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Sample records for a533b steels investigated

  1. Effect of neutron irradiation on the impact properties of A533B steel

    SciTech Connect

    Schubert, L.E.; Kumar, A.S.; Rosinski, S.T.; Hamilton, M.L.

    1994-10-01

    A new methodology is proposed to correlate the upper shelf energy (USE) of full size and subsize Charpy specimens of a nuclear reactor pressure vessel plate material, ASTM type A 533 Grade B (A533B) having a low USE (USE < 100 J). The methodology appears to be more satisfactory than those methodologies proposed earlier. The USE was normalized by a normalization factor involving the dimensions of the Charpy specimen, the elastic stress concentration factor, and the plastic constraint at the notch root. The normalized values of the USE were found to be invariant with specimen size. In addition, it was also found that the ratio of the USE of unirradiated to that of irradiated materials was approximately the same for full, half, and third size specimens. The ductile-to-brittle transition temperature (DBTT) increased due to irradiation at 150 C to a nominal fluence of 1.0 {times} 10{sup 19} n/cm{sup 2} (E > 1 MeV) by 78 {degree}, 83{degree}, and 70{degree}C for full, half, and third size specimens, respectively. These shifts in DBTT appeared to be independent of specimen size and notch geometry.

  2. Magnetic evaluation of irradiation hardening in A533B reactor pressure vessel steels: Magnetic hysteresis measurements and the model analysis

    NASA Astrophysics Data System (ADS)

    Kobayashi, S.; Yamamoto, T.; Klingensmith, D.; Odette, G. R.; Kikuchi, H.; Kamada, Y.

    2012-03-01

    We report results of measurements of magnetic minor hysteresis loops for neutron-irradiated A533B nuclear reactor pressure vessel steels varying alloy composition and irradiation condition. A minor-loop coefficient, which is obtained from a scaling power law between minor-loop parameters exhibits a steep decrease just after irradiation, followed by a maximum in the intermediate fluence regime for most alloys. A model analysis assuming Avrami-type growth for Cu-rich precipitates and an empirical logarithmic law for relaxation of residual stress demonstrates that an increment of the coefficient due to Cu-rich precipitates increases with Cu and Ni contents and is in proportion to a yield stress change, which is related to irradiation hardening.

  3. Analysis of the irradiation data for A302B and A533B correlation monitor materials

    SciTech Connect

    Wang, J.A.

    1996-04-01

    The results of Charpy V-notch impact tests for A302B and A533B-1 Correlation Monitor Materials (CMM) listed in the surveillance power reactor data base (PR-EDB) and material test reactor data base (TR-EDB) are analyzed. The shift of the transition temperature at 30 ft-lb (T{sub 30}) is considered as the primary measure of radiation embrittlement in this report. The hyperbolic tangent fitting model and uncertainty of the fitting parameters for Charpy impact tests are presented in this report. For the surveillance CMM data, the transition temperature shifts at 30 ft-lb ({Delta}T{sub 30}) generally follow the predictions provided by Revision 2 of Regulatory Guide 1.99 (R.G. 1.99). Difference in capsule temperatures is a likely explanation for large deviations from R.G. 1.99 predictions. Deviations from the R.G. 1.99 predictions are correlated to similar deviations for the accompanying materials in the same capsules, but large random fluctuations prevent precise quantitative determination. Significant scatter is noted in the surveillance data, some of which may be attributed to variations from one specimen set to another, or inherent in Charpy V-notch testing. The major contributions to the uncertainty of the R.G. 1.99 prediction model, and the overall data scatter are from mechanical test results, chemical analysis, irradiation environments, fluence evaluation, and inhomogeneous material properties. Thus in order to improve the prediction model, control of the above-mentioned error sources needs to be improved. In general the embrittlement behavior of both the A302B and A533B-1 plate materials is similar. There is evidence for a fluence-rate effect in the CMM data irradiated in test reactors; thus its implication on power reactor surveillance programs deserves special attention.

  4. Effect of specimen size on the impact properties of neutron irradiated A533B steel

    NASA Astrophysics Data System (ADS)

    Schubert, L. E.; Kumar, A. S.; Rosinki, Stan T.; Hamilton, Margaret L.

    1995-08-01

    A new methodology is proposed to correlate the upper shelf energy (USE) of full-size and subsize Charpy specimens of a nuclear reactor pressure vessel plate material. The methodology appears to be more satisfactory than those methodlogies proposed earlier. The USE was normalized by a normalization factor involving the dimensions of the Charpy specimen, the elastic stress concentration factor, and the plastic constraint at the notch root. The normalized values of the USE were found to be invariant with speciment size. In addition, it was also found that the ratio of the USE of unirradiated to that of irradiated materials was approximately the same for full-, half-, and third-size specimens. The ductile-to-brittle transition temperture (DBTT) increased due to irradiation at 150°C to a nominal fluence of 1.0 × 10 19 n/cm 2 ( E >MeV) by 78, 83 and 70°C for full-, half-, and third-size specimens, respectively. These shifts in DBTT appeared to be independent of specimen size and notch geometry.

  5. Segregation behavior of phosphorus in the heat-affected zone of an A533B/A182 dissimilar weld joint before and after simulated thermal aging

    NASA Astrophysics Data System (ADS)

    Zhai, Ziqing; Miyahara, Yuichi; Abe, Hiroshi; Watanabe, Yutaka

    2014-09-01

    The segregation behavior of phosphorus (P) in the heat-affected zone (HAZ) of an A533B/A182 dissimilar weld joint before and after step cooling was investigated with atom probe tomography. At grain/packet boundaries, the final P segregation level consisted of non-equilibrium segregation that occurred during cooling after welding and post-weld heat treatment (PWHT) and equilibrium segregation that occurred during step cooling. In both processes, higher P coverage was observed in the coarse-grained and intercritically reheated coarse-grained HAZ than in the fine-grained HAZ and base material. The cooling after welding and PWHT seemed to have a pronounced impact on P segregation in the subsequent aging process. In addition, P segregation also occurred at the precipitate/matrix interfaces of cementite, Mo2C and Al-Si rich precipitates. The evolution of P coverage at these two types of sites suggested increasing risks of embrittlement with an increase in aging time.

  6. Low-alloy steels for thick-walled pressure vessels. Summary report, February 1, 1980-January 31, 1982

    SciTech Connect

    Todd, J.A.; Chung, D.W.; Parker, E.R.

    1982-01-01

    This program aimed to modify existing commercial pressure vessel steels to provide strong, tough, creep resistant materials, with low hydrogen attack and temper embrittlement susceptibilities, which can also be field-fabricated into thick-section vessels for coal conversion systems. Emphasis was placed on determining the effects of Mn, Ni and Cr on the creep rupture and hydrogen attack susceptibilities of Cr-Mo steels. Hydrogen attack studies were also carried out on A533B and model alloy systems to investigate the role of alloy carbides in promoting resistance to hydrogen damage. Creep rupture fracture times were determined at 500, 560 and 600/sup 0/C for periods up to 2000 hours. The effects of cooling rate from the austenitizing temperature and tempering response on the microstructure of 3Cr-1Mo-1Mn-1Ni steel were studied. The carbide structures in all the alloy modifications were carefully characterized. Data were collected from preliminary weld bead-on-plate tests of A387 and temper embrittlement studies of A543 with mischmetal addition. The unloading compliance test technique for J/sub Ic/ measurements was completed for A533B specimens but shortage of material prevented testing of A387. The mechanical property, elevated temperature creep and hydrogen attack data suggested that addition of 0.75 Cr + 0.5 Mn + 1Ni was beneficial in reducing susceptibility to hydrogen damage but was detrimental to creep rupture properties. 44 figures, 14 tables.

  7. Investigation of the plastic fracture of high strength steels

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1972-01-01

    This investigation deals in detail with the three recognized stages of plastic fracture in high strength steels, namely, void initiation, void growth, and void coalescence. The particular steels under investigation include plates from both commercial purity and high purity heats of AISI 4340 and 18 Ni, 200 grade maraging steels. A scanning electron microscope equipped with an X-ray energy dispersive analyzer, together with observations made using light microscopy, revealed methods of improving the resistance of high strength steels to plastic fracture.

  8. Influence of crack depth on the fracture toughness of reactor pressure vessel steel

    SciTech Connect

    Theiss, T.J.; Bryson, J.W.

    1991-01-01

    The Heavy Section Steel Technology Program (HSST) at Oak Ridge National Laboratory (ORNL) is investigating the influence of flaw depth on the fracture toughness of reactor pressure vessel (RPV) steel. Recently, it has been shown that, in notched beam testing, shallow cracks tend to exhibit an elevated toughness as a result of a loss of constraint at the crack tip. The loss of constraint takes place when interaction occurs between the elastic-plastic crack-tip stress field and the specimen surface nearest the crack tip. An increased shallow-crack fracture toughness is of interest to the nuclear industry because probabilistic fracture-mechanics evaluations show that shallow flaws play a dominant role in the probability of vessel failure during postulated pressurized-thermal-shock (PTS) events. Tests have been performed on beam specimens loaded in 3-point bending using unirradiated reactor pressure vessel material (A533 B). Testing has been conducted using specimens with a constant beam depth (W = 94 mm) and within the lower transition region of the toughness curve for A533 B. Test results indicate a significantly higher fracture toughness associated with the shallow flaw specimens compared to the fracture toughness determined using deep-crack (a/W = 0.5) specimens. Test data also show little influence of thickness on the fracture toughness for the current test temperature ({minus}60{degree}C). 21 refs., 5 figs., 3 tabs.

  9. Investigation of underwater welding of steel

    SciTech Connect

    Shannon, G.J.; Watson, J.; Deans, W.F. . Dept. of Engineering)

    1994-12-01

    The preliminary underwater welding study described forms part of a European funded research program (EUREKA EU194) which involves a feasibility study into laser welding applications in the offshore oil industry. An investigation was undertaken using a 1.2 KW carbon dioxide laser for underwater butt welding of BS 4360 43A and 50D steel, in order to assess the quality of the welds and to achieve an understanding of the laser/water/material interaction. Using a high-speed camera, the temporal behavior of the melt pool and ''plasma'' dynamics surrounded by an aqueous environment were monitored. Experiments were undertaken to characterize the attenuation of the laser beam in the water as a function of various focal length optics and depth of water. The effect of energy input conditions on the weld bead appearance and mechanical properties were also examined. The interaction of the laser beam with water produced a wave-guiding mechanism in which the focused beam instantaneously vaporizes the water and directs the beam on to the workpiece. The underwater weld beads exhibited sound microstructures over a range of weld energy inputs, mainly due to the formation of a ''dry region'' during welding. Metallurgical analysis of the welds showed a slight increase in hardness, though other post-weld mechanical strengths were similar to in-air results.

  10. Investigation of the plastic fracture of high strength steels

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1972-01-01

    An investigation of the plastic fracture process to improve tensile strength in high strength steels is presented. Two generic types of steels are considered: a quenched and tempered grade and a maraging grade, in order to compare two different matrix microstructures. Each type of steel was studied in commercial grade purity and in special melted high purity form, low in residual and impurity elements. The specific alloys dealt with include AISI 4340 and 18 Ni, 200 grade maraging steel, both heat treated to the same yield strength level of approximately 200 ksi.

  11. Research Investigation of Armor Plate Steels

    DTIC Science & Technology

    1942-02-20

    location at which the ballistic limits were determined. Ballistic limits and average hardness values from the 16 duplicate plates are given in Table 10 ...OF ARMOR PLATE STEELS Plate Nuzuber %C %.Mn %Si %Ni. %Cr %Mo %cu *7111 .46 1.58 .20 . 10 /.20 7276 .50 1.07 .3o 7277 .39 .35 .23 7278 .47 .91 .26 7279...26 2.3/2.7 7328 .34 .89 .20 1.3/1.7 .35/.46 * 7329 .34 .88 .25 1.3/1.7 10 /.20 7330 .46 .86 .24 .25/.35 : 10 /.20 734 .46 .84 .29 W 5. 35 7341 .34 .94

  12. Insight on the inconsistencies of Barkhausen signal measurements for radiation damage on nuclear reactor steel

    SciTech Connect

    Barroso, Soraia Pirfo; Fitzpatrick, Michael E.; Gillemot, Ferenc; Horváth, Marta; Horváth, Ákos; Szekely, Richard

    2014-02-18

    This paper focuses on the use of magnetic measurements, using Barkhausen signals to determine the irradiation effects, attempting to predict fracture toughness changes on nuclear reactor structural materials and correlating these measurements to mechanical testing and microstructure. For this study, two types of nuclear reactor materials were investigated: one sensitive to irradiation effects, the JRQ IAEA's reference material (A533B- -type); and one resistant material, 15KH2MFA WWER's reactor pressure vessel steel. The samples were carefully identified within the original heat block, i.e. forged or rolled plate. These calibrated samples were irradiated at different neutron fluences up to 10{sup 23} n/m{sup 2}. We show how microstructural anisotropy can mask the irradiation effects in the magnetic measurements. A correlation between irradiation effects and the magnetic measurements is explained based on this study.

  13. 77 FR 58355 - Drawn Stainless Steel Sinks From the People's Republic of China: Countervailing Duty Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... International Trade Administration Drawn Stainless Steel Sinks From the People's Republic of China... Department'') initiated antidumping and countervailing duty investigations of drawn stainless steel sinks... countervailing duty determination.\\2\\ \\1\\ See Drawn Stainless Steel Sinks From the People's Republic of...

  14. Development of the magnescope as an instrument for in situ evaluation of steel components of nuclear systems

    SciTech Connect

    Jiles, D.C.; Bi, Y.; Biner, S.B.

    1997-08-01

    Fatigue damage causes continuous, cumulative microstructural changes in materials and the magnetic properties of steels are sensitive to these microstructural changes. The work therefore focused on the relationship between fatigue damage and the measured magnetic properties of different steels under a variety of fatigue conditions. The project also investigated the feasibility and applicability of magnetic inspection techniques for non-destructive evaluation of fatigue damage. From the results of a series of fatigue tests, conducted on different steels under both low-cycle and high-cycle fatigue conditions, the magnetic properties, such as coercivity, remanence and Barkhausen effect, were found to change systematically with fatigue damage. The magnetic properties showed significant changes, especially during early stage of the fatigue and also at the end of the fatigue lifetime. An approximately linear relationship between the mechanical modulus and magnetic remanence was observed and was explained by a model developed in this study to describe the dynamic changes in magnetic and mechanical properties. The results of this research demonstrated that magnetic measurements are suitable for non-destructive evaluation of fatigue damage in steels such as A533B steel and Cr-Mo steels. The magnetic measurement techniques have been incorporated into instrumentation for in-situ evaluation of steel structures and components.

  15. Investigation of aluminum-steel joint formed by explosion welding

    NASA Astrophysics Data System (ADS)

    Kovacs-Coskun, T.; Volgyi, B.; Sikari-Nagl, I.

    2015-04-01

    Explosion welding is a solid state welding process that is used for the metallurgical joining of metals. Explosion cladding can be used to join a wide variety of dissimilar or similar metals [1]. This process uses the controlled detonation of explosives to accelerate one or both of the constituent metals into each other in such a manner as to cause the collision to fuse them together [2]. In this study, bonding ability of aluminum and steel with explosion welding was investigated. Experimental studies, microscopy, microhardness, tensile and bend test showed out that, aluminum and steel could be bonded with a good quality of bonding properties with explosion welding.

  16. Investigate the magnetic behaviour of thermal treated carbon steel

    NASA Astrophysics Data System (ADS)

    Kanelopoulos, N. P.

    2016-03-01

    The present paper investigates the utilization of the magnetic hysteresis loops and Barkhausen Noise for the non-destructive characterization of annealed and quenched carbon steels samples. The resulting magnetic properties were further evaluated by examining the microstructure of the samples by using scanning electron microscopy.

  17. 77 FR 65712 - Circular Welded Carbon-Quality Steel Pipe From Vietnam; Termination of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Circular Welded Carbon-Quality Steel Pipe From Vietnam; Termination of Investigation AGENCY... investigation concerning circular welded carbon-quality steel pipe from Vietnam (investigation No....

  18. Dynamic J sub I-R Curve Testing of HY-130 Steel.

    DTIC Science & Technology

    1981-10-01

    286-292 (Nov 1974). 18. Joyce, J.A., "Application of the Key Curve Method to Determining J,-R Curves for A533B Steel," NUREG /CR- 1290 U.S. Nuclear...1 -R Curve of High Strength Steels," U.S. Nuclear Regulatory Commission Report NUREG /CR- 1813 (Nov 1980). 26 i26 , I gINITIAL DISTRIBUTION CENTER

  19. Investigation of Laser Peening Effects on Hydrogen Charged Stainless Steels

    SciTech Connect

    Zaleski, Tania M.

    2008-10-30

    Hydrogen-rich environments such as fuel cell reactors can exhibit damage caused by hydrogen permeation in the form of corrosion cracking by lowering tensile strength and decreasing material ductility. Coatings and liners have been investigated, but there were few shot-peening or laser peening studies referenced in the literature with respect to preventing hydrogen embrittlement. The surface compressive residual stress induced by laser peening had shown success in preventing stress corrosion cracking (SCC) for stainless steels in power plants. The question arose if the residual stresses induced by laser peening could delay the effects of hydrogen in a material. This study investigated the effect of laser peening on hydrogen penetration into metal alloys. Three areas were studied: laser peening, hydrogenation, and hydrogen detection. This study demonstrated that laser peening does not reduce the hydrogen permeation into a stainless steel surface nor does it prevent hydrogen embrittlement. The effect of laser peening to reduce hydrogen-assisted fatigue was unclear.

  20. Investigation of the permeability tensor of electrical steel sheet

    SciTech Connect

    Birkfeld, M.

    1998-09-01

    The permeability tensor is a mathematical model for the description of the electro-magnetic behavior of electrical silicon iron steel sheet under two-dimensional magnetizing conditions. In this paper, an interpretation of the properties of this tensor is given, the investigation of the tensor elements from measurements under two-dimensional magnetizing conditions is described, and some examples of measurements and the corresponding permeability tensor elements are indicated.

  1. Investigation of Mechanical Properties of Steel Fibre- Reinforced Concrete

    NASA Astrophysics Data System (ADS)

    Ryabchikov, A.; Tamme, V.; Laurson, M.

    2015-11-01

    Steel fibre-reinforced concrete (SFRC) is widely used in the structural elements of buildings: industrial floors, slabs, walls, foundation, etc. When a load is applied to a fibre- reinforced composite consisting of a low-modulus matrix reinforced with high-strength, high- modulus fibres, the plastic flow of the matrix under stress transfers the load to the fibre; this results in high-strength, high-modulus material which determines the stiffness and stress of the composite. In this study the equivalent flexural strength, equivalent flexural ratio Re,3 and the compressing strength of SFRC are investigated. Notched test specimens with five different dosages of steel fibres (20, 25, 30, 35, 40 kg/m3) were prepared using industrial concrete. Determination of flexural tension strength was carried out according to the EU norm EVS-EN 14651:2005+A1:2007. The equivalent flexural strength and subsequent equivalent flexural ratio Re,3 of SFRC with a dosage of 20, 25, 30, 35 kg/m3 similar to their average values and with a dosage of 40 kg/m3 were 31% higher than their average values. The compressive strength of the steel fibre-reinforced concrete was slightly higher compared to plain concrete, except specimens with the dosage of 40 kg/m3 where the increase was 30%.

  2. Investigations of low-temperature neutron embrittlement of ferritic steels

    SciTech Connect

    Farrell, K.; Mahmood, S.T.; Stoller, R.E.; Mansur, L.K.

    1992-12-31

    Investigations were made into reasons for accelerated embrittlement of surveillance specimens of ferritic steels irradiated at 50C at the High Flux Isotope Reactor (HFIR) pressure vessel. Major suspects for the precocious embrittlement were a highly thermalized neutron spectrum,a low displacement rate, and the impurities boron and copper. None of these were found guilty. A dosimetry measurement shows that the spectrum at a major surveillance site is not thermalized. A new model of matrix hardening due to point defect clusters indicates little effect of displacement rate at low irradiation temperature. Boron levels are measured at 1 wt ppM or less, inadequate for embrittlement. Copper at 0.3 wt % and nickel at 0.7 wt % are shown to promote radiation strengthening in iron binary alloys irradiated at 50 to 60C, but no dependence on copper and nickel was found in steels with 0.05 to 0.22% Cu and 0.07 to 3.3% Ni. It is argued that copper impurity is not responsible for the accelerated embrittlement of the HFIR surveillance specimens. The dosimetry experiment has revealed the possibility that the fast fluence for the surveillance specimens may be underestimated because the stainless steel monitors in the surveillance packages do not record an unexpected component of neutrons in the spectrum at energies just below their measurement thresholds of 2 to 3 MeV.

  3. Experimental investigations on steel-concrete composite columns for varying parameters

    NASA Astrophysics Data System (ADS)

    Aparna, V.; Vivek, D.; Neelima, Kancharla; Karthikeyan, B.

    2017-07-01

    In this study, the experimental investigations on steel tubes filled with different types of concrete are presented. Steel tubes filled with fibre reinforced concrete using lathe waste and steel tube with concerned confined with steel mesh were investigated. The combinations were compared with steel tubes with conventional concrete. A total of 4 concrete filled steel tube (CFST) combinations were made with tubes of diameter 100 mm with wall thickness 1.6 mm and a height of 300 mm. Axial compression test to examine the resisting capacity of the columns and push-out test for noting the bond strength were performed. Coupon tests were also conducted to determine the mechanical properties of steel. The structural behaviour of the composite columns was evaluated from on the test results. It was observed that steel tube filled fibre reinforced possessed better bond strength and resistance to axial load.

  4. Tribological investigation of diamond nanoparticles for steel/steel contacts in boundary lubrication regime

    NASA Astrophysics Data System (ADS)

    Raina, Ankush; Anand, Ankush

    2017-08-01

    This paper presents an investigation of nanodiamond additives (ND) in combination with copper oxide (CuO) and hexagonal boron nitride (h-BN) particles mixed in PAO (poly-alpha-olefin) oil. The experimentation was performed for a ball on disc configuration using steel/steel contacts in the boundary lubrication regime. The loads were varied from 20 to 100 N and sliding velocity was kept constant at 0.58 m/s. The wear behavior was evaluated using SEM images of the worn-out disc surfaces. EDS analysis of the samples was performed to find out the chemical content of the worn surfaces. Results obtained therein demonstrated that oil containing CuO/ND and h-BN/ND exhibited better frictional and wear characteristics. For CuO/ND containing lubricant, the maximum decrease in friction coefficient is 15.45% in comparison to the CuO oil, whereas for h-BN/ND containing additives the overall decrease is 25.45%. It was observed that the combined effect of CuO/ND and h-BN/ND due to their intrinsic characteristics led to the overall improvement in lubrication properties of the base oil.

  5. Cylindrical Shells Made of Stainless Steel - Investigation of Postbuckling

    NASA Astrophysics Data System (ADS)

    Stehr, Sebastian; Stranghöner, Natalie

    2017-06-01

    The relevant load case of open thin-walled shells is often wind loading during construction. Because of the missing stabilization effect of the roof they show a very high sensitivity to buckling which results into higher wall thicknesses. As part of the European RFCS research project BiogaSS the Institute for Metal and Lightweight Structures of the University of Duisburg-Essen carried out investigations on open thin-walled tanks made of austenitic and duplex stainless steels under wind load to study a possible economic advantage which might be gained from the consideration of the elastic postbuckling behaviour. This contribution presents not only experimental and numerical results but also first recommendations regarding the range of possible buckling reduction factors which might be incorporated in future revisions of EN 1993-1-6 and EN 1993-4-2.

  6. Investigation of Steels for Improved Weldability in Ship Construction.

    DTIC Science & Technology

    1984-05-01

    transformation products from Widmanstatten ferrite, pearlite, and bainite to a more equiaxed ferrite and pearlite microstructure. Additions of residuals (Cu + Ni...ferrite and the type of AL.. microconstituents present (pearlite, bainite , or martensite). Microstructures of the HAZ’s of all the steels after simulated...martensite and bainite . The final group of steels all contained vanadium. Th’. plain vanadium steel V1 had a slightly higher CVN transition temperature

  7. Microanalysis investigations of transformation toughened Co-Ni steels

    NASA Astrophysics Data System (ADS)

    Lippard, Henry Edward

    1999-11-01

    The evolution of the structural subsystems in secondary hardening cobalt-nickel steels was observed as function of tempering treatments with a special emphasis on the austenite dispersion in the AerMet100 alloy. The transformation toughening effectiveness was correlated with the austenite morphology and composition as a function of two-step nucleation and growth heat treatments. The co-location of the austenite precipitates with the M2C carbide particles indicated a coupling by sequential nucleation of the two second phase dispersions. The necessity of the M2C carbide dispersion to provide nucleation sites for austenite precipitation was shown in an investigation of a Fe-15Co-10Ni ternary alloy that did not produce an austenite dispersion. The optimal austenite dispersion for transformation toughening in AerMet100 consisted of 8 nm intralath precipitates with a 42 wt% nickel composition. A technique to extract the precipitate composition information from a precipitate embedded in a matrix was developed using a scanning transmission electron microscope (STEM), an energy dispersive spectroscopy (EDS) detector, and a parallel electron energy loss (PEELS) detector. The validity of the microanalysis technique was confirmed by Monte Carlo modeling of x-ray emission from precipitate-matrix systems corresponding to those encountered in this investigation. The experimental microanalytical data from AerMet100 was used to develop precipitation models for the interlath austenite films and the intralath austenite particle dispersion. The three phase unstable thermodynamic model incorporating capillary energy additions for the austenite and M2C arbide particles successfully simulated the system evolution. The austenite interfacial energy was measured at 439 mJ/m2 and the capillary energy corresponding to the optimal austenite dispersion for transformation toughening was 1200 J/mol. The knowledge gained from this investigation was used to design a new cobaltnickel secondary

  8. Investigation and Modeling of Recrystallization of Cold Rolled Automotive Steels

    NASA Astrophysics Data System (ADS)

    Zhitelev, P.; Vasilyev, A.; Sokolov, S.; Sokolov, D.; Paligin, R.

    2016-04-01

    Ferrite recrystallization in cold-rolled sheets of automotive steels has been studied using a Geeble 3800 complex. Mathematical models for quantitative description of the process kinetics and prediction of the recrystallized ferrite grain size have been developed. These models enable performing calculations for any arbitrary heating regimes, including those that are used in industrial production practice, and allow taking into account the effects of a fairly wide range variation of the chemical composition of steels.

