF solution with an enhanced biocompatibility, surpassing the performance of the pure oxide coatings. The cell viability of TiO(2)/ZrO(2) nanocomposite coated implant surface was examined under human dermal fibroblasts culture, and it was observed that the composite coating enhances the proliferation through effective cellular attachment compared to pristine 316 L SS surface. PMID:22967070

  7. DPA damage analysis for 14-MeV neutrons on PFC materials

    NASA Astrophysics Data System (ADS)

    Kim, Dong-woo; Lee, Bo-young; Ko, Seung-kook; Kim, Hee-soo; Noh, Seung-jung

    2015-06-01

    The dpa (displacement per atom) damage for 14-MeV neutron in a pfc materials was simulated using MCNPX/SPECTER code. The dpa values in the main components of the structural material SS316L, Fe, Cr and Ni, were calculated to analyze the effect of nuclear damage. According to the neutron wall load for ITER design base, a neutron flux of 3.5 × 1013 neutrons/cm2·sec was applied. The simulated dpa values were found to be as 3.0 dpa/fpy for Fe, 2.9 dpa/fpy for Cr and 3.1 dpa/fpy for Ni. For practical experiments, the simulated dpa values due to the irradiation damage of 17-MeV protons were found to be as 0.67 dpa at the peak and 0.05 at the surface for SS316L using by SRIM code at the same fluence. For the 17-MeV proton irradiation, the Bragg peak appears at a 0.64-mm depth. Also, SS316L specimens irradiated by a 17-MeV proton beam with a fluence of 1016 protons/cm2 were analyzed by using transmission electron microscopy.

  8. Synthesis and corrosion protection properties of poly(o-phenylenediamine) nanofibers

    PubMed Central

    Muthirulan, P.; Kannan, N.; Meenakshisundaram, M.

    2012-01-01

    The present study shows a novel method for the synthesis of uniformly-shaped poly(othophenylediamine) (PoPD) nanofibers by chemical oxidative polymerization method for application towards smart corrosion resistance coatings. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) studies confirm morphology of PoPD with three dimensional (3D) networked dendritic superstructures having average diameter of 50–70 nm and several hundred meters of length. UV–vis and FTIR spectral results shows the formation of PoPD nanofibers containing phenazine ring ladder-structure with benzenoid and quinoid imine units. Thermogravimetric analyses (TGA) of PoPD nanofibers possess good thermal stability. The anti-corrosion behavior of PoPD nanofibers on 316L SS was investigated in 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements. The PoPD coated 316L SS exhibits higher corrosion potential when compared to uncoated specimen. EIS studies, clearly ascertain that PoPD nanofiber coatings exhibits excellent potential barrier to protect the 316L SS against corrosion in 3.5% NaCl. PMID:25685444

  9. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  10. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  11. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  12. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  13. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  14. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  15. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  16. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  17. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  18. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  19. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  20. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  1. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  2. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  3. Closeout of JOYO-1 Specimen Fabrication Efforts

    SciTech Connect

    ME Petrichek; JL Bump; RF Luther

    2005-10-31

    Fabrication was well under way for the JOYO biaxial creep and tensile specimens when the NR Space program was canceled. Tubes of FS-85, ASTAR-811C, and T-111 for biaxial creep specimens had been drawn at True Tube (Paso Robles, CA), while tubes of Mo-47.5 Re were being drawn at Rhenium Alloys (Cleveland, OH). The Mo-47.5 Re tubes are now approximately 95% complete. Their fabrication and the quantities produced will be documented at a later date. End cap material for FS-85, ASTAR-811C, and T-111 had been swaged at Pittsburgh Materials Technology, Inc. (PMTI) (Large, PA) and machined at Vangura (Clairton, PA). Cutting of tubes, pickling, annealing, and laser engraving were in process at PMTI. Several biaxial creep specimen sets of FS-85, ASTAR-811C, and T-111 had already been sent to Pacific Northwest National Laboratory (PNNL) for weld development. In addition, tensile specimens of FS-85, ASTAR-811C, T-111, and Mo-47.5 Re had been machined at Kin-Tech (North Huntington, PA). Actual machining of the other specimen types had not been initiated. Flowcharts 1-3 detail the major processing steps each piece of material has experienced. A more detailed description of processing will be provided in a separate document [B-MT(SRME)-51]. Table 1 lists the in-process materials and finished specimens. Also included are current metallurgical condition of these materials and specimens. The available chemical analyses for these alloys at various points in the process are provided in Table 2.