  9. An investigation into the behaviour of steel proprietary support structures

    NASA Astrophysics Data System (ADS)

    Wilkinson, Simon James

    Thin walled cold-formed steel components have favourable strength-to-weight, and strength-to-cost ratios. Unfortunately, classical structural theory cannot be utilised for many of the inherently complex non-uniform components available. The finite element method (FE) was adopted to provide a numerical approximation for a number of cold-formed structural fabrications. An orthogonally stiffened steel sandwich panel was modelled using a linear-elastic FE formulation, and benchmarked against full-scale laboratory test data. An accurate estimation of the stress state was only achieved after the interaction between the discrete support restraint and method of load application was appropriately defined. A more exhaustive investigation was carried out on column stability problems. The generalised eigenvalue extraction method within the FE formulation was adopted. For standard prismatic section geometries, the modal shape and critical load capacity, for both first, and higher order modes, with various end restraint conditions was predicted with a high degree of accuracy. In addition, a perforated cellular twin-web column was modelled. Its inherent non-uniform cross-section was transformed into an equivalent uniform cross-section with a missing central strip in the two symmetrical webs. Furthermore, the effective moment of inertia calculated for a particular pitch and hole diameter was independent of length. The effect of diaphragm plates on the structural performance of spaced, or battened types of column was investigated, and found that diaphragm joint rigidity substantially enhanced buckling capacity. Furthermore, even if the joints are only pinned, the end-plate stiffness still significantly increases buckling capacity. The FE formulation was adopted to evaluate the elastic critical load, and the moment of inertia of a proprietary soldier section. The study showed that the effective moment of inertia was dependent on length. A linear elastic beam formulation was adopted

  10. Investigation of hot cracking resistance of 2205 duplex steel

    NASA Astrophysics Data System (ADS)

    Adamiec, J.; Ścibisz, B.

    2010-02-01

    Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the Rfparameter (Rf = (Tliquidus - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 °C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of TL = 1465 °C and a solidus temperature of TS = 1454 °C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 °C. As the value of the NDT temperature 1367 °C was applied while for DRT the assumed temperature was 1375 °C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

  11. Investigation of the Mechanism of Fatigue of Cold-Worked Steel Alloys

    DTIC Science & Technology

    2007-11-02

    treatment are subjected to the fatigue process. Therefore, it is of interest to conduct x-ray investigations of the changes in the crystalline structure of superficially cold-worked steels subjected to alternating loads.

  12. Investigation of corrosion of welded joints of austenitic and duplex stainless steels

    NASA Astrophysics Data System (ADS)

    Topolska, S.

    2016-08-01

    Investigation of corrosion resistance of materials is one of the most important tests that allow determining their functional properties. Among these tests the special group consist electrochemical investigations, which let to accelerate the course of the process. These investigations allow rapidly estimating corrosion processes occurring in metal elements under the influence of the analysed environment. In the paper are presented results of investigations of the resistance to pitting corrosion of the steel of next grades: austenitic 316L and duplex 2205. It was also analysed the corrosion resistance of welded joints of these grades of steel. The investigations were conducted in two different corrosion environments: in the neutral one (3.5 % sodium chloride) and in the aggressive one (0.1 M sulphuric acid VI). The obtained results indicate different resistance of analysed grades of steel and their welded joints in relation to the corrosion environment. The austenitic 316L steel characterizes by the higher resistance to the pitting corrosion in the aggressive environment then the duplex 2205 steel. In the paper are presented results of potentiodynamic tests. They showed that all the specimens are less resistant to pitting corrosion in the environment of sulphuric acid (VI) than in the sodium chloride one. The 2205 steel has higher corrosion resistance than the 316L stainless steel in 3.5% NaCl. On the other hand, in 0.1 M H2SO4, the 316L steel has a higher corrosion resistance than the 2205 one. The weld has a similar, very good resistance to pitting corrosion like both steels.

  13. Investigation on frictional characteristics and drawbead restraining force of steel with/without coating

    NASA Astrophysics Data System (ADS)

    Chen, Lianfeng; Zheng, Tianran; Chen, Qing; Zhang, Jun

    2013-12-01

    Advanced high strength steels (AHSS) are used more and more in automotive industry for increasing crashworthiness and weight reduction. Improving metal flow and reduce friction are important to forming the part and decrease part reject rates of AHSS. The present study focused on friction characteristics and drawbead restraining force of Dual Phase (DP) steels with or without coating, such as DP980, DP780, DP590, DP780+Z, DP780+ZF, DP590+Z, using experimental approach. The effect of material properties, temperature, sliding velocity, surface roughness, dry and lubricant on friction behavior of DP steels is investigated. The contrast of DP steels with mild IF steel is carried out. The restraining force draw through different radius of drawbead is evaluated. This study is benefit to the set up of technique parameters during sheet metal forming simulation.

  14. Investigations on the sintering response of steel-ceramic composites

    NASA Astrophysics Data System (ADS)

    Baumgart, C.; Weigelt, C.; Krüger, L.; Aneziris, C. G.

    2016-07-01

    Purpose of this article is the evaluation of the influence of sintering parameters on the microstructure evolution and mechanical properties of pressureless sintered metal matrix composites consisting of metastable 16Cr7Mn7Ni-steel with 0 or 5 vol.% magnesia partially stabilized zirconia (Mg-PSZ) particles. The materials were prepared from powder raw materials via extrusion at ambient temperature. Three different temperatures between 1280 °C and 1380 °C and two varying dwell times of 40 min and 120 min at maximum temperature were applied. Both, tensile and compression tests are conducted at quasi-static strain rates for comparison of strength level, deformability and energy absorption capability. The results are discussed with regard to the porosity of the specimens, the interface between steel and ceramic, the TRansformation Induced Plasticity (TRIP)-effect occurrence and the failure behavior.

  15. Lifetest investigations with stainless steel/water heat pipes

    NASA Astrophysics Data System (ADS)

    Muenzel, W. D.; Kraehling, H.

    Life tests were conducted on water heat pipes, made from four different alloys of stainless steel, at operation temperatures of 120, 160, 220, and 320 C in a reflux boiler mode for more than 20,000 hr. Other parameters varied during the tests included capillary structure, pretreatment and cleaning of the components, additional oxidation of the inner surface, filling procedures, amoung of liquid change, the number of ventings, and the duration of the reaction runs. The best results were obtained with pipes containing stainless steels with molybdenum alloy additions and with carbon contents of greater than 0.03%; with components which formed a protective surface layer; with the use of double-distilled water that had been ultrasonically degassed; with repeated ventings during the initial reaction run of 500 hr minimum duration; and with the addition of gaseous oxygen into the heat pipe during the reaction run with subsequent venting.

  16. An experimental investigation of thermal stress relief in two steels

    SciTech Connect

    Cammett, J.T.; Luken, R.C.; Dotson, R.D.

    1995-12-01

    Thermal relief of residual stresses was studied in AISI 4340 alloy steel (38 HRC) and AISI 1070 spring steel (45 HRC). Residual Stresses in simple strip-geometry specimens introduced by shot peening, abusive grinding, and mechanical bending were measured by X-ray diffraction before and after thermal treatments for varying times over the temperature range of 375 F to 1,050 F. Results correlated well with a time-temperature parameter having the same form as the Larson-Miller parameter commonly used to correlate creep deformation and stress-rupture behavior of metallic materials. Thermal stress relief results exhibited not only a material dependence, but also an apparent dependence on the initial magnitude of residual stress before thermal treatment and, possibly, on the manner of their creation.

  17. Neutron diffraction investigation of lattice microstrain in ferrite steel

    NASA Astrophysics Data System (ADS)

    Camanzi, A.; Moze, O.

    1992-06-01

    The degradation of carbon steels when exposed to H rich environments is well known to result in catastrophic failure. In order to characterize in a comprehensive manner the structural effects of hydrogenation, a series of high resolution neutron powder diffraction measurements were carried out on cross-sections of carbon steel segments used for gas pipelines. Peak positions were measured to an accuracy of 0.001%, whilst line broadening of individual peaks was measured to an accuracy of 0.1%. The ( h k l) dependent peak linewidths were fitted using a pseudo-Voigt peak shape function. Non-hydrogenated materials were found to display a different diffraction linewidth dependence on the crystal elastic anisotropy than hydrogenated materials.

  18. Investigation of plastic deformation heterogeneities in duplex steel by EBSD

    SciTech Connect

    Wronski, S.; Tarasiuk, J.; Bacroix, B.; Baczmanski, A.; Braham, C.

    2012-11-15

    An EBSD analysis of a duplex steel (austeno-ferritic) deformed in tension up to fracture is presented. The main purpose of the paper is to describe, qualitatively and quantitatively, the differences in the behavior of the two phases during plastic deformation. In order to do so, several topological maps are measured on the deformed state using the electron backscatter diffraction technique. Distributions of grain size, misorientation, image quality factor and texture are then analyzed in detail. - Highlights: Black-Right-Pointing-Pointer Heterogeneities in duplex steel is studied. Black-Right-Pointing-Pointer The behavior of the two phases during plastic deformation is studied. Black-Right-Pointing-Pointer IQ factor distribution and misorientation characteristics are examined using EBSD.

  19. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    NASA Astrophysics Data System (ADS)

    Jana, S.; Hovanski, Y.; Grant, G. J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining magnesium alloy AZ31 sheet to galvanized steel sheet in a lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential: a 0.8 mm thick, electrogalvanized (EG) mild steel, and a 1.5 mm thick hot-dipped galvanized (HDG) high-strength, low-alloy (HSLA) steel. These steels were joined to 2.33 mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and the process parameters were kept the same. The average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating present on the steel sheets, and subsequent alloying with the Mg sheet resulted in the formation of a solidified Zn-Mg alloy layer.

  20. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining Magnesium alloy AZ31 sheet to galvanized steel sheet in lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential; a 0.8mm thick, electro galvanized (EG) mild steel, and a 1.5mm thick hot dipped galvanized (HDG) high-strength, low-alloy steel (HSLA). These steels were joined to 2.33mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and process parameters were kept the same. Average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating at the interface and subsequent alloying with the Mg sheet resulting in formation of solidified Zn-Mg alloy layer at AZ31/steel interface.

  1. An experimental investigation of energy absorption in TRIP steel under impact three-point bending deformation

    NASA Astrophysics Data System (ADS)

    Pham, Hang; Iwamoto, Takeshi

    2015-09-01

    TRIP (Transformation-induced Plasticity) steel is nowadays in widespread use in the automobile industry because of their favorable mechanical properties such as high strength, excellent formability and toughness because of strain-induced martensitic transformation. Moreover, when TRIP steel is applied to the components of the vehicles, it is expected that huge amount of kinetic energy will be absorbed into both plastic deformation and martensitic transformation during the collision. Basically, bending deformation due to buckling is one of the major crash deformation modes of automobile structures. Thus, an investigation of energy absorption during bending deformation at high impact velocity for TRIP steel is indispensable. Although TRIP steel have particularly attracted the recent interest of the scientific community, just few studies can be found on the energy absorption characteristic of TRIP steel, especially at impact loading condition. In present study, experimental investigations of bending deformation behaviors of TRIP steel are conducted in the three-point bending tests for both smooth and pre-cracked specimen. Then, energy absorption characteristic during plastic deformation and fracture process at high impact velocity in TRIP steel will be discussed.

  2. Investigating the effect of heat treatment on hydrogen permeation behavior of API X-70 steel

    NASA Astrophysics Data System (ADS)

    Shirband, Zeynab; Shishesaz, Mohammad Reza; Ashrafi, Ali

    2012-06-01

    Pipeline steels absorb different amounts of hydrogen during transportation of sour oil and gas. Since hydrogen-related damages such as hydrogen-induced cracking are strongly affected by hydrogen permeation behavior of steels, the purpose of this study determined to investigate hydrogen permeation behavior in API X-70 pipeline steel using electrochemical permeation method. The effect of heat treatment was also considered. It was found that hydrogen diffusivity increased by annealing the X-70 and it was decreased by normalizing. The condition was reverse for hydrogen apparent solubility. Finally, it was concluded that change in hydrogen diffusivity can be attributed to changes in grain size due to heat treatment.

  3. A Numerical Investigation of CFRP-Steel Interfacial Failure with Material Point Method

    SciTech Connect

    Shen Luming; Faleh, Haydar; Al-Mahaidi, Riadh

    2010-05-21

    The success of retrofitting steel structures by using the Carbon Fibre Reinforced Polymers (CFRP) significantly depends on the performance and integrity of CFRP-steel joint and the effectiveness of the adhesive used. Many of the previous numerical studies focused on the design and structural performance of the CFRP-steel system and neglected the mechanical responses of adhesive layer, which results in the lack of understanding in how the adhesive layer between the CFRP and steel performs during the loading and failure stages. Based on the recent observation on the failure of CFRP-steel bond in the double lap shear tests, a numerical approach is proposed in this study to simulate the delamination process of CFRP sheet from steel plate using the Material Point Method (MPM). In the proposed approach, an elastoplasticity model with a linear hardening and softening law is used to model the epoxy layer. The MPM, which does not employ fixed mesh-connectivity, is employed as a robust spatial discretization method to accommodate the multi-scale discontinuities involved in the CFRP-steel bond failure process. To demonstrate the potential of the proposed approach, a parametric study is conducted to investigate the effects of bond length and loading rates on the capacity and failure modes of CFRP-steel system. The evolution of the CFRP-steel bond failure and the distribution of stress and strain along bond length direction will be presented. The simulation results not only well match the available experimental data but also provide a better understanding on the physics behind the CFRP sheet delamination process.

  4. A Numerical Investigation of CFRP-Steel Interfacial Failure with Material Point Method

    NASA Astrophysics Data System (ADS)

    Shen, Luming; Faleh, Haydar; Al-Mahaidi, Riadh

    2010-05-01

    The success of retrofitting steel structures by using the Carbon Fibre Reinforced Polymers (CFRP) significantly depends on the performance and integrity of CFRP-steel joint and the effectiveness of the adhesive used. Many of the previous numerical studies focused on the design and structural performance of the CFRP-steel system and neglected the mechanical responses of adhesive layer, which results in the lack of understanding in how the adhesive layer between the CFRP and steel performs during the loading and failure stages. Based on the recent observation on the failure of CFRP-steel bond in the double lap shear tests [1], a numerical approach is proposed in this study to simulate the delamination process of CFRP sheet from steel plate using the Material Point Method (MPM). In the proposed approach, an elastoplasticity model with a linear hardening and softening law is used to model the epoxy layer. The MPM [2], which does not employ fixed mesh-connectivity, is employed as a robust spatial discretization method to accommodate the multi-scale discontinuities involved in the CFRP-steel bond failure process. To demonstrate the potential of the proposed approach, a parametric study is conducted to investigate the effects of bond length and loading rates on the capacity and failure modes of CFRP-steel system. The evolution of the CFRP-steel bond failure and the distribution of stress and strain along bond length direction will be presented. The simulation results not only well match the available experimental data but also provide a better understanding on the physics behind the CFRP sheet delamination process.

  5. Numerical investigation into thermal load responses of steel railway bridge

    NASA Astrophysics Data System (ADS)

    Saravana Raja Mohan, K.; Sreemathy, J. R.; Saravanan, U.

    2017-07-01

    Bridge design requires consideration of the effects produced by temperature variations and the resultant thermal gradients in the structure. Temperature fluctuation leads to expansion and contraction of bridges and these movements are taken care by providing expansion joints and bearings. Free movements of a member can be restrained by imposing certain boundary condition but at the same time considerable allowances should be made for the stresses resulting from this restrained condition since the additional deformations and stresses produced may affect the ultimate and serviceability limit states of the structure. If the reaction force generated by the restraints is very large, then its omission can lead to unsafe design. The principal objective of this research is to study the effects of temperature variation on stresses and deflection in a steel railway bridge. A numerical model, based on finite element analysis is presented for evaluating the thermal performance of the bridge. The selected bridge is analyzed and the temperature field distribution and the corresponding thermal stresses and strains are calculated using the finite element software ABAQUS. A thorough understanding of the thermal load responses of a structure will result in safer and dependable design practices.

  6. Crack tip microsampling and growth rate measurements in a 0.021%S low alloy steel in high temperature water

    SciTech Connect

    Young, L.M.; Andresen, P.L.

    1995-12-31

    The concentration of crack tip sulfur species and the corresponding crack growth rates are examined during the environmental assisted cracking of a low alloy steel in high temperature, high purity water. A novel microsampling technique is used to quantify the crack tip chemistry in a growing crack in parallel with measurements of crack growth rate under various environmental conditions. The present study investigates the dissolved crack tip sulfur content of a medium sulfur (0.021wt%) A533B low alloy steel compact tension specimen and the effects of corrosion potential, fatigue loading frequency, bulk sulfate additions, and sampling flow rate. Results are compared with previously published crack tip chemistries collected from a lower sulfur (0.013%) steel in the same environment. Findings indicate that, for both steels, high corrosion potential (oxygenated) conditions correspond with high crack growth rates and high dissolved crack tip sulfur species. In comparison, low corrosion potential produce both low crack growth rates and low dissolved sulfur levels at the crack tip. Both materials exhibit somewhat lower dissolved sulfur levels and lower corresponding crack growth rates when the cyclic loading frequency is decreased from 10{sup {minus}4} to 10{sup {minus}5} Hz, although environmentally enhanced growth rates are still observed. Crack tip microsamples collected during bulk sulfate additions and nitrogen deaerated conditions show higher crack tip concentrations than the simple additive contribution of the prior crack tip sulfur level plus the bulk H{sub 2}SO{sub 4} level. This finding indicates that it is not the potential gradient, per se, which enhances crack tip dissolution, but the aggressive chemistry in the crack.

  7. Experimental and Theoretical Investigations of Hot Isostatically Pressed-Produced Stainless Steel/High Alloy Tool Steel Compound Materials

    NASA Astrophysics Data System (ADS)

    Lindwall, Greta; Flyg, Jesper; Frisk, Karin; Sandberg, Odd

    2011-05-01

    Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop-electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.

  8. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of MIL A46100 Armor-Grade Steel: A Computational Investigation

    DTIC Science & Technology

    2014-06-12

    distribution is unlimited. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor- Grade Steel : A Computational Investigation The views...Welds of Mil A46100 Armor- Grade Steel : A Computational Investigation Report Title In our recent work, a multi-physics computational model for the...utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor- grade martensitic steel

  9. Model Investigations on the Stability of the Steel-Slag Interface in Continuous-Casting Process

    NASA Astrophysics Data System (ADS)

    Hagemann, René; Schwarze, Rüdiger; Heller, Hans P.; Scheller, Piotr R.

    2013-02-01

    In the continuous-casting mold, the mold powder in contact with the liquid steel surface forms a liquid slag layer. The flow along the steel-slag interface generates shear stress at the interface, waves, and leads to fingerlike protrusions of liquid slag into steel. Reaching a critical flow velocity and thereby shear stress, the protrusions can disintegrate into slag droplets following the flow in the liquid steel pool. These entrained droplets can form finally nonmetallic inclusions in steel material, cause defects in the final product, and therefore, should be avoided. In the current work, the stability of a liquid-liquid interface without mass transfer between phases was investigated in cold model study using a single-roller driven flow in oil-water systems with various oil properties. Applying the similarity theory, two dimensionless numbers were identified, viz. capillary number Ca and the ratio of kinematic viscosities ν 1/ ν 2, which are suitable to describe the force balance for the problem treated. The critical values of the dimensionless capillary number Ca* marking the start of lighter phase entrainment into the heavier fluid, are determined over a wide range of fluid properties. The dimensionless number ν 1/ ν 2 was defined as the ratio of kinematic viscosities of the lighter phase ν 1 and heavier phase ν 2. The ratios of kinematic viscosities of different steel-slag systems were calculated using measured thermophysical properties. With the knowledge of thermophysical properties of steel-slag systems, Ca* for slag entrainment as a function of v 1/ v 2 is derived. Assuming no reaction between the phases and no interfacial flow, slag entrainment should not occur under the usual casting conditions.

  10. Investigating early stages of biocorrosion with XPS: AISI 304 stainless steel exposed to Burkholderia species

    NASA Astrophysics Data System (ADS)

    Johansson, Leena-Sisko; Saastamoinen, Tuomas

    1999-04-01

    We have investigated the interactions of an exopolymer-producing bacteria, Burkholderia sp. with polished AISI 304 stainless steel substrates using X-ray photoelectron spectroscopy (XPS). Steel coupons were exposed to the pure bacteria culture in a specially designed flowcell for 6 h during which the experiment was monitored in situ with an optical microscope. XPS results verified the formation of biofilm containing extracellular polymer on all the samples exposed to bacteria. Sputter results indicated that some ions needed for metabolic processes were trapped within the biofilm. Changes in the relative Fe concentration and Fe 2p peak shape indicated that also iron had accumulated into the biofilm.

  11. An Investigation of Stress-Corrosion Cracking Susceptibility in Candidate Steels for Tension Leg Platform Tendons.

    DTIC Science & Technology

    1986-04-24

    5773 An Investigation of Stress-Corrosion Cracking Susceptibility in Candidate Steels for Tension Leg Platform Tendons I. A. HAUSER II AND T. W. CROOKER... Tendons 13a, TYPE OF REPORT 1 3b. TIME COVERED 14. DATE OF REPORT (YWV MotDy) rS. PAGE COUNT ItrmFROM 10to M 1986 Apri 24 16 1SUPPLEMENTARY NOTATION...structural integrity of high- strength steel TLP tendons currently being considered for offshore application in U.S. coastal waters. 20. DISTRIBUTION

  12. Further investigations into the N-demethylation of oripavine using iron and stainless steel.

    PubMed

    Kok, Gaik B; Scammells, Peter J

    2011-02-21

    Further investigations into the direct synthesis of N-nororipavine from oripavine using iron powder under non-classical Polonovski conditions have been conducted. The stoichiometry, solvents and iron oxidation rates were found to have a dramatic effect on the rate of N-demethylation as well as product yield. Herein, we also present high-yield access to the N-demethylated product simply by employing stainless steel rather than iron powder as redox catalyst. To our knowledge, this is the first time stainless steel has been used to moderate the redox chemistry of iron in organic synthesis.

  13. An investigation of the plastic fracture of high strength steels. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1973-01-01

    Three generally recognized stages of plastic fracture in high strength steels are considered in detail. These stages consist of void initiation, void growth, and void coalescence. A brief review of the existing literature on plastic fracture is included along with an outline of the experimental approach used in the investigation.

  14. Investigation on laser brazing AA6056 Al alloy to XC18 low-carbon steel

    NASA Astrophysics Data System (ADS)

    Ding, Jianjun; Li, Feiqun; Qu, Feng; Peyre, Patrice; Fabbro, Remy

    2005-01-01

    Based on the studies of influence of YAG laser heating conditions for Al alloy melt and steel on wettability, the mechanics of the laser overlap braze welding of 6056 Al and XC18 steel sheet has been investigated. Under the temperature range which is above the melting point of the Al alloy and below the melting point of the steel, two dissimilar metals can be joined by means of laser braze welding. There is no crack observed in the joining area, i.e. Al-Fe intermetallic phase (Fe3Al/FeAl/FeAl3/Fe2Al5) layer formed by solution and diffusion between liquid-solid interface. The temperature range can be defined as the process temperatures of laser braze welding of Al-Fe materials. Selecting a higher laser heating temperature can improve the wettability of Al melt to steel surface, but the intermetallic phase layer is also thicker. When the laser heating temperature is so high that the joining surface of steel is melted, there is a crack trend in the joining area.

  15. Investigation of newly developed added damping and stiffness device with low yield strength steel.

    PubMed

    Shih, Ming-Hsiang; Sung, Wen-Pei; Go, Cheer-Germ

    2004-03-01

    Energy dissipators, isolated-resistant and specific structural forms for earthquake resistance are popular topics in the research to improve shock-resistance. In this work, experimental methods were used to investigate the property of low yield strength steel. Carbon content in LYS material is lower than that in other steels; the ultimate stress is three times the yield stress. The ultimate elongation rate is about 62% and the ductility is 2-3 times that of A36 steel. In order to overcome some defects of ordinary use metallic dampers, the mechanical characteristic of low yield strength steel is used to develop added damping and stiffness for rhombic steel plate absorber. Test of the energy dissipation behavior for this newly developed device indicated that LYS could stably dissipate or absorb the input energy of earthquake. Then, the analytical model for the hysteretic behavior of this new device is proposed. Comparison of experimental data and numerical simulation results showed that this analytical model is suitable for simulating the hysteretic energy behavior of this new device.

  16. Numerical Investigation on Cold-Formed Steel Lipped Channel Columns with Intermediate Web Stiffeners

    NASA Astrophysics Data System (ADS)

    Manikandan, P.; Arun, N.

    2016-03-01

    This work describes finite element simulation into the ultimate strength and buckling behaviour of cold-formed steel lipped channel columns with intermediate web stiffeners subjected to axial compression. Numerical simulation is performed by using finite element analysis software ANSYS. A reliable finite element model is used for the parametric study of effects of cross section geometries on the ultimate strength and buckling behaviour of cold-formed steel columns are investigated. All the section geometries in this study also satisfied the limitations given for pre-qualified sections in direct strength method. The cross sectional dimensions, section properties and length of the specimen are obtained by using CUFSM software. The ultimate strength predicted by the finite element analysis are compared with the strength calculated using the current direct strength method specifications for cold-formed steel structures, suitable design recommendations are proposed.

  17. Comparative investigation of corrosion resistance of steel reinforcement in alinite and Portland cement mortars

    SciTech Connect

    Kostogloudis, G.C.; Kalogridis, D.; Ftikos, C.; Malami, C.; Georgali, B.; Kaloidas, V.

    1998-07-01

    The corrosion resistance of steel-reinforced mortar specimens made from alinite cement was investigated using ordinary Portland cement (OPC) specimens as reference. The specimens were prepared and exposed in three different environments: continuous exposure in tap water, interrupted exposure in tap water, and interrupted exposure in 3.5% NaCl solution. The steel weight loss and the half cell potential were measured vs. exposure time, up to the age of 12 months. Pore solution extraction and analysis and porosity determination were also performed. In continuous exposure in tap water, alinite cement provided adequate protection against corrosion. In interrupted exposure in tap water, a higher corrosion was observed for alinite cement compared to OPC. In the case of interrupted exposure in 3.5% NaCl solution, the simultaneous action of free chlorides and oxygen resulted in the depassivation of steel reinforcing bars in alinite and Portland cement mortars, and led to severe corrosion effect.

  18. Investigations on the Suitability of Coated Steel Piping System for High Pressure Seawater Reverse Osmosis Application

    NASA Astrophysics Data System (ADS)

    Mobin, Mohammad

    2010-03-01

    This study deals with the investigations concerning with the suitability of coated steel piping system as an economically viable alternative to costly stainless steel piping for high pressure seawater reverse osmosis (SWRO) application. The piping system selected for investigation is a carbon steel piping coated internally and externally with thermoplastic coating (coating powder Plascoat PPA 571). The performance of thermoplastic coating was investigated by conducting SWRO pilot plant test, salt spray test, mechanical tests and testing of the coating under crevices (both in pilot plant and laboratory), and for leachable organics and inorganics (both in laboratory and pilot plant test). The testing of coating in the pilot plant resulted in the formation of some blisters on the internal surface of the pipes. The blisters were broken causing the corrosion of underneath steel. The coating showed a poor resistance to salt fog test. In general, the coating performed satisfactorily under the crevices but showed blistering on either side of the test panels. The adhesive strength of the coating was found to be poor; however, it showed good flexibility. The results of chemical analysis did not show the leaching of organic or inorganic pollutants from the coating.

  19. Investigation of Forming Performance of Laminated Steel Sheets Using Finite Element Analyses

    SciTech Connect

    Liu Wenning; Sun Xin; Ruokolainen, Robert; Gayden Xiaohong

    2007-05-17

    Laminated steel sheets have been used in automotive structures for reducing in-cabin noise. However, due to the marked difference in material properties of the different laminated layers, integrating laminated steel parts into the manufacturing processes can be challenging. Especially, the behavior of laminated sheets during forming processes is very different from that of monolithic steel sheets. During the deep-draw forming process, large shear deformation and corresponding high interfacial stress may initiate and propagate interfacial cracks between the core polymer and the metal skin, hence degrading the performance of the laminated sheets. In this paper, the formability of the laminated steel sheets is investigated by means of numerical analysis. The goal of this work is to gain insight into the relationship between the individual properties of the laminated sheet layers and the corresponding formability of the laminated sheet as a whole, eventually leading to reliable design and successful forming process development of such materials. Finite element analyses of laminate sheet forming are presented. Effects of polymer core thickness and viscoelastic properties of the polymer core, as well as punching velocity, are also investigated.

  20. Investigation of Forming Performance of Laminated Steel Sheets Using Finite Element Analyses

    SciTech Connect

    Liu, Wenning; Sun, Xin; Ruokolainen, Robert; Gayden, X.

    2007-06-20

    Laminated steel sheets have been used in automotive structures for reducing in-cabin noise. However, due to the marked difference in material properties of the different laminated layers, integrating laminated steel parts into the manufacturing processes can be challenging. Especially, the behavior of laminated sheets during forming processes is very different from that of monolithic steel sheets. During the deep-draw forming process, large shear deformation and corresponding high interfacial stress may initiate and propagate interfacial cracks between the core polymer and the metal skin, hence degrading the performance of the laminated sheets. In this paper, the formability of the laminated steel sheets is investigated by means of numerical analysis. The goal of this work is to gain insight into the relationship between the individual properties of the laminated sheet layers and the corresponding formability of the laminated sheet as a whole, eventually leading to reliable design and successful forming process development of such materials. Finite element analyses of laminate sheet forming are presented. Effects of polymer core thickness and viscoelastic properties of the polymer core, as well as punching velocity, are also investigated.

  1. Investigation of Forming Performance of Laminated Steel Sheets Using Finite Element Analyses

    NASA Astrophysics Data System (ADS)

    Liu, Wenning; Sun, Xin; Ruokolainen, Robert; Gayden, Xiaohong

    2007-05-01

    Laminated steel sheets have been used in automotive structures for reducing in-cabin noise. However, due to the marked difference in material properties of the different laminated layers, integrating laminated steel parts into the manufacturing processes can be challenging. Especially, the behavior of laminated sheets during forming processes is very different from that of monolithic steel sheets. During the deep-draw forming process, large shear deformation and corresponding high interfacial stress may initiate and propagate interfacial cracks between the core polymer and the metal skin, hence degrading the performance of the laminated sheets. In this paper, the formability of the laminated steel sheets is investigated by means of numerical analysis. The goal of this work is to gain insight into the relationship between the individual properties of the laminated sheet layers and the corresponding formability of the laminated sheet as a whole, eventually leading to reliable design and successful forming process development of such materials. Finite element analyses of laminate sheet forming are presented. Effects of polymer core thickness and viscoelastic properties of the polymer core, as well as punching velocity, are also investigated.

  2. Investigation of corrosion-resistant LC200N steel by back scattering Mössbauer spectrometry

    NASA Astrophysics Data System (ADS)

    Pašteka, Lukáš; Miglierini, Marcel; Dekan, Július; Štefánik, Milan

    2016-10-01

    In this work we focus on characterization of LC200N steel by back-scattering Mössbauer spectrometry (MS). This geometry was used due to high sample thickness (0.5 mm). MS is a method suitable for determination of iron compounds and their properties in steels. We investigated samples with three different thermal treatments: non-hardened, hardened, and hardened with subsequent rapid quenching. Disk-shaped samples were cut off from original rods and polished from one side. The effect of surface treatment was investigated, too. Variations in microstructure imposed by different thermal and surface treatments were unveiled by Mössbauer parameters of backscattering spectra taken from both sides of the investigated samples. In this way, differences between the original as-cut and polished surfaces of the disks were unveiled.

  3. Investigations on fracture curves in strain and stress space for advanced high strength steel forming

    NASA Astrophysics Data System (ADS)

    Panich, S.; Drotleff, K.; Liewald, M.; Uthaisangsuk, V.

    2016-08-01

    Conventional forming limit curves (FLCs) are inappropriate for describing formability for advanced high strength (AHS) steel sheets, since such steel grades experience fracture without localized necking occurrence. The aim of this work was to develop a fracture curve (FC) for the AHS steel grade DP980. The FC was determined by means of the Nakajima stretch forming test and tensile tests of various sample geometries, by which shear fracture governed. An optical strain measurement system was used to capture strain histories of deformed samples up to failure. From these results, fracture strains were gathered and plotted in a strain space. Subsequently, the strain based curve was transformed to space between stress triaxiality and plastic strain. Hereby, effects of anisotropic yield function, namely, the Hill’48 model on obtained stress fracture loci were investigated. In order to verify applicability of the determined limit curves, a Mini-tunnel part was pressed and simulated. It was found that the stress based FC do predict failure of the DP980 steel sheet more accurately than the strain based F C.

  4. Investigation of carbon segregation during low temperature tempering in a medium carbon steel

    SciTech Connect

    Xiao, Y.; Li, W.; Zhao, H.S.; Lu, X.W.; Jin, X.J.

    2016-07-15

    Low temperature tempering is important in improving the mechanical properties of steels. In this study, the thermoelectric power method was employed to investigate carbon segregation during low temperature tempering ranging from 110 °C to 170 °C of a medium carbon alloyed steel, combined with micro-hardness, transmission electron microscopy and atom probe tomography. Evolution of carbon dissolution from martensite and segregation to grain boundaries/interfaces and dislocations were investigated for different tempering conditions. Carbon concentration variation was quantified from 0.33 wt.% in quenching sample to 0.15 wt.% after long time tempering. The kinetic of carbon diffusion during tempering process was discussed through Johnson-Mehl-Avrami equation. - Highlights: • The thermoelectric power (TEP) was employed to investigate the low temperature tempering of a medium carbon alloyed steel. • Evolution of carbon dissolution was investigated for different tempering conditions. • Carbon concentration variation was quantified from 0.33 wt.% in quenching sample to 0.15 wt.% after long time tempering.

  5. Experimental investigation of microbiologically influenced corrosion of selected steels in sugarcane juice environment.

    PubMed

    Wesley, Sunil Bala; Maurya, Devendra Prasad; Goyal, Hari Sharan; Negi, Sangeeta

    2013-12-01

    In the current study, ferritic stainless grades AISI 439 and AISI 444 were investigated as possible construction materials for machinery and equipment in the cane-sugar industry. Their performance in corrosive cane-sugar juice environment was compared with the presently used low carbon steel AISI 1010 and austenitic stainless steel AISI 304. The Tafel plot electrochemical technique was used to evaluate general corrosion performance. Microbiologically influenced corrosion (MIC) behaviour in sugarcane juice environment was studied. Four microbial colonies were isolated from the biofilms on the metal coupon surfaces on the basis of their different morphology. These were characterized as Brevibacillus parabrevis, Bacillus azotoformans, Paenibacillus lautus and Micrococcus sp. The results of SEM micrographs showed that AISI 439 and AISI 304 grades had suffered maximum localized corrosion. MIC investigations revealed that AISI 444 steel had the best corrosion resistance among the tested materials. However from the Tafel plots it was evident that AISI 1010 had the least corrosion resistance and AISI 439 the best corrosion resistance.

  6. Influence of hydrogen-oxidizing bacteria on the corrosion of low carbon steel: Local electrochemical investigations.

    PubMed

    Moreira, Rebeca; Schütz, Marta K; Libert, Marie; Tribollet, Bernard; Vivier, Vincent

    2014-06-01

    Low carbon steel has been considered a suitable material for component of the multi-barrier system employed on the geological disposal of high-level radioactive waste (HLW). A non negligible amount of dihydrogen (H2) is expected to be produced over the years within the geological repository due to the anoxic corrosion of metallic materials and also to the water radiolysis. The influence of the activity of hydrogen-oxidizing bacteria (HOB) and iron-reducing bacteria (IRB) on carbon steel corrosion is considered in this study because of the high availability of energetic nutriments (H2, iron oxides and hydroxides) produced in anoxic disposal conditions. Local electrochemical techniques were used for investigating the activity of IRB as a promoter of local corrosion in the presence of H2 as electron donor. A local consumption of H2 by the bacteria has been evidenced and impedance measurements indicate the formation of a thick layer of corrosion products.

  7. Spectroscopic investigation of plasma electrolytic borocarburizing on q235 low-carbon steel

    NASA Astrophysics Data System (ADS)

    Liu, Run; Wang, Bin; Wu, Jie; Xue, Wenbin; Jin, Xiaoyue; Du, Jiancheng; Hua, Ming

    2014-12-01

    A plasma electrolytic borocarburizing process (PEB/C) in borax electrolyte with glycerin additive was employed to fabricate a hardening layer on Q235 low-carbon steel. Optical emission spectroscopy (OES) was utilized to investigate the spectroscopy characteristics of plasma discharge around the steel during PEB/C process. Some plasma parameters were calculated in terms of OES. The electron temperature and electron concentration in plasma discharge zone is about 3000-12,000 K and 2 × 1022 m-3-1.4 × 1023 m-3. The atomic ionization degrees of iron, carbon and boron are 10-16-10-3, and 10-23-10-6, 10-19-10-4, respectively, which depend on discharge time. The surface morphology and cross-sectional microstructure of PEB/C hardening layer were observed, and the electrolyte decomposition and plasma discharge behaviors were discussed.

  8. Investigation of defect rate of lap laser welding of stainless steel railway vehicles car body

    NASA Astrophysics Data System (ADS)

    Wang, Hongxiao

    2015-02-01

    In order to resolve the disadvantages such as poor appearance quality, poor tightness, low efficiency of resistance spot welding of stainless steel rail vehicles, partial penetration lap laser welding process was investigated widely. But due to the limitation of processing technology, there will be local incomplete fusion in the lap laser welding seam. Defect rate is the ratio of the local incomplete fusion length to the weld seam length. The tensile shear strength under different defect rate and its effect on the car body static strength are not clear. It is necessary to find the biggest defect rate by numerical analysis of effects of different defect rates on the laser welding stainless steel rail vehicle body structure strength ,and tests of laser welding shear tensile strength.

  9. RBS, AES, EDX and ESCA investigation of heat treatment effects on stainless steel alloy 440C

    NASA Astrophysics Data System (ADS)

    Taylor, T.; Ila, D.; Cochrane, J. C.

    1994-03-01

    We have investigated the oxidation of stainless steel alloy 440C at various temperatures using Rutherford Backscattering Spectrometry (RBS), Auger Electron Spectroscopy (AES), Energy Dispersive X-ray Analysis (EDX) and Electron Spectroscopy for Chemical Analysis (ESCA). The chemical state of the various oxides formed at each temperature was measured by ESCA. The relative surface concentrations of Cr and Fe were measured using all four techniques. EDX data provided us with a standard for bulk concentrations of Cr and Fe. The results of RBS and AES were used to develop an empirical relationship between the {Cr}/{Fe} ratio and the heat treatment temperature. This empirical relationship can be used to determine the temperature at which a given component made of stainless steel alloy 440C, has been operating by measuring the {Cr}/{Fe} ratio at the surface.

  10. Experimental investigation on different patterned bolted/welded structural connection in steel and GFRP plates

    NASA Astrophysics Data System (ADS)

    Kanchidurai, S.; Vivek, P.

    2017-07-01

    The experimental investigation is explained different structural connection like various patterned single shear lap bolted connections and slot complete penetration welded connection. Totally 12 numbers of 300 x 50 x 4 mm steel connections made by lap joint as per IS800: 2007 provisions. The patterns are linear, diamond and staggered for the bolted and slot complete penetration welded connections, 4.6 grade bolt and tungsten electrode rods are used for structural slot complete penetration welded connection conforming to IS 800: 2007. And 6 numbers of 300 x 50 x 6mm Glass fibre reinforced polymer (GFRP) plate with bolted connection was casted, shear resistance capacity is considerably higher in the staggered pattern structural connections then the linear and diamond pattern connections. The connection which is made by GFRP, failure occurred in the plate itself and the shear resistance capacity is lowered 60% then the steel plate even though GFRP plate high resistivity against aggressive environment

  11. A Computational Investigation on Bending Deformation Behavior at Various Deflection Rates for Enhancement of Absorbable Energy in TRIP Steel

    NASA Astrophysics Data System (ADS)

    Pham, Hang Thi; Iwamoto, Takeshi

    2016-08-01

    Transformation-induced plasticity (TRIP) steel might have a high energy-absorption characteristic because it could possibly consume impact energy by not only plastic deformation but also strain-induced martensitic transformation (SIMT) during deformation. Therefore, TRIP steel is considered to be suitable for automotive structures from the viewpoint of safety. Bending deformation due to buckling is one of the major collapse modes of automotive structures. Thus, an investigation on the bending deformation behavior and energy-absorption characteristic in TRIP steel at high deformation rate is indispensable to clarify the mechanism of better performance. Some past studies have focused on the improvement of mechanical properties by means of SIMT; however, the mechanism through which the energy-absorption characteristic in steel can be improved is still unclear. In this study, the three-point bending deformation behavior of a beam specimen made of type-304 austenitic stainless steel, a kind of TRIP steel, is investigated at various deflection rates by experiments and finite-element simulations based on a constitutive model proposed by one of the authors. After confirming the validity of the computation, the rate-sensitivity of energy absorption from the viewpoint of hardening behavior is examined and the improvement of the energy-absorption characteristic in TRIP steel including its mechanism is discussed.

  12. An Investigation of the Role of Second Phase Particles in the Design of Ultra High Strength Steels of Improved Toughness

    DTIC Science & Technology

    1990-06-20

    examples in the literature. The only example in the literature of blunting to vertices from an initially sharp crack is the blunting of HY80 steel to three...AD-A226 056 AN INVESTIGATION OF THE ROLE OF SECOND PHASE PARTICLES IN THE DESIGN OF ULTRA HIGH STRENGTH STEELS OF IMPROVED TOUGHNESS FINAL REPORT W...THE ROLE OF SECOND PHASE PARTICLES IN THE DESIGN OF ULTRA HIGH STRENGTH STEELS OF IMPROVED TOUGHNESS FINAL REPORT W. M. Garrison, Jr. June 15, 1990 U.S

  13. Micromagnetic and Moessbauer spectroscopic investigation of strain-induced martensite in austenitic stainless steel

    SciTech Connect

    Meszaros, I.; Kaldor, M.; Hidasi, B.; Vertes, A.; Czako-Nagy, I.

    1996-08-01

    Strain-induced martensite in 18/8 austenitic stainless steel was studied. Magnetic measurements and Moessbauer spectroscopic investigations were performed to characterize the amount of {alpha}{prime}-martensite due to room-temperature plastic tensile loading. The effects of cold work and annealing heat treatment were explored using magnetic Barkhausen noise, saturation polarization, coercive force, hardness, and conversion electron Moessbauer spectroscopy. The suggested Barkhausen noise measurement technique proved to be a useful quantitative and nondestructive method for determining the ferromagnetic phase ratio of the studied alloy.

  14. An investigation of the {alpha}-{epsilon} phase transition in shock loaded EN3 mild steel

    SciTech Connect

    Millett, J. C. F.; Bourne, N. K.; Rosenberg, Z.

    1998-07-10

    The {alpha}-{epsilon} phase transition in a mild steel has been investigated using manganin stress gauges mounted in longitudinal orientation. The phase transformation has been located at 13.3{+-}0.3 GPa. Since the gauges have been mounted within the specimen, it has been possible to directly measure parameters of the phase change such as the transformation stress and the Hugoniot stress without the interference of releases that attend back-surface measurements. Strain gauges have been embedded alongside the stress gauges. In this orientation they are sensitive to lateral strain. Evidence has been collected that suggests the possibility of non-uniaxial strain behind the transformation front.

  15. Investigating Thermal Interactions in the Case of Laser Assisted Joining of PMMA Plastic and Steel

    NASA Astrophysics Data System (ADS)

    Bauernhuber, Andor; Markovits, Tamás

    Laser transmission joining of dissimilar materials is a novel and promising area of researches on joining technology. However, processes during laser assisted metal plastic (LAMP) joining are not completely explained yet. In the course of this study, the authors investigated the joining process of PMMA plastic and steel by means of laser, as a part of their research on dissimilar material joining. The characteristic process temperature was measured during the joining by different heating conditions, to describe thermal interactions between the polymer and the metal part, and to better understand the mechanism of joining.

  16. Experimental and analytical investigation of the seizure process in aluminum-silicon alloy/steel tribocontacts

    NASA Astrophysics Data System (ADS)

    He, Xiaozhou

    1998-12-01

    This research is an experimental and analytical investigation of the scuffing/seizure mechanism in Al-Si alloy/steel tribocontacts. An analytical model is developed based on analyses and experiments to predict scuffing/seizure failure in Al-Si alloy/steel tribocontacts, which can be applied to tribo-components in engines, refrigerators and air conditioners. The wear and scuffing/seizure experiments have been conducted through a block-on-ring tester for 339 and ESE-M2A137 Al-Si alloys under the dry and boundary lubrication conditions. The experimental research consists of: (a) wear debris generation and EDX analysis, (b) wear surface morphological analysis, (c) scuffing/seizure mechanism and process analysis, (d) scuffing/seizure PV curves under the dry contact and boundary lubrication, and (e) effects of several main factors on scuffing/seizure. The analytical research includes the following: (a) the investigation of the scuffing/seizure mechanisms in the Al-Si alloy/steel tribocontacts, (b) 3-D asperity contact pressures for longitudinal, transverse and isotropic surface roughness profiles, (c) 3-D surface asperity contact temperature rise due to the friction, (d) failure analyses of the various lubricating films, (e) analyses of the temperature dependence of surface tangential traction and shear strength in a surface layer of Al-Si alloy, (f) the scuffing/seizure failure analytical model under dry contact and boundary lubrication. The analytical model is based on the new hypothesis of three defense lines against scuffing/seizure failure: the adsorbed oil film, oxide film and the ratio of surface tangential traction with the shear strength in a surface layer. These two films together with a surface layer itself form three defense lines against scuffing/seizure. The surface tangential traction exceeds the bulk shear strength in a surface layer of Al-Si alloy is the necessary and sufficient condition for the scuffing/seizure occurrence. The analytical model has a

  17. An Investigation on Low-Temperature Thermochemical Treatments of Austenitic Stainless Steel in Fluidized Bed Furnace

    NASA Astrophysics Data System (ADS)

    Haruman, E.; Sun, Y.; Triwiyanto, A.; Manurung, Y. H. P.; Adesta, E. Y.

    2012-03-01

    In this study, the feasibility of using an industrial fluidized bed furnace to perform low-temperature thermochemical treatments of austenitic stainless steels has been studied, with the aim to produce expanded austenite layers with combined wear and corrosion resistance, similar to those achievable by plasma and gaseous processes. Several low-temperature thermochemical treatments were studied, including nitriding, carburizing, combined nitriding-carburizing (hybrid treatment), and sequential carburizing and nitriding. The results demonstrate that it is feasible to produce expanded austenite layers on the investigated austenitic stainless steel by the fluidized bed heat treatment technique, thus widening the application window for the novel low-temperature processes. The results also demonstrate that the fluidized bed furnace is the most effective for performing the hybrid treatment, which involves the simultaneous incorporation of nitrogen and carbon together into the surface region of the component in nitrogen- and carbon-containing atmospheres. Such hybrid treatment produces a thicker and harder layer than the other three processes investigated.

  18. Experimental Investigations And Numerical Modelling of 210CR12 Steel in Semi-Solid State

    SciTech Connect

    Maciol, Piotr; Jakubowicz, Aleksandra; Wladislaw, Stanislaw; Zalecki, Wladyslaw; Kuziak, Roman

    2011-05-04

    Experimental investigation, including hot compression and simple closed die filling was performed. Temperature range of tests was between 1225 deg. C and 1320 deg. C. Temperature selection was adequate with liquid fraction between 20 and 60%, which is typical for thixoforming processes. In the die filling test, steel dies with ceramic layer was used (highly refractory air-setting mortar JM 3300 manufactured by Thermal Ceramics). Experiments were carried out on the Gleeble 3800 physical simulator with MCU unit. In the paper, methodology of experimental investigation is described. Dependency of forming forces on temperature and forming velocities is analysed. Obtained results are discussed. The second part of the paper concerns numerical modelling of semi-solid forming. Numerical models for both sets of test were developed. Structural and Computational Fluid Dynamics models are compared. Initial works in microstructural modelling of 210CR12 steel behaviour are described. Lattice Boltzman Method model for thixotropic flows is introduced. Microscale and macroscale models were integrated into multiscale simulation of semi-solid forming. Some fundamental issues related to multiscale modelling of thixoforming are discussed.

  19. Deformation mechanisms of a 20Mn TWIP steel investigated by in situ neutron diffraction and TEM

    SciTech Connect

    Shen, Yongfeng; Wang, Y. D.; Liu, Xiaopeng; Sun, Xin; Peng, R. Lin; Zhang, S. Y.; Zuo, Liang; Liaw, Peter K.

    2013-07-25

    The deformation mechanisms and associated microstructure changes during tensile loading of an annealed twinning-induced plasticity (TWIP) steel with the chemical composition of Fe–20Mn–3Si–3Al–0.045C (wt.%) were systematically investigated using in situ time-of-flight (TOF) neutron diffraction in combination with postmortem transmission electron microscopy (TEM). The initial microstructure of the investigated alloy consists of equiaxed austenitic grains with the initial α´-phase of ~7% in volume. In addition to dislocation slip, twinning and two kinds of martensitic transformations from the austenite to α´- and epsilon martensites were observed as the main deformation modes during the tensile deformation. In situ neutron diffraction provides a powerful tool to establish the deformation mode map for elucidating the role of different deformation modes in different strain regions. The critical stress is 520 MPa for the martensitic transformation from the austenite to α´-martensite, whereas a higher stress (>600 MPa) is required for actuating the deformation twin and/or the martensitic transformation from -martensite. Both epsilon- and α´-martensites act as the hard phases whereas mechanical twinning contributes to both strength and ductility of the studied steel. TEM observations confirmed that the twinning process was facilitated by the parent grains orientated with <111> or <110> parallel to the loading direction. The nucleation and growth of twins are attributed to the pole and self-generation formation mechanisms, as well as the stair-rod cross-slip mechanism.

  20. Investigation of microstructural alterations in M50 and 52100 steel using nanoindentation

    NASA Astrophysics Data System (ADS)

    Paulson, Kristin R.

    Bearing steels are used in rolling elements and are designed to withstand heavy loads for an extended period of time. At the end of life, microstructural alterations within the material have been observed and are linked to failure. In this study, a three ball-on-rod fatigue tester was used to test M50 and 52100 steel cylindrical rods at differing loads of 4.0 GPa, 4.5 GPa, and 5.0 GPa and in lubricated and unlubricated conditions to 108 cycles in an attempt to produce microstructural alterations. Microstructural alterations characterized as butterflies were observed and investigated further in two M50 samples that were tested at 4.5 GPa to 10 8 cycles in the lubricated and unlubricated condition. Microstructural alterations characterized as dark etching regions (DER), and white etching bands (WEBs) were not observed. Additionally, hardness was investigated cross sectionally as a function of depth and location within the wear track produced by the fatigue test. No conclusive evidence was derived from the hardness measurements as a function of depth in relation to the formation of microstructural alterations or the stress experienced subsurface within the material. Hardness measurements performed specifically within a butterfly wing, however, returned hardness values significantly higher than the matrix hardness values.

  1. Experimental Investigations And Numerical Modelling of 210CR12 Steel in Semi-Solid State

    NASA Astrophysics Data System (ADS)

    Macioł, Piotr; Zalecki, Władysław; Kuziak, Roman; Jakubowicz, Aleksandra; Weglarczyk, Stanisław

    2011-05-01

    Experimental investigation, including hot compression and simple closed die filling was performed. Temperature range of tests was between 1225 °C and 1320 °C. Temperature selection was adequate with liquid fraction between 20 and 60%, which is typical for thixoforming processes. In the die filling test, steel dies with ceramic layer was used (highly refractory air-setting mortar JM 3300 manufactured by Thermal Ceramics). Experiments were carried out on the Gleeble 3800 physical simulator with MCU unit. In the paper, methodology of experimental investigation is described. Dependency of forming forces on temperature and forming velocities is analysed. Obtained results are discussed. The second part of the paper concerns numerical modelling of semi-solid forming. Numerical models for both sets of test were developed. Structural and Computational Fluid Dynamics models are compared. Initial works in microstructural modelling of 210CR12 steel behaviour are described. Lattice Boltzman Method model for thixotropic flows is introduced. Microscale and macroscale models were integrated into multiscale simulation of semi-solid forming. Some fundamental issues related to multiscale modelling of thixoforming are discussed.