  4. Unusual Histopathological Findings in Childhood Appendectomy Specimens.

    PubMed

    Buyukbese Sarsu, Sevgi; Ucak, Ramazan; Buyukbese, Mehmet Akif; Karakus, Suleyman Cuneyt; Deniz, Hale

    2015-12-01

    The purpose of this study was to find the unusual findings in the childhood appendectomy specimens and their incidence. The clinicopathological data of 1,306 patients whose ages ranged from 3 to 16 were retrospectively collected. Histopathological findings in appendectomy specimens taken from patients who had a prediagnosis of appendicitis were obtained. Incidental appendectomies were not included in the research. Unusual findings were reevaluated in the histopathological assessment of appendectomy specimens. The number of patients whose pathological findings are considered unusual is 25 (1.91 %). Nine of the patients were girls and 16 of them were boys. Their ages ranged from 6 to 15. Pathological results revealed that there were 16 (1.22 %) cases of parasitosis, 3 (0.23 %) cases of granulomatosis, 3 (0.23 %) cases of eosinophilic appendicitis, 2 (0.15 %) cases of carcinoid tumors, and 1 (0.08 %) case of appendiceal non-Hodgkin's lymphoma. All patients underwent a standard appendectomy. Uncommon histopathological findings in childhood appendectomy specimens are more common than those in adulthood. This kind of certain unexpected lesions of the appendix may require advanced diagnostics, careful clinical care, follow-up for years, and a multidisciplinary approach. Therefore, histopathological examinations of appendectomy specimens must be performed routinely. PMID:26730070

  5. Histopathologic findings in breast reduction specimens.

    PubMed

    Kececi, Yavuz; Tasli, Funda Alkan; Yagcı, Ayse; Sır, Emin; Canpolat, Selin; Vardar, Enver

    2014-04-01

    Reduction mammaplasty is a commonly performed operation for treatment of breast hypertrophy. It allows examination of specimens from a seemingly healthy population. Although there are many publications reporting the incidence of occult breast carcinomas, only a few studies have specifically examined the incidence of other breast lesions in reduction mammaplasty specimens. The authors conducted a single-centre retrospective chart review examining the incidence of benign and precancerous lesions in breast reduction specimens. Both age and the number of tissue sections were evaluated for the association with important pathologic findings. Of the 95 patients who underwent reduction mammaplasty, eight patients (8.4%) had atypical lesions. Fourteen patients (15%) had proliferative and 54 patients (57%) had non-proliferative breast lesions. No occult invasive breast cancer was identified in the breast reduction specimens. The existence of significant pathologic findings was not associated with age (p = 0.231, student t-test). On the other hand, it was found to be associated with the number of tissue sections (p = 0.046, Mann-Whitney U-test). This study reveals that breast reduction specimens should be analyzed histologically since a considerable amount of patients have breast lesions with increased cancer risk. Therefore, this analysis would guide the management of these patients in the follow-up period. PMID:23879776

  6. Mycobacterium avium ss. paratuberculosis Zoonosis – The Hundred Year War – Beyond Crohn’s Disease

    PubMed Central

    Sechi, Leonardo A.; Dow, Coad Thomas

    2015-01-01

    The factitive role of Mycobacterium avium ss. paratuberculosis (MAP) in Crohn’s disease has been debated for more than a century. The controversy is due to the fact that Crohn’s disease is so similar to a disease of MAP-infected ruminant animals, Johne’s disease; and, though MAP can be readily detected in the infected ruminants, it is much more difficult to detect in humans. Molecular techniques that can detect MAP in pathologic Crohn’s specimens as well as dedicated specialty labs successful in culturing MAP from Crohn’s patients have provided strong argument for MAP’s role in Crohn’s disease. Perhaps more incriminating for MAP as a zoonotic agent is the increasing number of diseases with which MAP has been related: Blau syndrome, type 1 diabetes, Hashimoto thyroiditis, and multiple sclerosis. In this article, we debate about genetic susceptibility to mycobacterial infection and human exposure to MAP; moreover, it suggests that molecular mimicry between protein epitopes of MAP and human proteins is a likely bridge between infection and these autoimmune disorders. PMID:25788897

  7. PCI-SS: MISO dynamic nonlinear protein secondary structure prediction

    PubMed Central

    Green, James R; Korenberg, Michael J; Aboul-Magd, Mohammed O

    2009-01-01

    Background Since the function of a protein is largely dictated by its three dimensional configuration, determining a protein's structure is of fundamental importance to biology. Here we report on a novel approach to determining the one dimensional secondary structure of proteins (distinguishing α-helices, β-strands, and non-regular structures) from primary sequence data which makes use of Parallel Cascade Identification (PCI), a powerful technique from the field of nonlinear system identification. Results Using PSI-BLAST divergent evolutionary profiles as input data, dynamic nonlinear systems are built through a black-box approach to model the process of protein folding. Genetic algorithms (GAs) are applied in order to optimize the architectural parameters of the PCI models. The three-state prediction problem is broken down into a combination of three binary sub-problems and protein structure classifiers are built using 2 layers of PCI classifiers. Careful construction of the optimization, training, and test datasets ensures that no homology exists between any training and testing data. A detailed comparison between PCI and 9 contemporary methods is provided over a set of 125 new protein chains guaranteed to be dissimilar to all training data. Unlike other secondary structure prediction methods, here a web service is developed to provide both human- and machine-readable interfaces to PCI-based protein secondary structure prediction. This server, called PCI-SS, is available at . In addition to a dynamic PHP-generated web interface for humans, a Simple Object Access Protocol (SOAP) interface is added to permit invocation of the PCI-SS service remotely. This machine-readable interface facilitates incorporation of PCI-SS into multi-faceted systems biology analysis pipelines requiring protein secondary structure information, and greatly simplifies high-throughput analyses. XML is used to represent the input protein sequence data and also to encode the resulting

  8. EUVE photometry of SS Cygni: Dwarf nova outbursts and oscillations

    SciTech Connect

    Mauche, C.W.

    1995-05-15

    The authors present EUVE Deep Survey photometry and AAVSO optical measurements of the 1993 August and 1994 June/July outbursts of the dwarf nova SS Cygni. The EUV and optical light curves are used to illustrate the different response of the accretion disk to outbursts which begin at the inner edge and propagate outward, and those which begin at the outer edge and propagate inward. Furthermore, the authors describe the properties of the quasi-coherent 7--9 s sinusoidal oscillations in the EUV flux detected during the rise and plateau stages of these outbursts.

  9. Osler usque ad mare: the SS William Osler

    PubMed Central

    Bryan, C S; Fransiszyn, M

    1999-01-01

    William Osler's connections with the sea included a strong family history of seafaring, his own transatlantic crossings (of which there were at least 32) and the occasional use of nautical imagery in his inspirational writings. An unusual Oslerian connection with the sea emerged after his death in the form of a World War II Liberty ship. Through the SS William Osler and its sister ships, Osler was symbolically reunited with colleagues associated with the early days of the Johns Hopkins Hospital. The William Osler circumnavigated the globe in 1943 without engaging the enemy. She was then converted into an army hospital ship and renamed the USHS Wisteria. PMID:10530306

  10. ss3sim: An R Package for Fisheries Stock Assessment Simulation with Stock Synthesis

    PubMed Central

    Anderson, Sean C.; Monnahan, Cole C.; Johnson, Kelli F.; Ono, Kotaro; Valero, Juan L.