  2. 78 FR 44532 - Steel Threaded Rod From India: Initiation of Countervailing Duty Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... International Trade Administration Steel Threaded Rod From India: Initiation of Countervailing Duty... (``CVD'') petition concerning imports of steel threaded rod from India, filed in proper form by All...., (collectively hereinafter ``Petitioners'').\\1\\ Petitioners are domestic producers of steel threaded rod. On...

  3. 77 FR 60673 - Drawn Stainless Steel Sinks From the People's Republic of China: Antidumping Duty Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... International Trade Administration Drawn Stainless Steel Sinks From the People's Republic of China: Antidumping...'') preliminarily determines that drawn stainless steel sinks (``drawn sinks'') from the People's Republic of China... unfinished, regardless of type of finish, gauge, or grade of stainless steel. Mounting clips,...

  4. 78 FR 60831 - Steel Concrete Reinforcing Bar From Turkey: Initiation of Countervailing Duty Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... International Trade Administration Steel Concrete Reinforcing Bar From Turkey: Initiation of Countervailing Duty... (``CVD'') petition \\1\\ concerning imports of steel concrete reinforcing bar (``rebar'') from the Republic... Countervailing Duties on Imports of Steel Concrete Reinforcing Bar from the Republic of Turkey, dated September...

  5. 78 FR 60827 - Steel Concrete Reinforcing Bar From Mexico and Turkey: Initiation of Antidumping Duty Investigations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... International Trade Administration Steel Concrete Reinforcing Bar From Mexico and Turkey: Initiation of... imports of steel concrete reinforcing bar (``rebar'') from Mexico and Turkey filed in proper form on... Duties on Steel Concrete Reinforcing Bar from Mexico and Turkey and the Imposition of...

  6. Experimental Investigation of Tensile Test on Connection of Cold-formed Cut-curved Steel Section

    NASA Astrophysics Data System (ADS)

    Sani, Mohd Syahrul Hisyam Mohd; Muftah, Fadhluhartini; Rahman, Nurul Farraheeda Abdul; Fakri Muda, Mohd

    2017-08-01

    Cold-formed steel (CFS) is widely used as structural and non-structural components such as roof trusses and purlin. A CFS channel section with double intermediate web stiffener and lipped is chosen based on the broader usage in roof truss construction. CFS section is cut to form cold-formed pre-cut-curved steel section and lastly strengthened by several types of method or likely known as connection to establish the cold-formed cut-curved steel (CFCCS) section. CFCCS is proposed to be used as a top chord section in the roof truss system. The CFCCS is to resist the buckling phenomena of the roof truss structure and reduced the compression effect on the top chord. The tensile test connection of CFCCS section, especially at the flange element with eight types of connection by welding, plate with self-drilling screw and combination is investigated. The flange element is the weakest part that must be solved first other than the web element because they are being cut totally, 100% of their length for curving process. The testing is done using a universal testing machine for a tensile load. From the experiment, specimen with full welding has shown as a good result with an ultimate load of 13.37 kN and reported having 35.41% when compared with normal specimen without any of connection methods. Furthermore, the experimental result is distinguished by using Eurocode 3. The failure of a full welding specimen is due to breaking at the welding location. Additionally, all specimens with either full weld or spot weld or combination failed due to breaking on weld connection, but specimen with flange plate and self-drilling screw failed due to tilting and bearing. Finally, the full welding specimen is chosen as a good connection to perform the strengthening method of CFCCS section.

  7. Investigation of the stress corrosion cracking of duplex stainless steel weldments in sour conditions

    SciTech Connect

    Schofield, M.J.; Bradshaw, R.; Cottis, R.A.

    1995-10-01

    Duplex stainless steels are increasingly widely used in the oil and gas production industry for a variety of applications. The stress corrosion cracking (SCC) behavior of wrought material is reasonably well understood, and limits of use are placed upon these alloys in NACE MR0175, for sour service. However, the SCC behavior of weldments is less well understood, and this has limited the use of welded material in H{sub 2}S-containing conditions. The SCC resistance of duplex stainless steels is influenced by their microstructure as well as their chemical composition and the objective of the research reported in this paper is to investigate the SCC behavior of welded 22%Cr and 25%Cr alloys in a simulated oilfield environment. Mechanized orbital TIG was used to butt weld 168mm outside diameter tubes. The shielding gas contained nitrogen additions of up to 10% (in the case of UNS S32760) and 7% (in the case of UNS S31803). Slow strain rate testing (SSRT) was conducted on cross-weld specimens in sodium chloride solutions overpressured with varying partial pressures of H{sub 2}S and CO{sub 2}. The SSRT results, in terms of ductility parameters and secondary cracking, are correlated with fractography and metallurgical examination of crack morphology in order to establish the effects of the welding process and the nitrogen content of the shielding gas. It was found that the nitrogen uptake from the shielding gas has a detrimental effect on SCC resistance of duplex stainless steel weldments. While this effect is only modes, it is in direct contrast to the beneficial effect it has on pitting corrosion resistance.

  8. Investigation on Nonmetallic Inclusions in Ultra-Low-Oxygen Special Steels

    NASA Astrophysics Data System (ADS)

    Li, Jin Zhu; Jiang, Min; He, Xiao-Fei; Sun, Wei; Wang, Xin-Hua

    2016-08-01

    Investigation was carried out on inclusions in ultra-low-oxygen special steel by taking systematic samplings not only from secondary refining but also from continuous casting. It was found that RH degassing had a much stronger ability than LF refining in removing inclusions. Total oxygen (TO) can be further reduced from 0.0013 to 0.0015 mass pct to about 0.00047 mass pct without too much difficulty by elongating RH degassing time to 33 minute. Inclusions larger than 5 μm were decreased from 1.49 to 0.08 N/mm2 with a removal ratio of about 94 pct. During secondary refining, inclusions experienced continuous evolution from Al2O3 to the MgO-Al2O3, CaO-MgO-Al2O3, and CaO-Al2O3 system due to complex reactions among slag, steel, and refractory materials. Because of more efficient removal of solid inclusions, especially those large ones during RH treatment, thorough modification of solid inclusions into liquid CaO-MgO-Al2O3 can be achieved. Reoxidation during casting resulted in an obvious rise in Al2O3 content in inclusions, which offset the efforts made during secondary refining. Liquid CaO-Al2O3 systems after RH were changed to solid CaO-Al2O3, MgO-Al2O3, or CaO-MgO-Al2O3 again. Large inclusions with sizes approaching several hundred micron were frequently observed in casting bloom by a vast area of scanning under an automatic scanning electron microscope despite very low TO of about 0.00059 mass pct. A total of 78 pct of them were cluster-shaped CaO-MgO-Al2O3 solid inclusions with sizes as large as 200-330 μm. Most clusters over 100 μm were constituted by smaller particles with similar chemical compositions to other small singular inclusions in steel, which indicated that they were formed due to the aggregations of small inclusions during casting. Moreover, the location of them indicated a close relationship to the solidification microstructure of steel, which has not been covered before. It was impressively found that larger inclusions were mainly in the column

  9. Investigation about the Chrome Steel Wire Arc Spray Process and the Resulting Coating Properties

    NASA Astrophysics Data System (ADS)

    Wilden, J.; Bergmann, J. P.; Jahn, S.; Knapp, S.; van Rodijnen, F.; Fischer, G.

    2007-12-01

    Nowadays, wire-arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications. However, detailed studies are the basis for further process optimization. In order to optimize the process parameters and to evaluate the effects of the spray parameters DoE-based experiments had been carried out with high-speed camera shoots. In this article, the effects of spray current, voltage, and atomizing gas pressure on the particle jet properties, mean particle velocity and mean particle temperature and plume width on X46Cr13 wire are presented using an online process monitoring device. Moreover, the properties of the coatings concerning the morphology, composition and phase formation were subject of the investigations using SEM, EDX, and XRD-analysis. These deep investigations allow a defined verification of the influence of process parameters on spray plume and coating properties and are the basis for further process optimization.

  10. Investigations of Localized Corrosion of Stainless Steel after Exposure to Supercritical CO2

    SciTech Connect

    M. Ziomek-Moroz; W. O’Connor; S. Bullard

    2012-03-11

    Severe localized corrosion of a 316 stainless steel autoclave occurred during investigating Type H Portland cement stability in 0.16 M CaCl{sub 2} + 0.02 M MgCl{sub 2} + 0.82 M NaCl brine in contact with supercritical CO{sub 2} containing 4% O{sub 2}. The system operated at 85 C and pressure of 29 MPa. However, no corrosion was observed in the same type of autoclave being exposed to the same environment, containing Type H Portland cement cylindrical samples, also operating at pressure of 29 MPa but at 50 C. The operation time for the 85 C autoclave was 53 days (1272 hours) while that for the 50 C autoclave was 66 days (1584 hours). Debris were collected from the base of both autoclaves and analyzed by X-ray diffraction (XRD). Corrosion products were only found in the debris from the 85 C autoclave. The cement samples were analyzed before and after the exposure by X-ray florescence (XRF) methods. Optical microscopy was used to estimate an extent of the 316 stainless steel corrosion degradation.

  11. Investigation of Hot Deformation Behavior of Duplex Stainless Steel Grade 2507

    NASA Astrophysics Data System (ADS)

    Kingklang, Saranya; Uthaisangsuk, Vitoon

    2017-01-01

    Recently, duplex stainless steels (DSSs) are being increasingly employed in chemical, petro-chemical, nuclear, and energy industries due to the excellent combination of high strength and corrosion resistance. Better understanding of deformation behavior and microstructure evolution of the material under hot working process is significant for achieving desired mechanical properties. In this work, plastic flow curves and microstructure development of the DSS grade 2507 were investigated. Cylindrical specimens were subjected to hot compression tests for different elevated temperatures and strain rates by a deformation dilatometer. It was found that stress-strain responses of the examined steel strongly depended on the forming rate and temperature. The flow stresses increased with higher strain rates and lower temperatures. Subsequently, predictions of the obtained stress-strain curves were done according to the Zener-Hollomon equation. Determination of material parameters for the constitutive model was presented. It was shown that the calculated flow curves agreed well with the experimental results. Additionally, metallographic examinations of hot compressed samples were performed by optical microscope using color tint etching. Area based phase fractions of the existing phases were determined for each forming condition. Hardness of the specimens was measured and discussed with the resulted microstructures. The proposed flow stress model can be used to design and optimize manufacturing process at elevated temperatures for the DSS.

  12. Investigation of Parent Austenite Grains from Martensite Structure Using EBSD in a Wear Resistant Steel

    PubMed Central

    Gyhlesten Back, Jessica; Engberg, Göran

    2017-01-01

    Crystallographic reconstruction of parent austenite grain boundaries from the martensitic microstructure in a wear resistant steel was carried out using electron backscattered diffraction (EBSD). The present study mainly aims to investigate the parent austenite grains from the martensitic structure in an as-rolled (reference) steel sample and samples obtained by quenching at different cooling rates with corresponding dilatometry. Subsequently, this study is to correlate the nearest cooling rate by the dilatometer which yields a similar orientation relationship and substructure as the reference sample. The Kurdjumov-Sachs orientation relationship was used to reconstruct the parent austenite grain boundaries from the martensite boundaries in both reference and dilatometric samples using EBSD crystallographic data. The parent austenite grain boundaries were successfully evaluated from the EBSD data and the corresponding grain sizes were measured. The parent austenite grain boundaries of the reference sample match the sample quenched at 100 °C/s (CR100). Also the martensite substructures and crystallographic textures are similar in these two samples. The results from hardness measurements show that the reference sample exhibits higher hardness than the CR100 sample due to the presence of carbides in the reference sample. PMID:28772813

  13. Investigation of Parent Austenite Grains from Martensite Structure Using EBSD in a Wear Resistant Steel.

    PubMed

    Gyhlesten Back, Jessica; Engberg, Göran

    2017-04-26

    Crystallographic reconstruction of parent austenite grain boundaries from the martensitic microstructure in a wear resistant steel was carried out using electron backscattered diffraction (EBSD). The present study mainly aims to investigate the parent austenite grains from the martensitic structure in an as-rolled (reference) steel sample and samples obtained by quenching at different cooling rates with corresponding dilatometry. Subsequently, this study is to correlate the nearest cooling rate by the dilatometer which yields a similar orientation relationship and substructure as the reference sample. The Kurdjumov-Sachs orientation relationship was used to reconstruct the parent austenite grain boundaries from the martensite boundaries in both reference and dilatometric samples using EBSD crystallographic data. The parent austenite grain boundaries were successfully evaluated from the EBSD data and the corresponding grain sizes were measured. The parent austenite grain boundaries of the reference sample match the sample quenched at 100 °C/s (CR100). Also the martensite substructures and crystallographic textures are similar in these two samples. The results from hardness measurements show that the reference sample exhibits higher hardness than the CR100 sample due to the presence of carbides in the reference sample.

  14. Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale.

    PubMed

    Hossain, R; Pahlevani, F; Quadir, M Z; Sahajwalla, V

    2016-10-11

    Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels' performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano scale of the compressive stability of retained austenite in high carbon martensitic steel. Using a combination of standard compression testing, X-ray diffraction, optical microstructure, electron backscattering diffraction imaging, electron probe micro-analysis, nano-indentation and micro-indentation measurements, we determined the mechanical stability of retained austenite and martensite in high carbon steel under compressive stress and identified the phase transformation mechanism, from the macro to the nano level. We found at the early stage of plastic deformation hexagonal close-packed (HCP) martensite formation dominates, while higher compression loads trigger body-centred tetragonal (BCT) martensite formation. The combination of this phase transformation and strain hardening led to an increase in the hardness of high carbon steel of around 30%. This comprehensive characterisation of stress induced phase transformation could enable the precise control of the microstructures of high carbon martensitic steels, and hence their properties.

  15. An investigation of rolling-sliding contact fatigue damage of carburized gear steels

    NASA Astrophysics Data System (ADS)

    Kramer, Patrick C.

    The goal of this study was to evaluate the differences in RSCF performance between vacuum and gas carburized steels as well as to investigate the evolution of damage (wear and microstructure changes) leading to pitting. Vacuum and gas carburizing was performed on two gear steels (4120 and 4320) at 1010°C. The carburized specimens were tested in the as-carburized condition using a RSCF machine designed and built at the Colorado School of Mines. The tests were conducted at 3.2 GPa nominal Hertzian contact stress, based on pure rolling, 100°C, and using a negative twenty percent slide ratio. Tests were conducted to pitting failure for each condition for a comparison of the average fatigue lives. Pure rolling tests were also conducted, and were suspended at the same number of cycles as the average RSCF life for a comparison of fatigue damage developed by RCF and RSCF. Incremental tests were suspended at 1,000, 10,000, 100,000, and 200,000 cycles for the vacuum carburized steels to evaluate the wear and damage developed during the initial cycles of RSCF testing and to relate the wear and damage to pitting resistance. Incremental damage was not investigated for gas carburizing due to the limited number of available specimens. The vacuum carburized samples showed a decreased pitting fatigue resistance over the gas carburized samples, possibly due to the presence of bainite in the vacuum carburized cases. Pitting was observed to initiate from surface micropitting and microcracking. A microstructural change induced by contact fatigue, butterflies, was shown to contribute to micropitting and microcracking. Incremental testing revealed that the formation of a microcrack preceded and was necessary for the formation of the butterfly features, and that the butterfly features developed between 10,000 and 100,000 cycles. The orientation and depth of butterfly formation was shown to be dependent upon the application of traction stresses from sliding. RSCF butterflies formed

  16. Corrosion fatigue behavior of low alloy steels under simulated BWR coolant conditions

    NASA Astrophysics Data System (ADS)

    Huang, J. Y.; Young, M. C.; Jeng, S. L.; Yeh, J. J.; Huang, J. S.; Kuo, R. C.

    2010-10-01

    The corrosion fatigue crack growth behavior of A533 and A508 low alloy steels under simulated boiling water reactor (BWR) coolant conditions was studied. Corrosion fatigue crack growth rates of A533B3 and A508 cl. 3 steels were significantly affected by the steel sulfur content, loading frequency and dissolved oxygen content of water environments. The data points outside the bound of Eason's model could be attributed to the low frequency, higher steel sulfur content and high dissolved oxygen in water environments. The sulfur dissolved in the water environment from the higher-sulfur steels was sufficiently concentrated to acidify the crack tip chemistry even in the hydrogen water chemistry (HWC). Therefore, nitrogenated or HWC water showed little or no beneficiary effect on the high-sulfur steels. For the steel specimens of the same sulfur level, their corrosion fatigue crack growth rates were comparable in different orientations, which could be related to the exposure of fresh sulfides to the water environment. The percentages of sulfides per unit area, by quantitative metallography, were comparable for the steel specimens of both orientations. When the steel sulfur content was decreased to a critical sulfur content 0.005 wt.%, the crack growth rates decreased remarkably.

  17. Investigation on the buckling of steel piers of elevated expressway due to the Great Hanshin Earthquake

    SciTech Connect

    Fujita, Katsuhisa; Nakamura, Kazuhiro; Ito, Tomohiro; Iwamoto, Yoichi

    1996-12-01

    In the Great Hanshin Earthquake which occurred in January 1995, extremely serious damages to the elevated expressways were found. Some of those piers are made of steel and many of them buckled and revealed plastic deformations. One of them revealed the circumferentially uniform outward bulge at the middle portion in the axial direction, though the buckling of a long circular cylinder will occur at it`s bottom end accompanied by more complicated deformation patterns typical to the bending buckling. In this study, simple reduced scale models of the pier were fabricated and the dynamic and static buckling tests were performed. The effect of the girder weight or vertical excitation on the buckling phenomena were investigated. In addition to the tests, static buckling analysis using FEM was also performed in order to clarify the causes for this specified buckling phenomena.

  18. Use of XPS to investigate surface problems in ULC deep drawing steels

    NASA Astrophysics Data System (ADS)

    Lamberigts, Marcel; Servais, Jean-Pierre

    1999-04-01

    During continuous annealing prior to hot dip galvanising, the surface of ULC ( Ultra Low Carbon) deep drawing steels undergoes a range of chemical modifications that can affect interface reactions, thus influencing the quality of the metallic protective coating and the product's final user's properties. These phenomena were investigated by XPS, in a high-resolution, fully automatic spectrometer coupled with a tight preparation chamber, where the treatment can be simulated very faithfully, in terms of both heat cycle and protective atmosphere. Under vacuum, the equilibrium (Gibbs) surface segregation of alloying — or tramp — elements such as P, Sn, Sb, As, S and C is clearly the predominant phenomenon. Selective oxidation grows much more significant when annealing is performed under a water vapour containing N 2-5%H 2 protective atmosphere. It involves highly oxidisable elements such as Al, Mn and Si. Though much less intense than under vacuum, Gibbs segregation however remains present, in direct competition with selective oxidation.

  19. Microstructural investigations on Russian reactor pressure vessel steels by small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Ulbricht, A.; Boehmert, J.; Strunz, P.; Dewhurst, C.; Mathon, M.-H.

    The effect of radiation embrittlement has a high safety significance for Russian VVER reactor pressure vessel steels. Heats of base and weld metals of the as-received state, irradiated state and post-irradiation annealed state were investigated using small-angle neutron scattering (SANS) to obtain insight about the microstructural features caused by fast neutron irradiation. The SANS intensities increase in the momentum transfer range between 0.8 and 3 nm-1 for all the material compositions in the irradiated state. The size distribution function of the irradiation-induced defect clusters has a pronounced maximum at 1 nm in radius. Their content varies between 0.1 and 0.7 vol.% dependent on material composition and increases with the neutron fluence. The comparison of nuclear and magnetic scattering indicates that the defects differ in their composition. Thermal annealing reduces the volume fraction of irradiation defect clusters.

  20. Investigation on the Enhanced Oxidation of Ferritic/Martensitic Steel P92 in Pure Steam.

    PubMed

    Yuan, Juntao; Wu, Ximao; Wang, Wen; Zhu, Shenglong; Wang, Fuhui

    2014-04-03

    Oxidation of ferritic/martensitic steel P92 was investigated in pure oxygen and in pure steam at 600-800 °C by thermogravimetric analysis (TGA), optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results showed that the oxidation of P92 was significantly enhanced and multilayer scale with an outer iron oxides layer formed in pure steam. At 700 °C, the gas switch markedly influenced the scaling kinetics and scale microstructure. It was supposed that the higher affinity of iron to steam would be attributed to the enhanced oxidation of P92 in pure steam, and the much easier transport of hydroxyl would account for the significant difference induced by gas switch.

  1. Investigation on the Enhanced Oxidation of Ferritic/Martensitic Steel P92 in Pure Steam

    PubMed Central

    Yuan, Juntao; Wu, Ximao; Wang, Wen; Zhu, Shenglong; Wang, Fuhui

    2014-01-01

    Oxidation of ferritic/martensitic steel P92 was investigated in pure oxygen and in pure steam at 600–800 °C by thermogravimetric analysis (TGA), optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results showed that the oxidation of P92 was significantly enhanced and multilayer scale with an outer iron oxides layer formed in pure steam. At 700 °C, the gas switch markedly influenced the scaling kinetics and scale microstructure. It was supposed that the higher affinity of iron to steam would be attributed to the enhanced oxidation of P92 in pure steam, and the much easier transport of hydroxyl would account for the significant difference induced by gas switch. PMID:28788592

  2. Helium-Implantation-Induced Damage in NHS Steel Investigated by Slow-Positron Annihilation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Yuan-Fei; Shen, Tie-Long; Gao, Xing; Gao, Ning; Yao, Cun-Feng; Sun, Jian-Rong; Wei, Kong-Fang; Li, Bing-Sheng; Zhang, Peng; Cao, Xing-Zhong; Zhu, Ya-Bin; Pang, Li-Long; Cui, Ming-Huan; Chang, Hai-Long; Wang, Ji; Zhu, Hui-Ping; Wang, Dong; Song, Peng; Sheng, Yan-Bin; Zhang, Hong-Peng; Hu, Bi-Tao; Wang, Zhi-Guang

    2014-03-01

    Evolutions of defects and helium contained defects produced by atomic displacement and helium deposition with helium implantation at different temperatures in novel high silicon (NHS) steel are investigated by a slow positron beam. Differences of the defect information among samples implanted by helium to a fluence of 1 × 1017 ions/cm2 at room temperature, 300°C, 450°C and 750°C are discussed. It is found that the mobility of vacancies and vacancy clusters, a recombination of vacancy-type defects and the formation of the He-V complex lead to the occurrence of these differences. At high temperature irradiations, a change of the diffusion mechanism of He atoms/He bubbles might be one of the reasons for the change of the S-parameter.

  3. Direct Metal Deposition of H13 Tool Steel on Copper Alloy Substrate: Parametric Investigation

    NASA Astrophysics Data System (ADS)

    Imran, M. Khalid; Masood, S. H.; Brandt, Milan

    2015-12-01

    Over the past decade, researchers have demonstrated interest in tribology and prototyping by the laser aided material deposition process. Laser aided direct metal deposition (DMD) enables the formation of a uniform clad by melting the powder to form desired component from metal powder materials. In this research H13 tool steel has been used to clad on a copper alloy substrate using DMD. The effects of laser parameters on the quality of DMD deposited clad have been investigated and acceptable processing parameters have been determined largely through trial-and-error approaches. The relationships between DMD process parameters and the product characteristics such as porosity, micro-cracks and microhardness have been analysed using scanning electron microscope (SEM), image analysis software (ImageJ) and microhardness tester. It has been found that DMD parameters such as laser power, powder mass flow rate, feed rate and focus size have an important role in clad quality and crack formation.

  4. Experimental research to investigate the performance of bio coolant when turning of mild carbon steel

    NASA Astrophysics Data System (ADS)

    Agus Susanto, Tri; Nur, Rusdi

    2017-04-01

    Some literatures have been reported that the using bio coolant show better lubricating and cooling performances and reduce the occupational health risks associated with petroleum-oil-based coolant since they have lower toxicity. This paper investigates the effect the cutting conditions on the surface roughness through turning of mild carbon steel using dry, coolant and bio coolant. Measurement of surface roughness was conducted and then compared with the change of the cutting conditions. The relationship between surface roughness and cutting conditions was created in a curve for different of the cutting speed and coolant. The results indicate that the surface roughness was reduced when the speed of cutting is set to the highest level for all of coolant conditions (dry, coolant, and bio coolant) and constant of DOC and feed. The surface roughness had better performance using bio coolant than coolant conventional (mineral fluid).

  5. Electrochemical and passivation behavior investigation of ferritic stainless steel in simulated concrete pore media.

    PubMed

    Luo, Hong; Su, Huaizhi; Dong, Chaofang; Xiao, Kui; Li, Xiaogang

    2015-12-01

    The applications of stainless steel are one of the most reliable solutions in concrete structures to reduce chloride-induced corrosion problems and increase the structures service life, however, due to high prices of nickel, especially in many civil engineering projects, the austenitic stainless steel is replaced by the ferritic stainless steels. Compared with austenite stainless steel, the ferritic stainless steel is known to be extremely resistant of stress corrosion cracking and other properties. The good corrosion resistance of the stainless steel is due to the formation of passive film. While, there is little literature about the electrochemical and passive behavior of ferritic stainless steel in the concrete environments. So, here, we present the several corrosion testing methods, such as the potentiodynamic measurements, EIS and Mott-Schottky approach, and the surface analysis methods like XPS and AES to display the passivation behavior of 430 ferritic stainless steel in alkaline solution with the presence of chloride ions. These research results illustrated a simple and facile approach for studying the electrochemical and passivation behavior of stainless steel in the concrete pore environments.

  6. Electrochemical and passivation behavior investigation of ferritic stainless steel in simulated concrete pore media

    PubMed Central

    Luo, Hong; Su, Huaizhi; Dong, Chaofang; Xiao, Kui; Li, Xiaogang

    2015-01-01

    The applications of stainless steel are one of the most reliable solutions in concrete structures to reduce chloride-induced corrosion problems and increase the structures service life, however, due to high prices of nickel, especially in many civil engineering projects, the austenitic stainless steel is replaced by the ferritic stainless steels. Compared with austenite stainless steel, the ferritic stainless steel is known to be extremely resistant of stress corrosion cracking and other properties. The good corrosion resistance of the stainless steel is due to the formation of passive film. While, there is little literature about the electrochemical and passive behavior of ferritic stainless steel in the concrete environments. So, here, we present the several corrosion testing methods, such as the potentiodynamic measurements, EIS and Mott–Schottky approach, and the surface analysis methods like XPS and AES to display the passivation behavior of 430 ferritic stainless steel in alkaline solution with the presence of chloride ions. These research results illustrated a simple and facile approach for studying the electrochemical and passivation behavior of stainless steel in the concrete pore environments. PMID:26501086

  7. A predictive model for corrosion fatigue crack growth rates in RPV steels exposed to PWR environments

    SciTech Connect

    Atkinson, J.D.; Chen, Z.; Yu, J.

    1995-12-31

    Corrosion fatigue crack propagation rates have been measured in A533B Class 1 plate in stagnant PWR primary water for a range of steel sulphur contents, temperature and corrosion potential values. Parametric descriptions of the data collected under constant rig conditions give good correlations for each variable and are consistent with a crack tip environment controlled process related to sulphur chemistry. A modified crack velocity equation is proposed to include temperature, sulphur content, polarization potential, frequency and {Delta}K values and it is shown how the predictions compare with the proposed ASME XI revision. Critical fatigue situations are identified for 0.003% and 0.019% sulphur steels typical of modern and old plant. The use of the equation in assessing the synergistic effect of variables is discussed.

  8. Micro-mechanical investigation for effects of helium on grain boundary fracture of austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Miura, Terumitsu; Fujii, Katsuhiko; Fukuya, Koji

    2015-02-01

    Effects of helium (He) on grain boundary (GB) fracture of austenitic stainless steel were investigated by micro-tensile tests. Micro-bicrystal tensile specimens were fabricated for non-coincidence site lattice boundaries of He ion-irradiated 316 stainless steel by focused ion beam (FIB) micro-processing. Micro-tensile tests were conducted in a vacuum at room temperature in the FIB system. Specimens containing more than 2 at.% He fractured at GBs. The criteria for brittle fracture occurrence on GBs were: (1) He concentrations higher than 2 at.%; (2) formation of He bubbles on the GBs with less than a 5 nm spacing; and (3) matrix hardening to more than 4.6 GPa (nano-indentation hardness). The fracture stress of GB brittle fracture was lower for a specimen with higher He concentration while the size and areal density of the GB He bubbles were the same. The specimens that contained 10 at.% He and had been annealed at 923 K after irradiation fractured at the GB nominally in a brittle manner; however the inter-bubble matrix at the GB experienced ductile fracture. The annealing caused He bubbles to grow but decreased the areal density so that the spacing of the GB He bubbles widened and the hardness decreased, therefore the fracture mode changed from brittle to ductile. The findings revealed that He promotes GB fracture by weakening the GB strength and hardening the matrix due to the formation of He bubbles both on GBs and in the matrix. In addition, the findings suggested that GB segregated He atoms may have a role in GB fracture.

  9. Preliminary Investigation of Keyhole Phenomena during Single Layer Fabrication in Laser Additive Manufacturing of Stainless Steel

    NASA Astrophysics Data System (ADS)

    Matilainen, Ville-Pekka; Piili, Heidi; Salminen, Antti; Nyrhilä, Olli

    Laser additive manufacturing (LAM) is a fabrication technology that enables production of complex parts from metallic materials with mechanical properties comparable to conventionally manufactured parts. In the LAM process, parts are manufactured by melting metallic powder layer-by-layer with a laser beam. This manufacturing technology is nowadays called powder bed fusion (PBF) according to the ASTM F2792-12a standard. This strategy involves several different independent and dependent thermal cycles, all of which have an influence on the final properties of the manufactured part. The quality of PBF parts depends strongly on the characteristics of each single laser-melted track and each single layer. This study consequently concentrates on investigating the effects of process parameters such as laser power on single track and layer formation and laser-material interaction phenomena occurring during the PBF process. Experimental tests were done with two different machines: a modified research machine based on an EOS EOSINT M-series system and an EOS EOSINT M280 system. The material used was EOS stainless steel 17-4 PH. Process monitoring was done with an active illuminated high speed camera system. After microscopy analysis, it was concluded that a keyhole can form during laser additive manufacturing of stainless steel. It was noted that heat input has an important effect on the likelihood of keyhole formation. The threshold intensity value for keyhole formation of 106 W/cm2 was exceeded in all manufactured single tracks. Laser interaction time was found to have an effect on penetration depth and keyhole formation, since the penetration depth increased with increased laser interaction time. It was also concluded that active illuminated high speed camera systems are suitable for monitoring of the manufacturing process and facilitate process control.

  10. Multiscale correlative tomography: an investigation of creep cavitation in 316 stainless steel.

    PubMed

    Slater, T J A; Bradley, R S; Bertali, G; Geurts, R; Northover, S M; Burke, M G; Haigh, S J; Burnett, T L; Withers, P J

    2017-08-04

    Creep cavitation in an ex-service nuclear steam header Type 316 stainless steel sample is investigated through a multiscale tomography workflow spanning eight orders of magnitude, combining X-ray computed tomography (CT), plasma focused ion beam (FIB) scanning electron microscope (SEM) imaging and scanning transmission electron microscope (STEM) tomography. Guided by microscale X-ray CT, nanoscale X-ray CT is used to investigate the size and morphology of cavities at a triple point of grain boundaries. In order to understand the factors affecting the extent of cavitation, the orientation and crystallographic misorientation of each boundary is characterised using electron backscatter diffraction (EBSD). Additionally, in order to better understand boundary phase growth, the chemistry of a single boundary and its associated secondary phase precipitates is probed through STEM energy dispersive X-ray (EDX) tomography. The difference in cavitation of the three grain boundaries investigated suggests that the orientation of grain boundaries with respect to the direction of principal stress is important in the promotion of cavity formation.

  11. Preliminary investigation of steel compatibility with potential materials of construction for UF6 cylinder chocks

    SciTech Connect

    Pawel, S.J.; Ziehlke, K.T.; Swindeman, C.J.

    1992-12-01

    A set of compatibility experiments was performed to assess corrosion susceptibility of mild steel in long term contact with UF{sub 6} cylinder chocking materials and the atmosphere. Chock materials considered included concrete, pressure-treated wood, and creosote-treated wood. Immersion tests (panels partially submerged, 1000 h, 38 C), resistance probe measurements (600 h, ambient), and cyclic polarization tests on steel in leachate solutions generated from each chock material were performed. Results indicate that the long term corrosion susceptibility of mild steel in contact with concrete and the atmosphere is at least the equivalent of -- and under some conditions superior to -- that for steel in contact with pressure-treated or creosote-treated wood. No corrosion-related limitation for concrete chocks for long term support of mild steel UF{sub 6} cylinders was identified.

  12. Investigation on Adsorption and the Corrosion Inhibition Effect of Some Novel Hydrazide Derivatives for Mild Steel in HCl Solution

    NASA Astrophysics Data System (ADS)

    Singh, Dharmendra Kumar; Behera, Debasis; Singh, Mantu Kumar; Udayabhanu, G.; John, Rohith P.

    2017-10-01

    Two hydrazide derivatives, namely, N'-(thiophene-2-ylmethylene)nicotinic hydrazone (TNH) and N'-(pyrrol-2-ylmethylene)nicotinic hydrazone (PNH), have been synthesized and investigated as corrosion inhibitors for mild steel in 1 M HCl solution by electrochemical, weight loss, field emission-scanning electron microscope (FE-SEM), atomic force microscope (AFM), and quantum chemical calculation methods. The experimental results show that both the compounds are good inhibitors for mild steel in 1 M HCl. They act as mixed type inhibitors with predominating cathodic character. The adsorption of inhibitors obeys the Langmuir adsorption isotherm. Correlation between quantum chemical parameters and experimental results is discussed.

  13. Quartz Crystal Microbalance Investigation of the Structure of Adsorbed Soybean Oil and Methyl Oleate onto Steel Surface

    USDA-ARS?s Scientific Manuscript database

    The adsorption of soybean oil (SBO) and methyl oleate (MO) onto steel was investigated using quartz crystal microbalance with dissipation monitoring (QCM-D). Adsorption of both SBO and MO increased with increasing concentrations. At full surface coverage, SBO and MO formed rigid thin films and ach...

  14. Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale

    NASA Astrophysics Data System (ADS)

    Hossain, R.; Pahlevani, F.; Quadir, M. Z.; Sahajwalla, V.

    2016-10-01

    Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels’ performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano scale of the compressive stability of retained austenite in high carbon martensitic steel. Using a combination of standard compression testing, X-ray diffraction, optical microstructure, electron backscattering diffraction imaging, electron probe micro-analysis, nano-indentation and micro-indentation measurements, we determined the mechanical stability of retained austenite and martensite in high carbon steel under compressive stress and identified the phase transformation mechanism, from the macro to the nano level. We found at the early stage of plastic deformation hexagonal close-packed (HCP) martensite formation dominates, while higher compression loads trigger body-centred tetragonal (BCT) martensite formation. The combination of this phase transformation and strain hardening led to an increase in the hardness of high carbon steel of around 30%. This comprehensive characterisation of stress induced phase transformation could enable the precise control of the microstructures of high carbon martensitic steels, and hence their properties.

  15. Atomic scale investigation of non-equilibrium segregation of boron in a quenched Mo-free martensitic steel.

    PubMed

    Li, Y J; Ponge, D; Choi, P; Raabe, D

    2015-12-01

    B-added low carbon steels exhibit excellent hardenability. The reason has been frequently attributed to B segregation at prior austenite grain boundaries, which prevents the austenite to ferrite transformation and favors the formation of martensite. The segregation behavior of B at prior austenite grain boundaries is strongly influenced by processing conditions such as austenitization temperatures and cooling rates and by alloying elements such as Mo, Cr, and Nb. Here an local electrode atom probe was employed to investigate the segregation behavior of B and other alloying elements (C, Mn, Si, and Cr) in a Cr-added Mo-free martensitic steel. Similar to our previous results on a Mo-added steel, we found that in both steels B is segregated at prior austenite grain boundaries with similar excess values, whereas B is neither detected in the martensitic matrix nor at martensite-martensite boundaries at the given cooling rate of 30K/s. These results are in agreement with the literature reporting that Cr has the same effect on hardenability of steels as Mo in the case of high cooling rates. The absence of B at martensite-martensite boundaries suggests that B segregates to prior austenite grain boundaries via a non-equilibrium mechanism. Segregation of C at all boundaries such as prior austenite grain boundaries and martensite-martensite boundaries may occur by an equilibrium mechanism.

  16. Stability of retained austenite in high carbon steel under compressive stress: an investigation from macro to nano scale

    PubMed Central

    Hossain, R.; Pahlevani, F.; Quadir, M. Z.; Sahajwalla, V.

    2016-01-01

    Although high carbon martensitic steels are well known for their industrial utility in high abrasion and extreme operating environments, due to their hardness and strength, the compressive stability of their retained austenite, and the implications for the steels’ performance and potential uses, is not well understood. This article describes the first investigation at both the macro and nano scale of the compressive stability of retained austenite in high carbon martensitic steel. Using a combination of standard compression testing, X-ray diffraction, optical microstructure, electron backscattering diffraction imaging, electron probe micro-analysis, nano-indentation and micro-indentation measurements, we determined the mechanical stability of retained austenite and martensite in high carbon steel under compressive stress and identified the phase transformation mechanism, from the macro to the nano level. We found at the early stage of plastic deformation hexagonal close-packed (HCP) martensite formation dominates, while higher compression loads trigger body-centred tetragonal (BCT) martensite formation. The combination of this phase transformation and strain hardening led to an increase in the hardness of high carbon steel of around 30%. This comprehensive characterisation of stress induced phase transformation could enable the precise control of the microstructures of high carbon martensitic steels, and hence their properties. PMID:27725722

  17. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semi-logarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  18. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semilogarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  19. Experimental investigation and statistical optimisation of the selective laser melting process of a maraging steel

    NASA Astrophysics Data System (ADS)

    Casalino, G.; Campanelli, S. L.; Contuzzi, N.; Ludovico, A. D.

    2015-01-01

    Selective Laser Melting (SLM) is an Additive Manufacturing process (AM) that built parts from powder using a layer-by-layer deposition technique. The control of the parameters that influence the melting and the amount of energy density involved in the process is paramount in order to get valuable parts. The objective of this paper is to perform an experimental investigation and a successive statistical optimization of the parameters of the selective laser melting process of the 18Ni300 maraging steel. The experimental investigation involved the study of the microstructure, the mechanical and surface properties of the laser maraging powder. The outcomes of experimental study demonstrated that the hardness, the mechanical strength and the surface roughness correlated positively to the part density. Parts with relative density higher than 99% had a very low porosity that presented closed and regular shaped pores. The statistical optimization determined that the best part properties were produced with the laser power bigger than 90 W and the velocity smaller than 220 mm/s.

  20. Investigation of Low-Cycle Bending Fatigue of AISI 9310 Steel Spur Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Krantz, Timothy L.; Lerch, Bradley A.; Burke, Christopher S.

    2007-01-01

    An investigation of the low-cycle bending fatigue of spur gears made from AISI 9310 gear steel was completed. Tests were conducted using the single-tooth bending method to achieve crack initiation and propagation. Tests were conducted on spur gears in a fatigue test machine using a dedicated gear test fixture. Test loads were applied at the highest point of single tooth contact. Gear bending stresses for a given testing load were calculated using a linear-elastic finite element model. Test data were accumulated from 1/4 cycle to several thousand cycles depending on the test stress level. The relationship of stress and cycles for crack initiation was found to be semilogarithmic. The relationship of stress and cycles for crack propagation was found to be linear. For the range of loads investigated, the crack propagation phase is related to the level of load being applied. Very high loads have comparable crack initiation and propagation times whereas lower loads can have a much smaller number of cycles for crack propagation cycles as compared to crack initiation.

  1. Investigation of surface parameters during hot air streaming turning process of mild steel

    NASA Astrophysics Data System (ADS)

    Patwari, Anayet U.; Habib, Mohammad Ahsan; Mahmud, Md. Firoz; Islam, Md. Minhazul

    2017-06-01

    Different types of coolant are widely used in different metal cutting processes to improve the machining responses. But the suitability of using the correct cutting fluid is very important considering the concept of green environment. In this study, hot air is used as an alternative approach for hot machining process and coolant. Hot air is considered to initially heat the work-piece for easy machining operation. In this study, two different velocities of hot air has been applied during the machining of mild steel in turning process and its effect is investigated in terms of surface roughness. With the variation of different process parameters, it has also been observed that surface roughness at different cutting conditions using hot air is improved significantly. A clear comparison has been made to investigate the responses of surface roughness at different cutting conditions in between the hot air and normal machining processes. This procedure may be used as an alternative approach in the dry cutting research in the days to come.

  2. Investigations on Surface Milling of Hardened AISI 4140 Steel with Pulse Jet MQL Applicator

    NASA Astrophysics Data System (ADS)

    Bashir, Mahmood Al; Mia, Mozammel; Dhar, Nikhil Ranjan

    2016-06-01

    In this article, an experimental investigation was performed in milling hardened AISI 4140 steel of hardness 40 HRC. The machining was performed in both dry and minimal quantity lubricant (MQL) conditions, as part of neat machining, to make a strong comparison of the undertaken machining environments. The MQL was impinged int the form of pulse jet, by using the specially developed pulse-jet-attachment, to ensure that the cutting fluid can be applied in different timed pulses and quantities at critical zones. The tool wear, cutting force and surface roughness were taken as the quality responses while cutting speed, table feed rate and flow rate of the pulse were considered as influential factors. The depth of cut was kept constant at 1.50 mm because of its less significant effects and the straight oil was adopted as cutting fluid in pulse-jet-MQL. The effects of different factors, on the quality responses, are analyzed using ANOVA. It is observed that MQL applicator system exhibits overall better performance when compared to dry milling by reducing surface roughness, cutting force and prolonging tool life but a flow rate of 150 ml/h has tremendous effects on the responses. This investigation and afterward results are expected to aid the industrial practitioner and researcher to adopt the pulse-MQL in high speed milling to prolong tool life, reduce tool wear, diminish cutting force generation and promote better surface finish.

  3. Experimental investigation on selective laser melting of 17-4PH stainless steel

    NASA Astrophysics Data System (ADS)

    Hu, Zhiheng; Zhu, Haihong; Zhang, Hu; Zeng, Xiaoyan

    2017-01-01

    Selective laser melting (SLM) is an additive manufacturing (AM) technique that uses powders to fabricate 3Dparts directly. The objective of this paper is to perform an experimental investigation of selective laser melted 17-4PH stainless steel. The investigation involved the influence of separate processing parameters on the density, defect, microhardness and the influence of heat-treatment on the mechanical properties. The outcomes of this study show that scan velocity and slice thickness have significant effects on the density and the characteristics of pores of the SLMed parts. The effect of hatch spacing depends on scan velocity. The processing parameters, such as scan velocity, hatch spacing and slice thickness, have effect on microhardness. Compared to the samples with no heat-treatment, the yield strength of the heat-treated sample increases significantly and the elongation decreases due to the transformation of microstructure and the changes in the precipitation strengthening phases. By a combination of changes in composition and precipitation strengthening, microhardness improved.

  4. Investigation of steel thickness measurement by an electromagnetic method using a step exciting current

    SciTech Connect

    Naruse, Takeshi; Shimada, Michio; Yoshii, Tokuharu

    1998-05-01

    The electromagnetic measurement of steel thickness was noted as a new method for inspecting corroded surfaces of ship structures. Experiments to measure the electromagnetic response of steel and simulations using finite element methods (FEM) were carried out. Two peaks appeared in the induced voltage waveforms obtained from the sensing coil (situated on the opposite side of the steel plate from the exciting coil) as the response to a step exciting current. It was found that the peak that appeared first was the response of the magnetic flux that came around the steel plate, while the second peak was the response of the magnetic flux that penetrated the steel plate. Three values, amplitude, delay time, and half value breadth (HVB) were defined in both peaks. All the values from the second peak were correlated to the thickness of steel. Delay time was expected to be the most useful value, which was most stable for the effect of exciting and sensing coil lift-off and amplitude of the step exciting current. The permeability of steel had great effect on the values, but the slits in the specimens had only a minimal effect.

  5. The Results Of The Investigation Of Thermomechanical Processing Of PM Steel

    SciTech Connect

    Szczepanik, Stefan; Wisniewski, Bartosz; Krawiarz, Jerzy

    2007-04-07

    Hot die forging of PM steel is used to obtain products with high densities. The combination of this process with heat treatment of forgings directly after their forming is researched in order to reduce energy consumption in the manufacture of PM steel products. This work determined the influence of the cooling ratio directly after hot forging of PM steel samples on their structure and mechanical properties. The properties of the PM preforms were examined after sintering and after sintering, quenching into water and tempering for 1 h at 250, 350 and 550 deg. C, respectively, as well as after forging at given temperatures and cooling in water and air, respectively. Forged steel after quenching was tempered at the same temperature as the sintered samples. Good mechanical properties were obtained by hot forging at 1100 deg. C. Sintered steel with 0.6 % Cgraphite is characterized by good hardenability and is susceptible to plastic forming at 1100 - 940 deg. C. During its cooling in air a bainitic-martensitic structure is obtained, whereas after cooling in water the structure is martensitic. The properties of the forged steel are strongly dependent on deformation temperature and cooling conditions. The tensile strength of the forged PM steel with 0.6 Cgraphite after forming at 1100 deg. C is much higher than that of the same heat-treated as-sintered steel. Traditional heat treatment applied to materials after deformation at 1100 deg. C slightly increases properties in comparison to the material directly quenched into water. The best strength was 1585 {+-} 193 MPa, bending strength 3364 {+-} 142 MPa and hardness 588 {+-} 43 HB. Application of controlled cooling of sintered PM steel directly after close-die forging diminishes the energy consumption during product manufacture.

  6. The Results Of The Investigation Of Thermomechanical Processing Of PM Steel

    NASA Astrophysics Data System (ADS)

    Szczepanik, Stefan; Wiśniewski, Bartosz; Krawiarz, Jerzy

    2007-04-01

    Hot die forging of PM steel is used to obtain products with high densities. The combination of this process with heat treatment of forgings directly after their forming is researched in order to reduce energy consumption in the manufacture of PM steel products. This work determined the influence of the cooling ratio directly after hot forging of PM steel samples on their structure and mechanical properties. The properties of the PM preforms were examined after sintering and after sintering, quenching into water and tempering for 1 h at 250, 350 and 550°C, respectively, as well as after forging at given temperatures and cooling in water and air, respectively. Forged steel after quenching was tempered at the same temperature as the sintered samples. Good mechanical properties were obtained by hot forging at 1100 °C. Sintered steel with 0.6 % Cgraphite is characterized by good hardenability and is susceptible to plastic forming at 1100 - 940 °C. During its cooling in air a bainitic-martensitic structure is obtained, whereas after cooling in water the structure is martensitic. The properties of the forged steel are strongly dependent on deformation temperature and cooling conditions. The tensile strength of the forged PM steel with 0.6 Cgraphite after forming at 1100°C is much higher than that of the same heat-treated as-sintered steel. Traditional heat treatment applied to materials after deformation at 1100 °C slightly increases properties in comparison to the material directly quenched into water. The best strength was 1585 ± 193 MPa, bending strength 3364 ± 142 MPa and hardness 588 ± 43 HB. Application of controlled cooling of sintered PM steel directly after close-die forging diminishes the energy consumption during product manufacture.

  7. Investigation of Microstructure and Mechanical Properties of St37 Steel-Ck60 Steel Joints by Explosive Cladding

    NASA Astrophysics Data System (ADS)

    Yazdani, Majid; Toroghinejad, Mohammad Reza; Hashemi, Seyyed Mohammad

    2015-10-01

    The present work aimed at studying the microstructure and mechanical properties of Ck60/St37 composite plates fabricated by explosive cladding. The explosive ratio and stand-off distance were set to be R = 1.7 and s = 1.5 t, respectively. Optical and scanning electron microscopy revealed that the bonding at the interface had a wavy morphology, but local melted zones were formed along the interface. The chemical composition of the local melted zones was evaluated by energy-dispersive spectroscopy analysis. This analysis showed that the melted zones consisted of both Ck60 and St37 steels. The maximum hardness was obtained near the explosively cladded interface; then these values were decreased by the distance away from the interface. Moreover, it was seen that the local melted zones, especially the vortices, had a high degree of hardness. Shear tests on the cladded metals also showed that the average shear strength was higher than 140 MPa, as set by the ASTM A263-12, implying that composite plates could be used safely. The study was also conducted to consider the strength of bonding by bending test in two ways, one with the cladding metal in tension and the other with the cladding metal in compression. Bending test results showed that these joints could be used safely when the cladded metal was in compression; otherwise, it would be fractured. Finally, impact test results showed that the fracture toughness of cladded samples was higher than that of flyer material due to the higher fracture toughness of the base material.

  8. Atom probe tomography investigation of assisted precipitation of secondary hardening carbides in a medium carbon martensitic steels.

    PubMed

    Danoix, F; Danoix, R; Akre, J; Grellier, A; Delagnes, D

    2011-12-01

    A medium carbon martensitic steel containing nanometer scale secondary hardening carbides and intermetallic particles is investigated by field ion microscopy and atom probe tomography. The interaction between the concomitant precipitations of both types of particles is investigated. It is shown that the presence of the intermetallic phase affects the nucleation mechanism and the spatial distribution of the secondary hardening carbides, which shifts from heterogeneous on dislocations to heterogeneous on the intermetallic particles.

  9. 76 FR 23559 - Certain Steel Nails From the United Arab Emirates: Initiation of Antidumping Duty Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... steel nails from the United Arab Emirates (UAE) filed in proper form by Mid Continent Nail Corporation... petitioner made adjustments for foreign inland freight, foreign port expenses, ocean freight, U.S....

  10. Neural Modeling and Experimental Investigation of the Erosion Characteristics of Boiler Grade Steels Impacted by Fly Ash

    NASA Astrophysics Data System (ADS)

    Das, S. K.; Mandal, Durbadal; Sahoo, K. L.

    2015-09-01

    In this study, experimental investigations on solid particle erosion have been carried out for two typical boiler grade steels used for fabricating boiler components, namely, 0.22C steel and 1.25Cr-Mo-V steel. The erosion tests were conducted using an air jet erosion testing facility conforming to ASTM Standard G76 international testing method. Impingement angle of the air-particle stream on the target material was varied from 30° to 75°, and the particle impact velocity was also varied from 40 to 150 m/s. The surface morphology of the eroded samples was investigated by SEM to elucidate the erosion mechanism under different particle impact conditions. Further, an artificial neural network (ANN) model has been developed to predict the erosion behavior of these boiler grade steels impacted by boiler fly ash for more realistic characterization of erosion potential using pertinent data. An efficient network training optimization algorithm has been employed for faster convergence and better predictions. The ANN predictions of erosion rate are found to be in excellent agreement with the actual measured data as reported in the literature. It has been observed from the neural model results that the erosion potential of actual boiler fly ash with various levels of silica content is considerably higher than the synthetic erodent (alumina particles) usually used in the experiments to mimic fly ash erosion behavior under simulated conditions.

  11. Investigation of panel crack formation in steel ingots: Part I. Mathematical analysis and mid face panel cracks

    NASA Astrophysics Data System (ADS)

    Thomas, B. G.; Samarasekera, I. V.; Brimacombe, J. K.

    1988-04-01

    An investigation of panel crack formation in steel ingots has been undertaken to improve understanding of the mechanisms by which the cracks develop and to evaluate possible solutions to this problem that has plagued the steel industry intermittently for decades. The investigation features the application of two-dimensional, finite-element, heat-flow, and stress models, which have been described in earlier publications1,2 for steel ingot processing. The model predictions have clarified the role of stress generation in panel crack formation and demonstrate the importance of the γ→ α phase transformation. It has been revealed that two distinct types of panel cracks, both of which are partly caused by intermediate-temperature embrittlement of steel involving aluminum nitride precipitation, operate under different mechanisms. Mid-face panel cracks, which are analyzed in Part I of this paper, apparently form during air cooling when the mid-face surface is between the Ar1 and 500 °C. The cracks can be prevented by ensuring the ingot surface does not cool below the Ar1, and preferably the Ar3 temperature. In case of a 335 mm square ingot, this would require reheating and rolling within the first hour after being stripped from the mold. Alternatively charging the ingots to a holding furnace to slow the surface cooling rate through the critical Ar1 - 500 °C temperature zone should be beneficial. Off-corner panel cracks are discussed in Part II.