    2014-01-01

    Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, the fisheries stock assessment modeling framework Stock Synthesis (SS3) has become widely used around the world. However, there lacks a generalized and scriptable framework for SS3 simulation testing. Here, we introduce ss3sim, an R package that facilitates reproducible, flexible, and rapid end-to-end simulation testing with SS3. ss3sim requires an existing SS3 model configuration along with plain-text control files describing alternative population dynamics, fishery properties, sampling scenarios, and assessment approaches. ss3sim then generates an underlying ‘truth’ from a specified operating model, samples from that truth, modifies and runs an estimation model, and synthesizes the results. The simulations can be run in parallel, reducing runtime, and the source code is free to be modified under an open-source MIT license. ss3sim is designed to explore structural differences between the underlying truth and assumptions of an estimation model, or between multiple estimation model configurations. For example, ss3sim can be used to answer questions about model misspecification, retrospective patterns, and the relative importance of different types of fisheries data. We demonstrate the software with an example, discuss how ss3sim complements other simulation software, and outline specific research questions that ss3sim could address. PMID:24699270

  11. Surface analysis of space telescope material specimens

    NASA Technical Reports Server (NTRS)

    Fromhold, A. T.; Daneshvar, K.

    1985-01-01

    Qualitative and quantitative data on Space Telescope materials which were exposed to low Earth orbital atomic oxygen in a controlled experiment during the 41-G (STS-17) mission were obtained utilizing the experimental techniques of Rutherford backscattering (RBS), particle induced X-ray emission (PIXE), and ellipsometry (ELL). The techniques employed were chosen with a view towards appropriateness for the sample in question, after consultation with NASA scientific personnel who provided the material specimens. A group of eight samples and their controls selected by NASA scientists were measured before and after flight. Information reported herein include specimen surface characterization by ellipsometry techniques, a determination of the thickness of the evaporated metal specimens by RBS, and a determination of trace impurity species present on and within the surface by PIXE.

  12. Stress intensity factor in a tapered specimen

    NASA Technical Reports Server (NTRS)

    Xue-Hui, L.; Erdogan, F.

    1985-01-01

    The general problem of a tapered specimen containing an edge crack is formulated in terms of a system of singular integral equations. The equations are solved and the stress intensity factor is calculated for a compact and for a slender tapered specimen, the latter simulating the double cantilever beam. The results are obtained primarily for a pair of concentrated forces and for crack surface wedge forces. The stress intensity factors are also obtained for a long strip under uniform tension which contains inclined edge cracks.

  13. Acousto-microfluidics for screening of ssDNA aptamer

    PubMed Central

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8th round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  14. Acousto-microfluidics for screening of ssDNA aptamer.

    PubMed

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8(th) round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  15. XTE Proposal #20102--"SS 433's High Energy Spectrum"

    NASA Technical Reports Server (NTRS)

    Band, David L.; Blanco, P.; Rothschild, R.; Kawai, N.; Kotani, T.; Oka, T.; Wagner, R. M.; Hjellming, R.; Rupen, M.; Brinkmann, W.

    1999-01-01

    We observed the jet-producing compact binary system SS 433 with RXTE during three multiwavelength campaigns, the first in conjunction with ASCA observations, the second simultaneous with a VLA-VLBA-MERLIN campaign, and the third associated with a Nobeyama millimeter-band campaign. All these campaigns included optical observations. Occurring at different jet precession and binary phases, the observations also monitored the system during a radio flare. The data provide SS 433's X-ray spectrum over more than an energy decade, and track the spectral variations as the X-ray source was partially eclipsed. The continuum can be modeled as a power law with an exponential cutoff, which can be detected to approximately 50 keV. Strong line emission is evident in the 5-10 keV range which can be modeled as a broad line whose energy is precession independent and a narrow line whose energy does vary with jet precession phase; this line model is clearly an over simplification since the PCA does not have sufficient energy resolution to detect the lines ASCA observed. The eclipses are deeper at high energy and at jet precession phases when the jets are more inclined towards and away from us. A large radio flare occurred between two sets of X-ray monitoring observations; an X-ray observation at the peak of the flare found a softer spectrum with a flux approximately 1/3 that of the quiescent level.