  12. Behaviour and Analysis of Steel and Macro-Synthetic Fibre Reinforced Concrete Subjected to Reversed Cyclic Loading: A Pilot Investigation

    NASA Astrophysics Data System (ADS)

    Carnovale, David Joseph

    The benefits of fibre reinforced concrete (FRC) have been thoroughly investigated. Much of this work has focussed on steel FRC subjected to monotonic loads. Data on the structural behaviour of macro-synthetic FRC or FRC under cyclic loads is scarce. A pilot investigation on the shear behaviour of macro-synthetic FRC and on the behaviour of FRC under reversed cyclic in-plane shear loading was carried out. Five in-plane shear panel tests were performed. The parameters under study were the fibre material type (steel or macrosynthetic) and loading protocol. Additionally, a number of compression, direct tension, and flexural tests were performed to determine the material properties of the concretes for comparison. The material response of 2.0% by volume of macro-synthetic FRC matched closely with 1.0% steel FRC. Finally, building upon an existing steel FRC model, a model for macro-synthetic FRC in tension was proposed and a short verification study was undertaken.

  13. Electrochemical investigation of stainless steel corrosion in a proton exchange membrane electrolyzer cell

    DOE PAGES

    Mo, Jingke; Steen, Stuart M.; Zhang, Feng-Yuan; ...

    2015-08-05

    The lack of a fundamental understanding of the corrosion mechanisms in the electrochemical environments of proton exchange membrane (PEM) electrolyzer and/or fuel cells (ECs/FCs) has seriously hindered the improvement of performance and efficiency of PEM ECs/FCs. In this study, a stainless steel mesh was purposely used as an anode gas diffusion layer that was intentionally operated with high positive potentials under harsh oxidative environments in a PEMEC to study the corrosion mechanism of metal migration. A significant amount of iron and nickel cations were determined to transport through the anode catalyst layer, the PEM and the cathode catalyst layer duringmore » the PEMEC operation. The formation/deposition of iron oxide and nickel oxide on the carbon paper gas diffusion layer at the cathode side is first revealed by both scanning electron microscope and X-ray diffraction. The results indicate the corrosion elements of iron and nickel are transported from anode to cathode through the catalyst-coated membrane, and deposited on carbon fibers as oxides. This phenomenon could also open a new corrosion-based processing approach to potentially fabricate multifunctional oxide structures on carbon fiber devices. This study has demonstrated a new accelerated test method for investigating the corrosion and durability of metallic materials as well.« less

  14. Electrochemical investigation of stainless steel corrosion in a proton exchange membrane electrolyzer cell

    SciTech Connect

    Mo, Jingke; Steen, Stuart M.; Zhang, Feng-Yuan; Toops, Todd J.; Brady, Michael P.; Green, Johney B.

    2015-08-05

    The lack of a fundamental understanding of the corrosion mechanisms in the electrochemical environments of proton exchange membrane (PEM) electrolyzer and/or fuel cells (ECs/FCs) has seriously hindered the improvement of performance and efficiency of PEM ECs/FCs. In this study, a stainless steel mesh was purposely used as an anode gas diffusion layer that was intentionally operated with high positive potentials under harsh oxidative environments in a PEMEC to study the corrosion mechanism of metal migration. A significant amount of iron and nickel cations were determined to transport through the anode catalyst layer, the PEM and the cathode catalyst layer during the PEMEC operation. The formation/deposition of iron oxide and nickel oxide on the carbon paper gas diffusion layer at the cathode side is first revealed by both scanning electron microscope and X-ray diffraction. The results indicate the corrosion elements of iron and nickel are transported from anode to cathode through the catalyst-coated membrane, and deposited on carbon fibers as oxides. This phenomenon could also open a new corrosion-based processing approach to potentially fabricate multifunctional oxide structures on carbon fiber devices. This study has demonstrated a new accelerated test method for investigating the corrosion and durability of metallic materials as well.

  15. Experimental investigation of the transformation texture in hotrolled ferritic stainless steel using single orientation determination

    NASA Astrophysics Data System (ADS)

    Raabe, D.; Ylitalo, M.

    1996-01-01

    Two ferritic stainless steels (≈16.5 mass pct Cr) were hot-rolled using seven subsequent passes. The first sample was rolled within the range 1280 °C to 750 °C, i.e., the deformation started in the ferritic region. The second sample was rolled within the range 1080 °C to 770 °C, i.e., the deformation started in the ferritic-austenitic region. In both cases, up to 40 vol pct of the ferrite transformed into austenite during hot rolling. During the last passes, the austenite transformed into cubic martensite. After hot rolling, these former austenitic regions were identified using a selective etching technique and examined using single orientation determination in the scanning electron microscope. The regions which remained ferritic throughout the hot-rolling process were investigated as well. Whereas the texture of the martensite considerably depended on the hot-rolling conditions, especially on the temperature and on the intervals between the rollings, the texture of the ferrite was less affected. The textures of the martensite were interpreted in terms of the crystallographic transformation rules between austenite and martensite. The textures of the ferrite were discussed in terms of recovery and recrystallization.

  16. An investigation on microstructure and mechanical property of thermally aged stainless steel weld overlay cladding

    NASA Astrophysics Data System (ADS)

    Cao, X. Y.; Zhu, P.; Ding, X. F.; Lu, Y. H.; Shoji, T.

    2017-04-01

    Microstructural evolution and mechanical property change of E308L stainless steel weld overlay cladding aged at 400 °C for 400, 1000 and 5000 h were investigated by transmission electron microscope (TEM) and small punch test (SPT). The results indicated that thermal aging had no obvious effect on the volume fraction of ferrite, but can cause microstructural evolution by spinodal decomposotion and G-phase precipitation in the ferrite phase. Spinodal decomposition took place after aging up to 1000 h, while G-phase formed along dislocations, and growed up to 2-11 nm after aging for 5000 h. The total energy for inducing deformation and fracture by the small punch tests decreased with the increase of thermal aging time, and this decline was associated with spinodal decomposition and G-phase precipitation. Plastic deformation of the aged ferrite proceeded via formation of curvilinear slip bands. Nucleation of microcracks occurred at the δ/γ interface along the slip bands. The hardening of the ferrite and high stress concentration on δ/γ phase interface resulted in brittle fracture and phase boundary separation after thermal aging.

  17. Microstructural investigation, using polarized neutron scattering, of a martensitic steel for fusion reactors

    SciTech Connect

    Coppola, R.; Kampmann, R.; Staron, P.; Magnani, M.

    1998-09-18

    Small- and wide-angle polarized neutron scattering has been used to investigate the microstructure of modified martensitic steel DIN 1.4914 (MANET-type) developed as a potential candidate for the first wall of future fusion reactors. The nuclear-magnetic interference term and the comparison of the size distribution functions, obtained from the nuclear and from the magnetic scattering components, show that for quench temperatures lower than 1200 C three kinds of microstructural inhomogeneities can be identified: (a) tiny C-Cr elementary aggregates (1 nm or less in size), (b) larger (1--25 nm) Fe-carbides, (c) much larger inhomogeneities arising either from M{sub 23}C{sub 6} precipitates or from fluctuations in the Cr distribution. The scattering data are also compared with those previously obtained on the same samples from a conventional SANS instrument and the influence of the available Q-range on the accuracy of the obtained size distribution functions is discussed.

  18. Atom probe tomography investigation of lath boundary segregation and precipitation in a maraging stainless steel.

    PubMed

    Thuvander, Mattias; Andersson, Marcus; Stiller, Krystyna

    2013-09-01

    Lath boundaries in a maraging stainless steel of composition 13Cr-8Ni-2Mo-2Cu-1Ti-0.7Al-0.3Mn-0.2Si-0.03C (at%) have been investigated using atom probe tomography following aging at 475 °C for up to 100 h. Segregation of Mo, Si and P to the lath boundaries was observed already after 5 min of aging, and the amount of segregation increases with aging time. At lath boundaries also precipitation of η-Ni₃(Ti, Al) and Cu-rich 9R, in contact with each other, takes place. These co-precipitates grow with time and because of coarsening the area number density decreases. After 100 h of aging a ∼5 nm thick film-like precipitation of a Mo-rich phase was observed at the lath boundaries. From the composition of the film it is suggested that the phase in question is the quasicrystalline R' phase. The film is perforated with Cu-rich 9R and η-Ni₃(Ti, Al) co-precipitates. Not all precipitate types present in the matrix do precipitate at the lath boundaries; the Si-containing G phase and γ'-Ni₃(Ti, Al, Si) and the Cr-rich α' phase were not observed at the lath boundaries.

  19. Experimental investigation on vortex-induced vibration of steel catenary riser

    NASA Astrophysics Data System (ADS)

    Fan, Yu-ting; Mao, Hai-ying; Guo, Hai-yan; Liu, Qing-hai; Li, Xiao-min

    2015-10-01

    Steel catenary riser (SCR) is the transmission device between the seabed and the floating production facilities. As developments move into deeper water, the fatigue life of the riser can become critical to the whole production system, especially due to the vortex-induced vibration (VIV), which is the key factor to operational longevity. As a result, experimental investigation about VIV of the riser was performed in a large plane pool which is 60 m long, 36 m wide and 6.5 m deep. Experiments were developed to study the influence of current speed and seabed on VIV of SCR. The results show that amplitudes of strain and response frequencies increase with the current speed both in cross-flow (CF) and in-line (IL). When the current speed is high, multi-mode response is observed in the VIV motion. The amplitudes of strain in IL direction are not much smaller than those in CF direction. The seabed has influence on the response frequencies of riser and the positions of damage for riser.

  20. An investigation of the properties of conventional and severe shot peened low alloy steel

    NASA Astrophysics Data System (ADS)

    Quang Trung, Pham; Butler, David Lee; Win Khun, Nay

    2017-07-01

    The effects of the conventional shot peening and severe shot peening process on the mechanical and tribological properties of shot peened AISI 4340 high strength steel were systematically investigated. Compared with the conventional shot peened sample, the ultrafine grain surface layer with a depth of about 20 µm generated by the severe shot peening process can enhance the hardness and wear resistance of the treated material. However, deeper dimples generated by the high media velocity in the severe shot peening process resulted in a higher surface roughness, which is considered as a side effect of this method reducing the fatigue life of the material. Applying a smaller shot size with an appropriate intensity can be used to peen the severe shot peened samples to not only reduce the surface roughness and friction coefficient but also improve the wear resistance for these samples. This work was presented in the shot peening section during ‘The 30th International Conference on Surface Modification Technologies, 2016, Milan, Italy’ (SMT30, ID 61, entitled ‘Comparison of the effects of conventional shot peening and severe shot peening processes on the mechanical and tribological properties of shot peened AISI 4340’) and the authors were encouraged to submit a manuscript to the Materials Research Express journal after adding some nessesary information.

  1. Further investigation of critical events in cleavage fracture of C-Mn base and weld steel

    SciTech Connect

    Chen, J.H.; Zhu, L.; Wang, G.Z.; Wang, Z. )

    1993-03-01

    In this work, an investigation of the critical event in cleavage fracture of C-Mn base and weld steel was carried out. The fracture surfaces and the remaining cracks in the vicinities of notches and precracks in the double-notched specimens (DNBs) and precracked crack opening displacement (COD) test specimens unloaded prior to fracture were observed in detail. The results demonstrate that critical events are different in notched and precracked specimens even if they are made of identical materials. For the notched specimens with the radius of notch roots from 0.075 to 0.45 mm, critical events in cleavage fracture are the propagation of the ferrite grain-sized microcracks (FCs) into the neighboring ferrite grains. However, for the precracked specimens fractured at [minus] 110 C, critical events are the propagation of the second-phase particle-sized microcracks (SCs) into matrix ferrite grains. For the precracked specimens tested at [minus]70 C, critical events could be the propagation of either SCs or FCs depending on the blunted width of precrack prior to fracture. The cleavage fracture at [minus]196 C is controlled by the nucleation of the microcrack; there were no remaining cracks found in specimens unloaded prior to fracture. With a drop in the test temperature or decrease in the radius of notch root, the length of the critical crack decreases.

  2. Nano-indentation investigation on the mechanical stability of individual austenite in high-carbon steel

    SciTech Connect

    Qiao, Xun; Han, Lizhan; Zhang, Weimin; Gu, Jianfeng

    2015-12-15

    Quenching (AQ) and cryogenic treatments (QC) were conducted on the high-carbon SAE 52100 steel to investigate the mechanical stability of individual retained austenite (RA) by nano-indentation. The cross-sections of indented RA region prepared by focused ion beam (FIB) were examined by using transmission electron microscopy (TEM). For the first time, it was directly observed that some parts of RA grain, closest to the indent, in AQ specimen had transformed into strain-induced martensite (SIM). However, not any pop-in or transformation was detected in the indented QC specimen. This clearly indicates that the mechanical stability of RA in QC seems significantly enhanced, which is mainly attributed to the cryogenic treatment resulting in a higher carbon enrichment of RA compared to that in AQ. Furthermore, a higher load of external stress may need to trigger its martensitic transformation in QC specimen. - Highlights: • Mechanical stability of retained austenite was studied by nano-indentation and TEM. • The strain-induced martensite transformation in RA was observed under applied load. • Cryogenic treatment enhances mechanical stability of RA due to carbon enrichment.

  3. Investigations of morphological features of picosecond dual-wavelength laser ablation of stainless steel

    NASA Astrophysics Data System (ADS)

    Zhao, Wanqin; Wang, Wenjun; Mei, Xuesong; Jiang, Gedong; Liu, Bin

    2014-06-01

    Investigations on the morphological features of holes and grooves ablated on the surface of stainless steel using the picosecond dual-wavelength laser system with different powers combinations are presented based on the scarce researches on morphology of dual-wavelength laser ablation. The experimental results show the profiles of holes ablated by the visible beam appear V-shaped while those for the near-infrared have large openings and display U-shaped, which are independent of the ablation mechanism of ultrafast laser. For the dual-wavelength beam (a combination of visible beam and near-infrared), the holes resemble sunflower-like structures and have smoother ring patterns on the bottom. In general, the holes ablated by the dual-wavelength beam appear to have much flatter bottoms, linearly sloped side-walls and spinodal structures between the bottoms of the holes and the side-walls. Furthermore, through judiciously combining the powers of the dual-wavelength beam, high-quality grooves could be obtained with a flat worm-like structure at the bottom surface and less resolidified melt ejection edges. This study provides insight into optimizing ultrafast laser micromachining in order to obtain desired morphology.

  4. Preliminary Investigation on Life Cycle Inventory of Powder Bed Fusion of Stainless Steel

    NASA Astrophysics Data System (ADS)

    Nyamekye, Patricia; Piili, Heidi; Leino, Maija; Salminen, Antti

    Manufacturing of work pieces from stainless steel with laser additive manufacturing, known also as laser sintering or 3D printing may increase energy and material efficiency. The use of powder bed fusion offers advantages to make parts for dynamic applications of light weight and near-net-shape products. Due to these advantages among others, PBF may also reduce emissions and operational cost in various applications. However, there are only few life cycle assessment studies examining this subject despite its prospect to business opportunity. The application of Life Cycle Inventory (LCI) in Powder Bed Fusion (PBF) provides a distinct evaluation of material and energy consumption. LCI offers a possibility to improve knowledge of process efficiency. This study investigates effect of process sustainability in terms of raw material, energy and time consumption with PBF and CNC machining. The results of the experimental study indicated lower energy efficiency in the production process with PBF. This study revealed that specific energy consumption in PBF decreased when several components are built simultaneously than if they would be built individually. This is due to fact that energy consumption per part is lower. On the contrary, amount of energy needed to machine on part in case of CNC machining is lower when parts are done separately.

  5. Investigations on Laser Beam Welding of Different Dissimilar Joints of Steel and Aluminum Alloys for Automotive Lightweight Construction

    NASA Astrophysics Data System (ADS)

    Seffer, Oliver; Pfeifer, Ronny; Springer, André; Kaierle, Stefan

    Due to the enormous potential of weight saving, and the consequential reduction of pollutant emissions, the use of hybrid components made of steel and aluminum alloys is increasing steadily, especially concerning automotive lightweight construction. However, thermal joining of steel and aluminum is still being researched, due to a limited solubility of the binary system of iron and aluminum causing the formation of hard and brittle intermetallic phases, which decrease the strength and the formability of the dissimilar seam. The presented results show the investigation of laser beam welding for joining different dissimilar hybrid components of the steel materials HX220LAD+Z100, 22MnB5+AS150 and 1.4301, as well as the aluminum alloy AA6016-T4 as a lap joint. Among other things, the influences of the energy per unit length, the material grade, the sheet thickness t, the weld type (lap weld, fillet weld) and the arrangement of the base materials in a lap joint (aluminum-sided irradiation, steel-sided irradiation) on the achievable strengths are analyzed. The characterization of the dissimilar joints includes tensile shear tests and metallographic analyses, depending on the energy per unit length.

  6. Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: laboratory investigation.

    PubMed

    Stipanicev, Marko; Turcu, Florin; Esnault, Loïc; Rosas, Omar; Basseguy, Régine; Sztyler, Magdalena; Beech, Iwona B

    2014-06-01

    Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -80045), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.

  7. An investigation of reheat cracking in the weld heat affected zone of type 347 stainless steel

    NASA Astrophysics Data System (ADS)

    Phung-On, Isaratat

    2007-12-01

    Reheat cracking has been a persistent problem for welding of many alloys such as the stabilized stainless steels: Types 321 and 347 as well as Cr-Mo-V steels. Similar problem occurs in Ni-base superalloys termed "strain-age cracking". Cracking occurs during the post weld heat treatment. The HAZ is the most susceptible area due to metallurgical reactions in solid state during both heating and cooling thermal cycle. Many investigations have been conducted to understand the RHC mechanism. There is still no comprehensive mechanism to explain its underlying mechanism. In this study, there were two proposed cracking mechanisms. The first is the formation of a PFZ resulting in local weakening and strain localization. The second is the creep-like grain boundary sliding that causes microvoid formation at the grain boundaries and the triple point junctions. Cracking occurs due to the coalescence of the microvoids that form. In this study, stabilized grade stainless steel, Type 347, was selected for investigation of reheat cracking mechanism due to the simplicity of its microstructure and understanding of its metallurgical behavior. The Gleeble(TM) 3800 system was employed due to its capability for precise control of both thermal and mechanical simulation. Cylindrical samples were subjected to thermal cycles for the HAZ simulation followed by PWHT as the reheat cracking test. "Susceptibility C-curves" were plotted as a function of PWHT temperatures and time to failure at applied stress levels of 70% and 80% yield strength. These C-curves show the possible relationship of the reheat cracking susceptibility and carbide precipitation behavior. To identify the mechanism, the sample shape was modified containing two flat surfaces at the center section. These flat surfaces were electro-polished and subjected to the HAZ simulation followed by the placement of the micro-indentation arrays. Then, the reheat cracking test was performed. The cracking mechanism was identified by tracing

  8. Theoretical Investigation of the Interfacial Reactions during Hot-Dip Galvanizing of Steel

    NASA Astrophysics Data System (ADS)

    Mandal, G. K.; Balasubramaniam, R.; Mehrotra, S. P.

    2009-03-01

    In the modern galvanizing line, as soon as the steel strip enters the aluminum-containing zinc bath, two reactions occur at the strip and the liquid-zinc alloy interface: (1) iron rapidly dissolves from the strip surface, raising the iron concentration in the liquid phase at the strip-liquid interface; and (2) aluminum forms a stable aluminum-iron intermetallic compound layer at the strip-coating interface due to its greater affinity toward iron. The main objective of this study is to develop a simple and realistic mathematical model for better understanding of the kinetics of galvanizing reactions at the strip and the liquid-zinc alloy interface. In the present study, a model is proposed to simulate the effect of various process parameters on iron dissolution in the bath, as well as, aluminum-rich inhibition layer formation at the substrate-coating interface. The transient-temperature profile of the immersed strip is predicted based on conductive and convective heat-transfer mechanisms. The inhibition-layer thickness at the substrate-coating interface is predicted by assuming the cooling path of the immersed strip consists of a series of isothermal holds of infinitesimal time-step. The influence of galvanizing reaction is assessed by considering nucleation and growth mechanisms at each hold time, which is used to estimate the total effect of the immersion time on the formation mechanism of the inhibition layer. The iron- dissolution model is developed based on well established principles of diffusion taking into consideration the area fraction covered by the intermetallic on the strip surface during formation of the inhibition layer. The model can be effectively used to monitor the dross formation in the bath by optimizing the process parameters. Theoretical predictions are compared with the findings of other researchers. Simulated results are in good agreement with the theoretical and experimental observation carried out by other investigators.

  9. An investigation on the hole quality during picosecond laser helical drilling of stainless steel 304

    NASA Astrophysics Data System (ADS)

    Zhang, Hongyu; Di, Jianke; Zhou, Ming; Yan, Yu; Wang, Rong

    2015-05-01

    Precision drilling with ultra-short pulse lasers (e.g., picosecond and femtosecond) has been advocated to significantly improve the quality of the micro-holes with reduced recast layer thickness and no heat-affected zone. However, a combination of high-power picosecond laser with helical drilling strategy in laser drilling has rarely been reported in previous studies. In the present study, a series of micro-holes with circular, triangular, rectangular, and rhombic shapes (diameter 0.6 mm) were manufactured on stainless steel 304 using a newly developed laser drilling system which incorporated a picosecond laser and a high-speed laser beam rotation apparatus into a five-axis positioning platform. The quality of the helical drilled holes, e.g., recast layer, micro-crack, circularity, and conicity, were evaluated using an optical microscope, an optical interferometer, and a scanning electron microscope. In addition, the microstructure of the samples was investigated following etching treatment. It was demonstrated that the entrance ends, the exit ends, and the side walls of the micro-holes were quite smooth without accumulation of spattering material and formation of recast layer and micro-crack. No tapering phenomenon was observed, and the circularity of the holes was fairly good. There was no distinctive difference with regard to the microstructure between the edges of the holes and the bulk material. Picosecond laser helical drilling can be an effective technique for manufacturing of micro-holes with very high quality. The development of high-power picosecond laser would promote picosecond laser drilling to be more industrial relevance in the future.

  10. Microstructural investigation of vintage pipeline steels highly susceptible to stress corrosion cracking

    NASA Astrophysics Data System (ADS)

    Torres, Monica

    The use of pipelines for the transmission of gas offers not only efficiency, but a number of economic advantages. Nevertheless, pipelines are subject to aggressive operating conditions and environments which can lead to in-service degradation [1] and thus to failures. These failures can have catastrophic consequences, such as environmental damage and loss of life [2]. One of the most dangerous threats to pipeline integrity is stress corrosion cracking (SCC). Despite the substantial progress that has been achieved in the field, due to the complex nature of this phenomenon there is still not a complete understanding of this form of external corrosion. This makes its detection and prevention a challenge and therefore a risk to pipeline integrity, and most importantly, to the safety of the population. SCC cracks are the result of the interaction between a corrosive environment, applied stresses, and a susceptible microstructure. To date, what defines a susceptible microstructure remains ambiguous, as SCC has been observed in a range of steel grades, microstructures, chemical composition, and grain sizes. Therefore, in order to be able to accurately predict and prevent this hazardous form of corrosion, it is imperative to advance our knowledge on the subject and gain a better understanding on the microstructural features of highly susceptible pipeline materials, especially in the subsurface zone where crack nucleation must take place. Therefore, a microstructural characterization of the region near the surface layer was carried-out utilizing TEM. TEM analysis revealed the dislocation character, ferrite morphology, and apparent carbide precipitation in some grain boundaries. Furthermore, light microscopy, SEM, and hardness testing were performed to expand our knowledge on the microscopical features of highly SCC susceptible service components. This investigation presents a new approach to SCC characterization, which exposed the sub-surface region microscopical

  11. Investigation of the sensitivity to EAC of steel T91 in contact with liquid LBE

    NASA Astrophysics Data System (ADS)

    Di Gabriele, F.; Doubková, A.; Hojná, A.

    2008-06-01

    The ferritic-martensitic steel T91 is one of the most promising material for application in the generation IV type reactors. However, there are critical issues, such as the susceptibility to damage of the steel in contact with the heavy liquid metals and their effect on the mechanical properties of structural materials. In this context, it was initiated a study of the boundary conditions, necessary to ascertain the sensitivity of the T91 to environmentally assisted cracking when loaded in contact with the liquid lead-bismuth eutectic. A series of tensile tests were carried out in a cell where the specimens were immersed in static LBE. Results showed that at high temperature the steel in contact with the liquid metal had a slight decrease of yield and UTS value and a marked increase in the elongation to rupture. However, at low temperature the elongation to rupture and the reduction of area decreased, indicating the sensitivity to EAC.

  12. An Experimental Investigation on Hardness and Microstructure of Heat Treated EN 9 Steel

    NASA Astrophysics Data System (ADS)

    Biswas, Palash; Kundu, Arnab; Mondal, Dhiraj

    2017-08-01

    In the modern engineering world, extensive research has led to the development of some special grades of steel, often suited for enhanced functions. EN 9 steel is one such grade, having major applications in power plants, automobile and aerospace industry. Different heat treatment processes are employed to achieve high hardness and high wear resistance, but machinability subsequently decreases. Existing literature is not sufficient to achieve a balance between hardness and machinability. The aim of this experimental work is to determine the hardness values and observe microstructural changes in EN9 steel, when it is subjected to annealing, normalizing and quenching. Finally, the effects of tempering after each of these heat treatments on hardness and microstructure have also been shown. It is seen that the tempering after normalizing the specimen achieved satisfactory results. The microstructure was also observed to be consisting of fine grains.

  13. Anodic Oxidation of Carbon Steel at High Current Densities and Investigation of Its Corrosion Behavior

    NASA Astrophysics Data System (ADS)

    Fattah-Alhosseini, Arash; Khan, Hamid Yazdani

    2017-02-01

    This work aims at studying the influence of high current densities on the anodization of carbon steel. Anodic protective coatings were prepared on carbon steel at current densities of 100, 125, and 150 A/dm2 followed by a final heat treatment. Coatings microstructures and morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the uncoated carbon steel substrate and the anodic coatings were evaluated in 3.5 wt pct NaCl solution through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The results showed that the anodic oxide coatings which were prepared at higher current densities had thicker coatings as a result of a higher anodic forming voltage. Therefore, the anodized coatings showed better anti-corrosion properties compared to those obtained at lower current densities and the base metal.

  14. An investigation of the plastic fracture of AISI 4340 and 18 nickel - 200 grade maraging steels

    NASA Technical Reports Server (NTRS)

    Cox, T. B.; Low, J. R., Jr.

    1974-01-01

    The mechanisms of plastic fracture (dimpled rupture) in high-purity and commercial 18 Ni, 200 grade maraging steels and quenched and tempered AISI 4340 steels have been studied. Plastic fracture takes place in the maraging alloys through void initiation by fracture of titanium carbo-nitride inclusions and the growth of these voids until impingement results in coalescence and final fracture. The fracture of AISI 4340 steel at a yield strength of 200 ksi occurs by nucleation and subsequent growth of voids formed by fracture of the interface between manganese sulfide inclusions and the matrix. The growth of these inclusion-nucleated voids is interrupted long before coalescence by impingement, by the formation of void sheets which connect neighboring sulfide-nucleated voids.

  15. Liquid Steel at Low Pressure: Experimental Investigation of a Downward Water Air Flow

    NASA Astrophysics Data System (ADS)

    Thumfart, Maria

    2016-07-01

    In the continuous casting of steel controlling the steel flow rate to the mould is critical because a well-defined flow field at the mould level is essential for a good quality of the cast product. The stopper rod is a commonly used device to control this flow rate. Agglomeration of solid material near the stopper rod can lead to a reduced cross section and thus to a decreased casting speed or even total blockage (“clogging”). The mechanisms causing clogging are still not fully understood. Single phase considerations of the flow in the region of the stopper rod result in a low or even negative pressure at the smallest cross section. This can cause degassing of dissolved gases from the melt, evaporation of alloys and entrainment of air through the porous refractory material. It can be shown that the degassing process in liquid steel is taking place mainly at the stopper rod tip and its surrounding. The steel flow around the stopper rod tip is highly turbulent. In addition refractory material has a low wettability to liquid steel. So the first step to understand the flow situation and transport phenomena which occur near the stopper is to understand the behaviour of this two phase (steel, gas) flow. To simulate the flow situation near the stopper rod tip, water experiments are conducted using a convergent divergent nozzle with three different wall materials and three different contact angles respectively. These experiments show the high impact of the wettability of the wall material on the actual flow structure at a constant gas flow rate.

  16. Coupled Multi-Electrode Investigation of Crevice Corrosion of AISI 316 Stainless Steel

    SciTech Connect

    F. Bocher; F. Presuel-Moreno; N.D. Budinasky; J.R. Scully

    2006-06-23

    Close packed coupled multi-electrodes arrays (MEA) simulating a planar electrode were used to measure the current evolution as a function of position during initiation and propagation of crevice corrosion of AISI 316 stainless steel. Scaling laws derived from polarization data enabled the use of rescaled crevices providing spatial resolution. Crevice corrosion of AISI 316 stainless steel in 0.6 M NaCl at 50 C was found to initiate close to the crevice mouth and to spread inwards with time. The local crevice current density increased dramatically over a short period to reach a limiting value.

  17. Electrochemical investigation on the corrosion inhibition of mild steel by Quinazoline Schiff base compounds in hydrochloric acid solution.

    PubMed

    Khan, Ghulamullah; Basirun, Wan Jeffrey; Kazi, Salim Newaz; Ahmed, Pervaiz; Magaji, Ladan; Ahmed, Syed Muzamil; Khan, Ghulam Mustafa; Rehman, Muhammad Abdur

    2017-09-15

    The inhibitory effect of two Schiff bases 3-(5-methoxy-2-hydroxybenzylideneamino)-2-(-5-methoxy-2-hydroxyphenyl)-2,3-dihydroquinazoline-4(1H)-one (MMDQ), and 3-(5-nitro-2-hydroxybenzylideneamino)-2(5-nitro-2-hydroxyphenyl)-2,3-dihydroquinazoline-4(1H)-one (NNDQ) on the corrosion of mild steel in 1M hydrochloric acid were studied using mass loss, potentiodynamic polarization technique and electrochemical impedance spectroscopy measurements at ambient temperature. The investigation results indicate that the Schiff Bases compounds with an average efficiency of 92% at 1.0mM of additive concentration have fairly effective inhibiting properties for mild steel in hydrochloric acid, and acts as mixed type inhibitor character. The inhibition efficiencies measured by all measurements show that the inhibition efficiencies increase with increase in inhibitor concentration. This reveals that the inhibitive mechanism of inhibitors were primarily due to adsorption on mild steel surface, and follow Langmuir adsorption isotherm. The temperature effect on the inhibition process in 1MHCl with the addition of investigated Schiff bases was studied at a temperature range of 30-60°C, and the activation parameters (Ea, ΔH and ΔS) were calculated to elaborate the corrosion mechanism. The differences in efficiency for two investigated inhibitors are associated with their chemical structures. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Atom-probe investigation of precipitation in 12% Cr steel weld metals

    NASA Astrophysics Data System (ADS)

    Cai, Guang-Jun; Lundin, Lars; Andrén, Hans-Olof; Svensson, Lars-Erik

    1994-03-01

    The microstructure of two types of 12% Cr steel weld metals, one with the composition of a common 12% Cr steel and the other with a higher nitrogen content, was studied using TEM (transmission electron microscopy) and APFIM (atom-probe field-ion microscopy) in post-weld heat-treated condition. The microstructure of the 12% Cr weld metals consisted of tempered martensite, retained δ-ferrite, an irregular low-dislocation α-ferrite and precipitates. Precipitates in the weld metals were dominantly M 23C 6 on different boundaries. Plate-like and fine cubic MN and M 2N were found inside the α-ferrite. APFIM analysis showed that M 23C 6 was almost a pure carbide and MN was almost a pure nitride. Carbon and nitrogen in the weld metals mainly existed in the precipitates. High nitrogen content did not change the composition of the precipitates, but increased the quantity of nitrides. Therefore, in the high nitrogen weld metal, the content of strong nitride-forming elements in the matrix decreased. These results are important in order to understand the strengthening mechanism of the high Cr steel weld metals, as well as of other high Cr heat-resistant steels.

  19. Failure Investigation for QP Steel Sheets under uniaxial and Equal-Biaxial Tension Conditions

    NASA Astrophysics Data System (ADS)

    Zou, Danqing; Li, Shuhui; He, Ji; Cui, Ronggao

    2016-08-01

    The Quenching and Partitioning (QP) steel sheet is new generation material to induce phase transformation for plasticity in forming vehicle parts. The phase transformation is strongly stress state dependent behavior in experiments, which should affect the failure timing and limit strain in forming processes. In this paper, Nakajima test with QP980 and DP1000 steel sheets under equal-biaxial loading condition is performed for failure behavior. X-ray diffraction (XRD) is adopted to obtain the volume fraction of retained austenite (fA). Digital Image Correlation (DIC) is used to record the surface strain field and its evolution during equal-biaxial tension deformation. The same level Dual Phase (DP) steel is also employed for the purpose of comparison. The results show that phase transformation in QP steel gives small impact on failure strain under equal biaxial tension condition which is contradicted with our understanding. It suggests that failure behavior under uniaxial tension of QP980 is strongly phase transformation dependent. But it shows almost independent under equal biaxial tension condition.

  20. In vitro electrochemical investigations of advanced stainless steels for applications as orthopaedic implants

    NASA Astrophysics Data System (ADS)

    Sivakumar, M.; Mudali, U. Kamachi; Rajeswari, S.

    1994-12-01

    Potentiodynamic anodic polarization experiments on advanced stainless steels (SS), such as nitrogenbearing type 316L and 317L SS, were carried out in Hank’s solution (8 g NaCl, 0.14 g CaCl2, 0.4 g KC1, 0.35 g NaHCO3, 1 g glucose, 0.1 g NaH2PO4, 0.1 g MgCl2, 0.06 g Na2HPO4 2H2O, 0.06 g MgSO4 7H2O/1000 mL) in order to assess the pitting and crevice corrosion resistance. The results showed a significant improvement in the pitting and crevice corrosion resistance than the commonly used type 316L stainless steel implant material. The corrosion resistance was higher in austenitic stainless steels containing higher amounts of nitrogen. The pit-protection potential for nitrogen-bearing stainless steels was more noble than the corrosion potential indicating the higher repassivation tendency of actively growing pits in these alloys. The accelerated leaching study conducted for the above alloys showed very little tendency for leaching of metal ions, such as iron, chromium, and nickel, at different impressed potentials. This may be due to the enrichment of nitrogen and molybdenum at the passive film and metal interface, which could have impeded the releasing of metal ions through passive film.

  1. Investigation of the Air-Argon-Steel-Slag Flow in an Industrial RH Reactor with VOF-DPM Coupled Model

    NASA Astrophysics Data System (ADS)

    Chen, Gujun; He, Shengping; Li, Yugang

    2017-08-01

    A coupled three-dimensional volume of fluid method-discrete phase model (VOF-DPM) is developed to investigate the air-argon-steel-slag flow in an industrial Rheinsahl-Heraeus (RH) reactor while considering the expansion of argon bubbles. The simulated results of mixing time and recirculation flow rate of molten steel, and the flow pattern and local velocity of water agree well with the measured results reported in the literature. Comparison of the results with and without consideration of the expansion of bubbles indicates that the expansion of bubbles has an enormous impact on the multiphase flow in the industrial RH reactor. The proposed mathematical model presents a more realistic free surface in the RH vacuum vessel.

  2. Investigation of Stainless Steel Corrosion in Ultrahigh-Purity Water and Steam Systems by Surface Analytical Techniques

    NASA Astrophysics Data System (ADS)

    Dong, Xia; Iacocca, Ronald G.; Bustard, Bethany L.; Kemp, Craig A. J.

    2010-02-01

    Stainless steel pipes with different degrees of rouging and a Teflon®-coated rupture disc with severe corrosion were thoroughly investigated by combining multiple surface analytical techniques. The surface roughness and iron oxide layer thickness increase with increasing rouge severity, and the chromium oxide layer coexists with the iron oxide layer in samples with various degrees of rouging. Unlike the rouging observed for stainless steel pipes, the fast degradation of the rupture disc was caused by a crevice corrosion environment created by perforations in the protective Teflon coating. This failure analysis clearly shows the highly corrosive nature of ultrapure water used in the manufacture of pharmaceutical products, and demonstrates some of the unexpected corrosion mechanisms that can be encountered in these environments.

  3. Experimental investigation of the influence of the stress state on the mechanical stability of austenite in multiphase steels

    NASA Astrophysics Data System (ADS)

    Furnémont, Q.; Delannay, F.; Jacques, P. J.

    2003-10-01

    The transformation-induced plasticity (TRIP) effect, i.e. the mechanically activated martensitic transformation of metastable austenite, has been proven for some years to contribute very effective to the deformation process in a large variety of iron-based alloys. In order to enlighten the influence of the stress triaxiality on the kinetics of the mechanically-induced martensitic transformation in TRIP-assisted multiphase steels, several specimens presenting austenite with different mechanical stabilities were strained under different stress states (pure uniaxial tension, uniaxial tension of notched and DENT specimens and stretching). It is shown that the stress triaxiality has a large effect on the mechanical stability of austenite dispersed in a multiphase microstructure and consequently on the mechanical properties of the investigated steels.

  4. 2D- and 3D SIMS investigations on hot-pressed steel powder HS 6-5-3-8.

    PubMed

    Rosner, M; Pöckl, G; Danninger, H; Hutter, H

    2002-10-01

    Processing of steel with powder metallurgical methods such as sintering or hot-pressing have proven to be a powerful tool for the production of industrial parts and for components in the automotive industry. Series of steel-powders (HS 6-5-3-8) produced by gas atomization has been hot-pressed in a graphite tube at temperatures from 820 degrees C to 1050 degrees C. The samples have been characterized with a Secondary Electron Microscope (SEM) due to their porosity and then investigated with 2D- and 3D- SIMS. The spatial distribution of the non-metallic impurities and the covering oxide layer of the single particles has been traced dependent to the pressing temperature. Powders pressed at temperatures higher than 880 degrees C exhibited different precipitation behavior of the impurities and an excessive loss of the covering oxide layer of the single powder particles.

  5. Magnetic properties of a highly neutron-irradiated nuclear reactor pressure vessel steel

    NASA Astrophysics Data System (ADS)

    Kobayashi, S.; Gillemot, F.; Horváth, Á.; Székely, R.

    2012-02-01

    We report results of minor B- H loop measurements on a highly neutron-irradiated A533B-type reactor pressure vessel steel. A minor-loop coefficient, which is a sensitive indicator of internal stress, changes with neutron fluence, but depends on relative orientation to the rolling direction in the low fluence regime. At a higher fluence of ˜10 × 10 23 m -2, on the other hand, an anomalous increase of the coefficient was detected irrespective of the orientation. The results were interpreted as due to competing irradiation mechanisms of the formation of Cu-rich precipitates, recovery process, and the formation of late-blooming Mn-Ni-Si-rich clusters.

  6. Experimental Investigation on Reduction Kinetics of Stainless Steel-Making Slag in Iron Bath Smelting Reduction

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Liu, Jienan; Yang, Yanfeng; Liu, Luming; Liu, Jiechao; Luo, Lijian; Ma, Yubao; Hong, Xin

    Reduction kinetics of stainless steel slag in iron bath smelting reduction was studied at the temperature of 1500°C ˜ 1650°C. It was concluded that the reduction process consisted of two parts. That is to say smelting reduction was controlled by stainless steel slag melting initially and by interface reaction later. In order to increase smelting reaction rate, the melting point of slag should be decreased at the first stage and adjust the liquidity of slag at later stage. Smelting reaction rate will be accelerated by means of optimize the slag content. The optimal reduction result that all most all of the chromium in slag been recovered was obtained in temperature was 1500°C, basicity of slag was 1.0˜1.2, the value of Al2O3+MgO was 25%.

  7. Investigation of dynamic dry friction between stainless steel and aluminium alloy

    NASA Astrophysics Data System (ADS)

    Keightley, Peter; Winter, Ron; Stirk, Stewart

    2009-06-01

    Previous workers studied dynamic friction by using an impacting copper plate to drive a tapered aluminium alloy plug into a matching hole in a stainless steel outer sheath. The velocity of the back surface of the plug was measured using velocity interferometry. We have performed experiments on a version of this basic configuration that has been enlarged so that the sliding surfaces remain in contact for a longer time than with the original configuration. By comparing our results with computer simulations we conclude that the frictional forces between the inner cone and the steel outer are initially high but decrease significantly as the sliding proceeds. This effect is assumed to result from thermal softening of the material at the sliding interface. The study is supported by metallography of the recovered components.

  8. Electrochemical investigations of Cr-Ni-Mo stainless steel used in urology

    NASA Astrophysics Data System (ADS)

    Przondziono, J.; Walke, W.

    2011-05-01

    The influence of chemical passivation process on physical and chemical characteristics of samples made of X2CrNiMo 17-7-2 steel with differentiated hardening, in the solution simulating the environment of human urine was analysed in the study. Wire obtained in cold drawing process is used for the production of stents and appliances in urological treatment. Proper roughness of the surface was obtained through mechanical working - grinding (Ra = 0,40 μn) and electrochemical polishing (Ra = 0,12 μn). Chemical passivation process was carried out in 40% solution of HN03 within 60 minutes in the temperature of 65°C. The tests of corrosion resistance were made on the ground of registered anodic polarisation curves and Stern method. For evaluation of phenomena occurring on the surface of tested steel, electrochemical impedance spectroscopy (EIS) was applied.

  9. An Investigation on Machinability during Turning Hardened Steel in Dry Condition

    NASA Astrophysics Data System (ADS)

    Mondal, Krishnendu; Das, Santanu

    2017-05-01

    Turning of hard materials is usually experienced to have poor machinability. However, to have high productivity, it is desired to go in for turning of hard materials. In the present work, turning of hardened AISI 4340 steel is explored to judge machining performance of plain and groove-type chip breaking TiC coated carbide inserts under dry conditions under different cutting velocity and feed. AISI 4340 steel is considered to be hard and difficult-to-machine. Hence, machinability of this tool inserts and workpiece material combine under different conditions is explored. It is found out that at a cutting velocity of 272 m/min and feed of 0.1 mm/rev, better machinability has been achieved with the wide groove tool insert than that with the other tool inserts used in this work, and hence, may be recommended.

  10. An investigation of laser cutting quality of 22MnB5 ultra high strength steel using response surface methodology

    NASA Astrophysics Data System (ADS)

    Tahir, Abdul Fattah Mohd; Aqida, Syarifah Nur

    2017-07-01

    In hot press forming, changes of mechanical properties in boron steel blanks have been a setback in trimming the final shape components. This paper presents investigation of kerf width and heat affected zone (HAZ) of ultra high strength 22MnB5 steel cutting. Sample cutting was conducted using a 4 kW Carbon Dioxide (CO2) laser machine with 10.6 μm wavelength with the laser spot size of 0.2 mm. A response surface methodology (RSM) using three level Box-Behnken design of experiment was developed with three factors of peak power, cutting speed and duty cycle. The parameters were optimised for minimum kerf width and HAZ formation. Optical evaluation using MITUTOYO TM 505 were conducted to measure the kerf width and HAZ region. From the findings, laser duty cycle was crucial to determine cutting quality of ultra-high strength steel; followed by cutting speed and laser power. Meanwhile, low power intensity with continuous wave contributes the narrowest kerf width formation and least HAZ region.

  11. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    NASA Astrophysics Data System (ADS)

    Timma, Christian; Lostak, Thomas; Janssen, Stella; Flock, Jörg; Mayer, Christian

    2016-12-01

    Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH4)2SO4) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH4)2Zn(SO4)2 * xH2O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  12. Investigation of black spots and other blemishes inside small stainless steel pressure vessels

    SciTech Connect

    Heiple, C.R.; Doyle, J.H.; Burgardt, P.

    1990-08-14

    Black spots and other blemishes were found on the inside surface of small stainless steel pressure vessels by borescope inspection. Most of the black spots originated from pyrolysis of lint contaminating the interior surface of these parts prior to welding. The lint originated from cotton gloves used to handle parts and from cotton gauze used to clean the parts. Pyrolysis of other hydrocarbons can also create black spots. 34 figs.

  13. An Investigation of a Maraging Steel with Lower Ni and Co Contents,

    DTIC Science & Technology

    1979-04-10

    lDCYP)-0256-79 EDITED TRANSLATION TD -ID(RS)T-0256-79 10 April 1979 AN INVESTIOATION OF A MARAGINO STEEL WITH LOWER Ni AND Co CONTENTS By: Tsai Chi-kung...oo’ieisiernblo aitW (,if Wk- ni TI Is added to mairn- bwg steeafl so as to gwiarnintfie a relitonor -ront -tit~nt. of’ hexagonal. SCon -p eked 1 555,s ’IIm

  14. Investigation of the microbial communities colonizing prepainted steel used for roofing and walling.

    PubMed

    Huynh, Tran T; Jamil, Ili; Pianegonda, Nicole A; Blanksby, Stephen J; Barker, Philip J; Manefield, Mike; Rice, Scott A

    2017-04-01

    Microbial colonization of prepainted steel, commonly used in roofing applications, impacts their aesthetics, durability, and functionality. Understanding the relevant organisms and the mechanisms by which colonization occurs would provide valuable information that can be subsequently used to design fouling prevention strategies. Here, next-generation sequencing and microbial community finger printing (T-RFLP) were used to study the community composition of microbes colonizing prepainted steel roofing materials at Burrawang, Australia and Kapar, Malaysia over a 52-week period. Community diversity was low and was dominated by Bacillus spp., cyanobacteria, actinobacteria, Cladosporium sp., Epicoccum nigrum, and Teratosphaeriaceae sp. Cultivation-based methods isolated approximately 20 different fungi and bacteria, some of which, such as E. nigrum and Cladosporium sp., were represented in the community sequence data. Fluorescence in situ hybridization imaging showed that fungi were the most dominant organisms present. Analysis of the sequence and T-RFLP data indicated that the microbial communities differed significantly between locations and changed significantly over time. The study demonstrates the utility of molecular ecology tools to identify and characterize microbial communities associated with the fouling of painted steel surfaces and ultimately can enable the targeted development of control strategies based on the dominant species responsible for fouling. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  15. A theoretical investigation of orientation relationships and transformation strains in steels.

    PubMed

    Koumatos, K; Muehlemann, A

    2017-03-01

    The identification of orientation relationships (ORs) plays a crucial role in the understanding of solid phase transformations. In steels, the most common models of ORs are the ones by Nishiyama-Wassermann (NW) and Kurdjumov-Sachs (KS). The defining feature of these and other OR models is the matching of directions and planes in the parent face-centred cubic γ phase to ones in the product body-centred cubic/tetragonal α/α' phase. In this article a novel method that identifies transformation strains with ORs is introduced and used to develop a new strain-based approach to phase-transformation models in steels. Using this approach, it is shown that the transformation strains that leave a close-packed plane in the γ phase and a close-packed direction within that plane unrotated are precisely those giving rise to the NW and KS ORs when a cubic product phase is considered. Further, it is outlined how, by choosing different pairs of unrotated planes and directions, other common ORs such as the ones by Pitsch and Greninger-Troiano can be derived. One of the advantages of our approach is that it leads to a natural generalization of the NW, KS and other ORs for different ratios of tetragonality r of the product body-centred tetragonal α' phase. These generalized ORs predict a sharpening of the transformation textures with increasing tetragonality and are thus in qualitative agreement with experiments on steels with varying alloy concentration.

  16. Investigation on the cold rolling and structuring of cold sprayed copper-coated steel sheets

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Wiesner, S.; Gerdt, L.; Senge, S.; Hirt, G.

    2017-03-01

    A current driving force of research is lightweight design. One of the approaches to reduce the weight of a component without causing an overall stiffness decrease is the use of multi-material components. One of the main challenges of this approach is the low bonding strength between different materials. Focusing on steel-aluminum multi-material components, thermally sprayed copper coatings can come into use as a bonding agent between steel sheets and high pressure die cast aluminum to improve the bonding strength. This paper presents a combination of cold gas spraying of copper coatings and their subsequent structuring by rolling as surface pretreatment method of the steel inserts. Therefore, flat rolling experiments are performed with samples in “as sprayed” and heat treated conditions to determine the influence of the rolling process on the bond strength and the formability of the coating. Furthermore, the influence of the rolling on the roughness and the hardness of the coating was examined. In the next step, the coated surface was structured, to create a surface topology suited for a form closure connection in a subsequent high-pressure die casting process. No cracks were observed after the cold rolling process with a thickness reduction of up to ε = 14 % for heat treated samples. Structuring of heat treated samples could be realized without delamination and cracking.

  17. Nondestructive characterization of embrittlement in reactor pressure vessel steels -- A feasibility study

    SciTech Connect

    McHenry, H.I.; Alers, G.A.

    1998-03-01

    The Nuclear Regulatory Commission recently initiated a study by NIST to assess the feasibility of using physical-property measurements for evaluating radiation embrittlement in reactor pressure vessel (RPV) steels. Ultrasonic and magnetic measurements provide the most promising approaches for nondestructive characterization of RPV steels because elastic waves and magnetic fields can sense the microstructural changes that embrittle materials. The microstructural changes of particular interest are copper precipitation hardening, which is the likely cause of radiation embrittlement in RPV steels, and the loss of dislocation mobility that is an attribute of the ductile-to-brittle transition. Measurements were made on a 1% copper steel, ASTM grade A710, in the annealed, peak-aged and overaged conditions, and on an RPV steel, ASTM grade A533B. Nonlinear ultrasonic and micromagnetic techniques were the most promising measures of precipitation hardening. Ultrasonic velocity measurements and the magnetic properties associated with hysteresis-loop measurements were not particularly sensitive to either precipitation hardening or the ductile-to-brittle transition. Measurements of internal friction using trapped ultrasonic resonance modes detected energy losses due to the motion of pinned dislocations; however, the ultrasonic attenuation associated with these measurements was small compared to the attenuation caused by beam spreading that would occur in conventional ultrasonic testing of RPVs.

  18. Numerical and experimental investigations on an extrusion process for a newly developed ultra-high-carbon lightweight steel for the automotive industry

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Bouguecha, A.; Bonk, C.; Yarcu, D.; Kazhai, M.

    2017-02-01

    In this study the material flow of a newly developed ultra-high-carbon lightweight steel (uhc-steel) with a high amount of aluminum was investigated in an extrusion process. Cylinder compression tests were performed for material characterization and frictional behaviour was determined by using ring compression tests. Numerical simulations were carried to determine the optimal die geometry as well as to calculate the process loads and dominated stresses in the die occurring during the process. Based on the numerical results, an extrusion process was designed and implemented. Experiments showed that the uhc-steel can be formed by extrusion however it is associated with a high wear rate.

  19. Investigation of residual stresses in a multipass weld in 1 in. stainless steel plate

    NASA Astrophysics Data System (ADS)

    Spooner, S.; Fernandezbaca, J. A.; David, S. A.; Hubbard, C. R.; Holden, T. M.; Root, J. H.

    Residual stresses and strains were measured in two welded 25-mm thick plates of type 304 stainless steel by the neutron diffraction technique. The filler metal was type 308 stainless steel and the weld zone had a two phase microstructure in which the austenitic phase lattice parameter differs from the base metal. In these circumstances strain-free samples were taken from the weld zone area for analysis of the lattice parameters and ferrite content using neutron powder diffraction. Corrections for lattice parameter variation were applied permitting the calculation of residual strains and stresses in weld zone, heat affected zone (HAZ), and base metal. One of the two welds was examined without stress relief and the other was given a stress relief treatment consisting of vibration at a frequency below the resonant condition during welding. In both plates the largest residual stress component (longitudinal) is found in the fusion zone near the boundary between the weld zone and the heat affected zone. This longitudinal component is 400 +/- 50 MPa in tension. The normal stresses are generally close to zero although large fluctuations are found in the weld zone. The transverse stresses are as high as 200 MPa in the weld zone and decrease to 50 MPa +/- 40 MPa. The lattice parameter variation was equivalent to 5 x 10(exp -4) compressive strain and the ferrite content approached 9 percent at the center of the weld zone. Variations in residual stresses with thickness through the base metal plate were small. The treated plate and untreated plate showed nearly identical patterns of stress distribution. Differences in the measured stresses between vibratory-stress-relief treated and untreated plates fall within error bars of the stress determination in these particular 25 mm thick 300-type stainless steel plates.