  16. Capillary electrophoresis of small ssDNA molecules

    NASA Astrophysics Data System (ADS)

    Kopecka, Katerina; Slater, Gary W.; Drouin, Guy

    2004-03-01

    Recently, the electrophoretic separation of small ssDNA fragments (bellow 250 bases) has attracted a lot of attention because of applications related to Single Nucleotide Polymorphisms. In order to optimize these systems, we require a better understanding of DNA migration behavior in this size range. While the reptation model provides an excellent understanding of the dynamics of long DNA fragments in gel electrophoresis, the properties of small DNA fragments has not been studied extensively yet. At least three theoretical formulas have been proposed to explain the mobility of short ssDNA molecules in this regime. Specifically, the Ogston regime was introduced for small molecules having radii-of-gyration comparable to or smaller than the pore size of the sieving matrix. We introduce these three different formulas and discuss how their free parameters are related to actual physical parameters. We then test these formulas with new data obtained by capillary electrophoresis in our laboratory using poly(dimethylacrylamide) sieving matrices. Our results show that all three formulas provide decent fits, and that their fitting parameters are consistent with one another. This is the first step towards the development of a systematic approach to optimizing sequencing systems for this size range.

  17. Reversibly shielded DNA polyplexes based on bioreducible PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers mediate markedly enhanced nonviral gene transfection.

    PubMed

    Zhu, Caihong; Zheng, Meng; Meng, Fenghua; Mickler, Frauke Martina; Ruthardt, Nadia; Zhu, Xiulin; Zhong, Zhiyuan

    2012-03-12

    Reversibly shielded DNA polyplexes based on bioreducible poly(dimethylaminoethyl methacrylate)-SS-poly(ethylene glycol)-SS-poly(dimethylaminoethyl methacrylate) (PDMAEMA-SS-PEG-SS-PDMAEMA) triblock copolymers were designed, prepared and investigated for in vitro gene transfection. Two PDMAEMA-SS-PEG-SS-PDMAEMA copolymers with controlled compositions, 6.6-6-6.6 and 13-6-13 kDa, were obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization of dimethylaminoethyl methacrylate (DMAEMA) using CPADN-SS-PEG-SS-CPADN (CPADN: 4-cyanopentanoic acid dithionaphthalenoate; PEG: 6 kDa) as a macro-RAFT agent. Like their nonreducible PDMAEMA-PEG-PDMAEMA analogues, PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers could effectively condense DNA into small particles with average diameters less than 120 nm and close to neutral zeta potentials (0 ∼ +6 mV) at and above an N/P ratio of 3/1. The resulting polyplexes showed excellent colloidal stability against 150 mM NaCl, which contrasts with polyplexes of 20 kDa PDMAEMA homopolymer. In the presence of 10 mM dithiothreitol (DTT), however, polyplexes of PDMAEMA-SS-PEG-SS-PDMAEMA were rapidly deshielded and unpacked, as revealed by significant increase of positive surface charges as well as increase of particle sizes to over 1000 nm. Release of DNA in response to 10 mM DTT was further confirmed by gel retardation assays. These polyplexes, either stably or reversibly shielded, revealed a low cytotoxicity (over 80% cell viability) at and below an N/P ratio of 12/1. Notably, in vitro transfection studies showed that reversibly shielded polyplexes afforded up to 28 times higher transfection efficacy as compared to stably shielded control under otherwise the same conditions. Confocal laser scanning microscope (CLSM) studies revealed that reversibly shielded polyplexes efficiently delivered and released pDNA into the perinuclei region as well as nuclei of COS-7 cells. Hence, reduction-sensitive reversibly shielded DNA

  18. 16 CFR Figure 6 to Subpart A of... - Dummy Specimen in Specimen Holder

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Dummy Specimen in Specimen Holder 6 Figure 6 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt....

  19. 16 CFR Figure 6 to Subpart A of... - Dummy Specimen in Specimen Holder

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Dummy Specimen in Specimen Holder 6 Figure 6 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt....

  20. 16 CFR Figure 6 to Subpart A of... - Dummy Specimen in Specimen Holder

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Dummy Specimen in Specimen Holder 6 Figure 6 to Subpart A of Part 1209 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS INTERIM SAFETY STANDARD FOR CELLULOSE INSULATION The Standard Pt. 1209, Subpt....