  20. Experimental Investigations on Fusion Cutting Stainless Steel with Fiber and CO2 Laser Beams

    NASA Astrophysics Data System (ADS)

    Stelzer, S.; Mahrle, A.; Wetzig, A.; Beyer, E.

    First results of an experimental study on inert-gas fusion cutting stainless steel with different types of laser are presented. In particular, the cutting capabilities of a fiber and a CO2 laser beam with similar Rayleigh length have been compared as a function of material thickness with respect to achievable maximum cutting speed, cut edge surface roughness and cut kerf geometry. The most interesting finding achieved so far concerns the observation that the cut kerfs are nearly identical in size but differ qualitatively in shape for both laser teypes.

  1. Investigation of coatings of austenitic steels produced by supersonic laser deposition

    NASA Astrophysics Data System (ADS)

    Gorunov, A. I.; Gilmutdinov, A. Kh.

    2017-02-01

    The structure and properties of stainless austenitic steel coatings obtained by the supersonic laser deposition are studied in the paper. Implantation of the powder particles into the substrate surface and simultaneous plastic deformation at partial melting improved the mechanical properties of the coatings - tensile strength limit was 650 MPa and adhesion strength was 105 MPa. It was shown that insufficient laser power leads to disruption of the deposition process stability and coating cracking. Surface temperature increase caused by laser heating above 1300 °C resulted in coating melting. The X-ray analysis showed that radiation intensifies the cold spray process and does not cause changes in the austenitic base structure.

  2. Experimental Investigation of the Capacity of Steel Fibers to Ensure the Structural Integrity of Reinforced Concrete Specimens Coated with CFRP Sheets

    NASA Astrophysics Data System (ADS)

    Gribniak, V.; Arnautov, A. K.; Norkus, A.; Tamulenas, V.; Gudonis, E.; Sokolov, A.

    2016-07-01

    The capacity of steel fibers to ensure the structural integrity of reinforced concrete specimens coated with CFRP sheets was investigated. Test data for four ties and eight beams reinforced with steel or glass-FRP bars are presented. Experiments showed that the fibers significantly increased the cracking resistance and altered the failure character from the splitting of concrete to the debonding of the external sheets, which noticeably increased the load-carrying capacity of the strengthened specimens.

  3. Investigation of a fatigue failure in a stainless steel femoral plate.

    PubMed

    Marcomini, J B; Baptista, C A R P; Pascon, J P; Teixeira, R L; Reis, F P

    2014-10-01

    Surgical implants are exposed to severe working conditions and therefore a wide range of failure mechanisms may occur, including fatigue, corrosion, wear, fretting and combinations of them. The mechanical failures of metallic implants may also be influenced by several other factors, including the design, material, manufacturing, installation, postoperative complications and misuse. An 83-year-old patient suffered an oblique femoral shaft fracture due to a fall at home. A stainless steel locking compression plate (LCP) employed in the fracture reduction failed after four months and was sent back to the producer. A second LCP of the same type was implanted and also failed after six months. A failure analysis of the second femoral LCP is performed in this paper. The results demonstrate that poor material quality was decisive to the failure. The chemical analysis revealed a high P content in the steel, which is not in accordance to the standards. A combination of factors lead to LCP fracture and these include: brittle crack initiation due to phosphorus, segregation at grain boundaries, crack propagation due to cyclic loading and final fast fracture favored by the loss of ductility due to cold work.

  4. An investigation of phase transformation and crystallinity in laser surface modified H13 steel

    NASA Astrophysics Data System (ADS)

    Aqida, S. N.; Brabazon, D.; Naher, S.

    2013-03-01

    This paper presents a laser surface modification process of AISI H13 tool steel using 0.09, 0.2 and 0.4 mm size of laser spot with an aim to increase hardness properties. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 tool steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, overlap percentage and pulse repetition frequency (PRF). X-ray diffraction analysis (XRD) was conducted to measure crystallinity of the laser-modified surface. X-ray diffraction patterns of the samples were recorded using a Bruker D8 XRD system with Cu K α ( λ=1.5405 Å) radiation. The diffraction patterns were recorded in the 2 θ range of 20 to 80°. The hardness properties were tested at 981 mN force. The laser-modified surface exhibited reduced crystallinity compared to the un-processed samples. The presence of martensitic phase was detected in the samples processed using 0.4 mm spot size. Though there was reduced crystallinity, a high hardness was measured in the laser-modified surface. Hardness was increased more than 2.5 times compared to the as-received samples. These findings reveal the phase source of the hardening mechanism and grain composition in the laser-modified surface.

  5. Investigation of thermal spray coatings on austenitic stainless steel substrate to enhance corrosion protection

    NASA Astrophysics Data System (ADS)

    Rogers, Daniel M.

    The research is aimed to evaluate thermal spray coatings to address material issues in supercritical and ultra-supercritical Rankine cycles. The primary purpose of the research is to test, evaluate, and eventually implement a coating to improve corrosion resistance and increase efficiency of coal fired power plants. The research is performed as part of a comprehensive project to evaluate the ability of titanium, titanium carbide, or titanium diboride powders to provide fireside corrosion resistance in supercritical and ultra-supercritical steam boilers, specifically, coal driven boilers in Illinois that must utilize high sulfur and high chlorine content coal. [1] The powder coatings that were tested are nano-sized titanium carbide (TiC) and titanium di-boride (TiB2) powders that were synthesized by a patented process at Southern Illinois University. The powders were then sent to Gas Technology Institute in Chicago to coat steel coupons by HVOF (High Velocity Oxy-Fuel) thermal spray technique. The powders were coated on an austenitic 304H stainless steel substrate which is commonly found in high temperature boilers, pipelines, and heat exchangers. The samples then went through various tests for various lengths of time under subcritical, supercritical, and ultra-supercritical conditions. The samples were examined using a scanning electron microscope and x-ray diffraction techniques to study microstructural changes and then determined which coating performed best.

  6. Experimental investigation on geometrical aspects of micro-plasma deposited tool steel for repair applications

    NASA Astrophysics Data System (ADS)

    Jhavar, S.; Paul, C. P.; Jain, N. K.

    2014-08-01

    Recent advancement in direct material deposition processes found wide applications in rapid prototyping, manufacturing and tooling industry. Micro-plasma deposition is one of the recent developments in this domain. This paper reports the deployment of newly integrated micro-plasma deposition system for the deposition of AISI P-20 tool steel on the AISI P20 tool steel substrate. A number of test tracks for single track deposition were deposited at the various combination of processing parameters. The sets of parameters yielding good deposits were selected to deposit overlap tracks. The geometry of single and overlapped tracks was evaluated to understand the parametric dependence. The study indicates that the aspect ratio of track geometry (ratio of width to height of track) is dependent on the processing parameters and the discharge current is identified as the most dominating parameters (contribution = 44%), followed by scan speed (contribution = 26.68%) and wire feed rate (contribution = 26.98%) with almost same effect. The microscopic study of the deposits indicates that the material deposited at the optimum processing parameters is free from surface and bulk defects. The estimated material properties are found to be at par with conventional processed material. This feasibility study proved that the micro-plasma deposition can be used for the generation of surfaces and multi-featured material deposition. It paved a way for the application of the process in die/mold repairs.

  7. Investigation into Microstructures of Maraging Steel 250 Weldments and Effect of Post-Weld Heat Treatments

    NASA Astrophysics Data System (ADS)

    Tariq, Fawad; Baloch, Rasheed Ahmed; Ahmed, Bilal; Naz, Nausheen

    2010-03-01

    This study was undertaken to gain a better understanding of microstructures obtained by multipass gas tungsten arc welding in maraging steel grade 250. Metallography and microhardness measurements were carried out on sheet and welded joints in as-welded and post-weld aged conditions. It was found that there was a significant amount of reverted austenite formed on cell boundaries of weld metal after aging at 758-823 K for 3-5 h, and was stable at room temperature. Aging at higher temperatures led to an increase in the continuous network of patchy austenite along the cell boundaries. The reason for the above, in our opinion, is the concentrational heterogeneity which characterizes the microstructure of maraging steel welds. No reverted austenite was observed in as-welded specimens. Solution annealing at 1093 K for 1 h did not completely eliminate the chemical heterogeneity associated with weld structures. However, homogenizing at 1373 K produced homogenous structure that on subsequent aging produces austenite-free lath martensitic structure.

  8. Investigation on Hydrogen-Induced Delayed Fracture of Cold-Rolled DP980 Steels

    NASA Astrophysics Data System (ADS)

    Han, Yun; Chen, Liang; Kuang, Shuang; Xie, Chunqian

    2017-05-01

    In this study, the phenomenon of hydrogen-induced delayed fracture of two cold-rolled DP980 steels with different chemical compositions was studied. The results show that the microstructure of both steels is composed of ferrite matrix, martensite-austenite islands and small amount of bainite. DP980-1 having higher contents of C and Si exhibits higher tensile strength, lower yield strength and higher elongation in comparison with DP980-2 having lower contents of C and Si. According to the results of slow strain rate tensile tests, the tensile strength of DP980-1 after hydrogen charging is reduced by 20.8%, while it is just 5.4% for DP980-2. Moreover, very fine dimples can still be observed in the fracture surface of DP980-2 after hydrogen charging, which indicates a good ductile. The main reasons leading to the better delayed fracture resistance of DP980-2 are the lower volume fraction of martensite-austenite islands, lower content of diffusible hydrogen and the grain refinement effects.

  9. Investigation of Synthesized Sulfonated Melamine Formaldehyde as a Novel Corrosion Inhibitor for Mild Steel in Saline Environment

    NASA Astrophysics Data System (ADS)

    Sharifi, Zahra; Pakshir, Mahmoud; Mohamadi, Somayeh

    2015-02-01

    A water soluble compound named sulfonated melamine formaldehyde (SMF) was synthesized and its corrosion inhibition behavior was studied for carbon steel in 3.5% NaCl solution by polarization measurements and electrochemical impedance spectroscopy (EIS). SMF was characterized with hydrogen nuclear magnetic resonance spectroscopy and then its physical properties and corrosion prevention efficiencies were investigated. The corrosion behavior of SMF was found to be dependent strongly on the electric nature of functional groups which are present in its structure. The decrease in ( i corr) and the increase in inhibition efficiency (% IE) with increasing the SMF concentrations proves that it protects C-steel in 3.5% NaCl solution from being corroded and Nyquist diagrams indicate that increasing charge transfer resistance is associated with a decrease in the capacitance and increase in the percentage inhibition efficiency. The decrease in capacitance values could be attributed to the adsorption of the inhibitor molecules at the metal surface by increasing the concentration of inhibitor in the solution the inhibition efficiency increased and the best inhibition was obtained at 1000 ppm inhibitor concentration. The scanning electron microscope was used to investigate the surface morphology of specimens in the absence and presence of inhibitor compound.

  10. Hall versus conventional stainless steel crown techniques: in vitro investigation of marginal fit and microleakage using three different luting agents.

    PubMed

    Erdemci, Zeynep Yalçınkaya; Cehreli, S Burçak; Tirali, R Ebru

    2014-01-01

    This study's purpose was to investigate microleakage and marginal discrepancies in stainless steel crowns (SSCs) placed using conventional and Hall techniques and cemented with three different luting agents. Seventy-eight human primary maxillary second molars were randomly assigned to two groups (N=39), and SSCs were applied either with the Hall or conventional technique. These two groups were further subgrouped according to the material used for crown cementation (N=13 per group). Two specimens in each group were processed for scanning electron microscopy investigation. The extent of microleakage and marginal fit was quantified in millimeters on digitally photographed sections using image analysis software. The data were compared with a two-way independent and a two-way mixed analysis of variance (P=.05). The scores in the Hall group were significantly worse than those in the conventional technique group (P<.05). In both groups, resin cement displayed the lowest extent of microleakage, followed by glass ionomer and polycarboxylate cements (P<.05). Stainless steel crowns applied using the Hall technique displayed higher microleakage scores than those applied using the conventional technique, regardless of the cementation material. When the interaction of the material and technique was assessed, resin cement presented as the best choice for minimizing microleakage in both techniques.

  11. An investigation into the effects of conventional heat treatments on mechanical characteristics of new hot working tool steel

    NASA Astrophysics Data System (ADS)

    Fares, M. L.; Athmani, M.; Khelfaoui, Y.; Khettache, A.

    2012-02-01

    The effects of conventional heat treatments, i.e. quenching and tempering, on the mechanical characteristics of non standard hot work tool steel, close to either AISI-H11/H13 are investigated. The major elemental composition differences are in carbon, silicon and vanadium. The objective of the carried heat treatments is to obtain an efficient tool performance in terms of hardness, wear resistance and mechanical strength. Experimental results allow an explanation of the surface properties depending mainly on both chemical composition and optimised preheating parameters. After austenitizing at 1050 °C for 15 min, the as-quenched steel in oil bath exhibited the fully martensitic structure (without bainite) connected to a small fraction of retained austenite and complex carbides mainly of M23C6 type. Twice tempering at 500 °C and 600 °C resulted in initiating the precipitation processes and the secondary hardness effect. As a result, carbide content amounted to 3% while the retained austenite content decreased to 0%. Accordingly, the required mechanical properties in terms of hardness and wear are fulfilled and are adequately favourable in handling both shocks and pressures for the expected tool life. Induced microstructures are revealed using optical and scanning electron microscopes. Phase compositions are assessed by means of X-ray diffraction technique while mechanical characteristics are investigated based on hardness and abrasive wear standard tests.

  12. Investigation of radiation damage in VVER-440 reactor vessel steels by SANS

    NASA Astrophysics Data System (ADS)

    Šaroun, Jan; Kočík, Jan; Strunz, Pavel

    2004-07-01

    The effect of neutron irradiation on the microstructure of VVER-440 type reactor pressure vessel steels was studied by small-angle neutron scattering (SANS). The SANS spectra were fitted by a model of non-ferromagnetic particles in saturated ferromagnetic matrix, which permitted us to evaluate apparent volume fractions (weighted by scattering contrast), size distributions and mean ratio of magnetic to total scattering cross-sections for small (R<3nm) irradiation-induced precipitates. Close correlation between the apparent volume fraction of the damaged domains and ductility transition temperature was observed. Differences in the volume fractions obtained from magnetic and nuclear scattering indicated that chemical composition varied with increasing fluence and could be explained by increasing concentrations of solute atoms in the damaged domains. This coarsening effect is also manifested on the size distributions by slight growth of mean domain radius.

  13. Investigation Of Adhesion Formation In New Stainless Steel Trim Spring Operated Pressure Relief Valves

    SciTech Connect

    Gross, Robert E.; Bukowski, Julia V.; Goble, William M.

    2013-04-16

    Examination of proof test data for new (not previously installed) stainless steel (SS) trim spring operated pressure relief valves (SOPRV) reveals that adhesions form between the seat and disc in about 46% of all such SOPRV. The forces needed to overcome these adhesions can be sufficiently large to cause the SOPRV to fail its proof test (FPT) prior to installation. Furthermore, a significant percentage of SOPRV which are found to FPT are also found to ''fail to open'' (FTO) meaning they would not relief excess pressure in the event of an overpressure event. The cases where adhesions result in FTO or FPT appear to be confined to SOPRV with diameters < 1 in and set pressures < 150 psig and the FTO are estimated to occur in 0.31% to 2.00% of this subpopulation of SS trim SOPRV. The reliability and safety implications of these finding for end-users who do not perform pre-installation testing of SOPRV are discussed.

  14. An investigation of the aseptic loosening of an AISI 316L stainless steel hip prosthesis.

    PubMed

    Godec, Matjaz; Kocijan, Aleksandra; Dolinar, Drago; Mandrino, Djordje; Jenko, Monika; Antolic, Vane

    2010-08-01

    The total replacement of joints by the implantation of permanently indwelling prosthetic components has been one of the major successes of modern surgery in terms of relieving pain and correcting deformity. However, the aseptic loosening of a prosthetic-joint component is the most common reason for joint-revision surgery. Furthermore, it is thought that wear particles are one of the major contributors to the development and perpetuation of aseptic loosening. The aim of the present study was to identify the factors related to the aseptic loosening of an AISI 316L stainless steel total hip prosthesis. The stem was evaluated by x-ray photoelectron spectroscopy, with polished and rough regions being analyzed in order to establish the differences in the chemical compositions of both regions. Specific areas were examined using scanning electron microscopy with energy dispersive x-ray spectroscopy and light microscopy.

  15. Investigation of the efficiency process during CO2 laser welding of low-alloyed steels

    NASA Astrophysics Data System (ADS)

    Petrov, Peter; Apostolova, Tzveta

    2008-10-01

    This paper reports results from the theoretical and experimental study of the energy transfer during CO2 laser beam welding of 10 mm low-alloyed steels square butt joints. The laser beam power and the welding speed are varied systematically from 9 kW to 32 kW and from 1 m/min to 5 m/min, respectively. The observed weld depth penetration is up to 10 mm and the width of weld seams is between 0.8 and 1.25 mm. The joining efficiency during the laser welding was in the range of 11.8 to 32 mm2/kJ. Melting efficiency is determined from the measured welding seams cross section for a specified laser power and travel speed. Theoretically, predicted values of melting efficiency are calculated using Rosenthal's and Rycalin moving heat sources equation in 2D (line source).

  16. Investigation of laser metal deposited Alloy 718 onto an EN 1.4401 stainless steel substrate

    NASA Astrophysics Data System (ADS)

    Segerstark, Andreas; Andersson, Joel; Svensson, Lars-Erik

    2017-12-01

    This paper focuses on how process parameters affect the deposition of Alloy 718 onto an EN 1.4401 stainless steel substrate in terms of secondary phase formation, dilution and hardness. A columnar solidification structure with elongated grains growing in the direction normal to the substrate was observed for all parameters. In the interdendritic regions, phases with a high content of Niobium were identified. Scanning Electron Microscopy imaging and Energy Dispersive Spectroscopy measurements revealed these phases to most likely be Laves phase and Nb-carbides. Temperature measurements indicated no significant aging in the deposits. Considerable enrichment of iron was found in the initially deposited layers due to dilution from the substrate. The increased content of iron seemed to aid in forming constituents rich in niobium which, in turn, influenced the hardness. The highest mean hardness was noted in the sample with the lowest area fraction of Nb-rich constituents.

  17. Investigation on process parameters affecting blanking of AISI 1006 low carbon steel

    NASA Astrophysics Data System (ADS)

    D'Annibale, Antonello; El Mehtedi, Mohamad; Panaccio, Lorenzo; Di Ilio, Antoniomaria; Gabrielli, Filippo

    2016-10-01

    A blanking apparatus was designed and built in order to study the effects of the process parameters on blanking low carbon steel disks, with particular reference to the study of punch-die gap influence and Brozzo's damage criterion by keeping punch and die fillet radii constant. The goal of the shearing tests was to optimize the gap between punch and die, according to the material damage and the force curves obtained by experimental tests. By using a 2D axis-symmetry FE model, the authors studied a set of parameters in order to reduce damage. After studying the material damage by a first simulation series, a second series was carried out in order to evaluate the punch-die gap effects on force-stroke trend; good results in term of external surface finish were obtained in the geometry of the final workpiece.

  18. Investigation of AISI 441 Ferritic Stainless Steel and Development of Spinel Coatings for SOFC Interconnect Applications

    SciTech Connect

    Yang, Zhenguo; Xia, Guanguang; Wang, Chong M.; Nie, Zimin; Templeton, Joshua D.; Singh, Prabhakar; Stevenson, Jeffry W.

    2008-05-30

    As part of an effort to develop cost-effective ferritic stainless steel-based interconnects for solid oxide fuel cell (SOFC) stacks, both bare and spinel coated AISI 441 were studied in terms of metallurgical characteristics, oxidation behavior, and electrical performance. The conventional melt metallurgy used for the bulk alloy fabrication leads to significant processing cost reduction and the alloy chemistry with the presence of minor alloying additions of Nb and Ti facilitate the strengthening by precipitation and formation of Laves phase both inside grains and along grain boundaries during exposure in the intermediate SOFC operating temperature range. The Laves phase formed along the grain boundaries also ties up Si and prevents the formation of an insulating silica layer at the scale/metal interface during prolonged exposure. The substantial increase in ASR during long term oxidation due to oxide scale growth suggested the need for a conductive protection layer, which could also minimize Cr evaporation. In particular, Mn1.5Co1.5O4 based surface coatings on planar coupons drastically improved the electrical performance of the 441, yielding stable ASR values at 800ºC for over 5,000 hours. Ce-modified spinel coatings retained the advantages of the unmodified spinel coatings, and also appeared to alter the scale growth behavior beneath the coating, leading to a more adherent scale. The spinel protection layers appeared also to improve the surface stability of 441 against the anomalous oxidation that has been observed for ferritic stainless steels exposed to dual atmosphere conditions similar to SOFC interconnect environments. Hence, it is anticipated that, compared to unmodified spinel coatings, the Ce-modified coatings may lead to superior structural stability and electrical performance.

  19. Investigation of Austenite-to-Ferrite Transformation in Ultralow and Low-Carbon Steel Using High-Speed Quenching Dilatometry and Thermokinetic Simulation

    NASA Astrophysics Data System (ADS)

    Imtiaz, F.; Kozeschnik, E.

    2017-07-01

    The isothermal austenite decomposition kinetics is studied in 0.004 wt pct C ultralow carbon (ULC) and 0.11 wt pct C low-carbon (LC) steel using high-speed quenching dilatometry. Standard samples of these steels are heated to austenitization temperatures of 1223 K and 1373 K (950 °C and 1100 °C) and then quenched to testing temperatures between 1163 K and 933 K (890 °C and 660 °C). The measured and calculated austenite-to-ferrite phase fractions are compared with dilatation values to analyze the ferrite nucleation and growth conditions during austenite decomposition. Ferrite evolution profiles are assessed to investigate the underlying growth kinetics. The analysis in ULC steel shows regimes of partitionless, partitioning, and two-stage transformation kinetics. In contrast, LC steel shows only diffusion-controlled transformation kinetics. The experimental results are well reproduced with thermokinetic calculations, thus supporting our interpretation of governing mechanisms during transformation.

  20. Spectroscopic investigations of plasma nitriding processes: A comparative study using steel and carbon as active screen materials

    NASA Astrophysics Data System (ADS)

    Hamann, S.; Burlacov, I.; Spies, H.-J.; Biermann, H.; Röpcke, J.

    2017-04-01

    Low-pressure pulsed DC H2-N2 plasmas were investigated in the laboratory active screen plasma nitriding monitoring reactor, PLANIMOR, to compare the usage of two different active screen electrodes: (i) a steel screen with the additional usage of CH4 as carbon containing precursor in the feeding gas and (ii) a carbon screen without the usage of any additional gaseous carbon precursor. Applying the quantum cascade laser absorption spectroscopy, the evolution of the concentration of four stable molecular species, NH3, HCN, CH4, and C2H2, has been monitored. The concentrations were found to be in a range of 1012-1016 molecules cm-3. By analyzing the development of the molecular concentrations at variations of the screen plasma power, a similar behavior of the monitored reaction products has been found for both screen materials, with NH3 and HCN as the main reaction products. When using the carbon screen, the concentration of HCN and C2H2 was 30 and 70 times higher, respectively, compared to the usage of the steel screen with an admixture of 1% CH4. Considering the concentration of the three detected hydrocarbon reaction products, a combustion rate of the carbon screen of up to 69 mg h-1 has been found. The applied optical emission spectroscopy enabled the determination of the rotational temperature of the N2+ ion which has been in a range of 650-900 K increasing with the power in a similar way in the plasma of both screens. Also with power the ionic component of nitrogen molecules, represented by the N2+ (0-0) band of the first negative system, as well as the CN (0-0) band of the violet system increase strongly in relation to the intensity of the neutral nitrogen component, i.e., the N2 (0-0) band of the second positive system. In addition, steel samples have been treated with both the steel and the carbon screen resulting in a formation of a compound layer of up to 10 wt. % nitrogen and 10 wt. % carbon, respectively, depending on the screen material.

  1. X-ray and ion beam investigation of alumina coatings applied on DIN1.4914 martensitic steel

    NASA Astrophysics Data System (ADS)

    Iordanova, I.; Forcey, K. S.; Surtchev, M.

    2001-01-01

    An investigation has been carried out on the crystal structure and composition of the coatings applied by two processes: aluminising and RF-sputtering of alumina (Al 2O 3) on a high-chromium martensitic steel DIN1.4914. The investigation involved the use of two complementary techniques, namely, powder X-ray diffraction and ion beam methods. The results from the X-ray diffraction had been considered for the fit of the energetic spectra obtained by the Rutherford backscattering (RBS) of alpha particles and by O(d,p) nuclear reaction. By the combination of these two techniques, some new results about the structure parameters, depth profile composition and thickness of the coatings as a function of the technology of their application have been obtained.

  2. An Investigation of the Microstructure of an Intermetallic Layer in Welding Aluminum Alloys to Steel by MIG Process

    PubMed Central

    Nguyen, Quoc Manh; Huang, Shyh-Chour

    2015-01-01

    Butt joints of A5052 aluminum alloy and SS400 steel, with a new type of chamfered edge, are welded by means of metal inert gas welding and ER4043 Al-Si filler metal. The microhardness and microstructure of the joint are investigated. An intermetallic layer is found on the surface of the welding seam and SS400 steel sheet. The hardness of the intermetallic layer is examined using the Vickers hardness test. The average hardness values at the Intermetallic (IMC) layer zone and without the IMC layer zone were higher than that of the welding wire ER4043. The tensile strength test showed a fracture at the intermetallic layer when the tensile strength is 225.9 MPa. The tensile value test indicated the average of welds was equivalent to the 85% tensile strength of the A5052 aluminum alloy. The thickness of the intermetallic layers is non-uniform at different positions with the ranges from 1.95 to 5 μm. The quality of the butt joint is better if the intermetallic layer is minimized. The Si crystals which appeared at the welding seam, indicating that this element participated actively during the welding process, also contributed to the IMC layer’s formation. PMID:28793708

  3. An Investigation of the Microstructure of an Intermetallic Layer in Welding Aluminum Alloys to Steel by MIG Process.

    PubMed

    Nguyen, Quoc Manh; Huang, Shyh-Chour

    2015-12-02

    Butt joints of A5052 aluminum alloy and SS400 steel, with a new type of chamfered edge, are welded by means of metal inert gas welding and ER4043 Al-Si filler metal. The microhardness and microstructure of the joint are investigated. An intermetallic layer is found on the surface of the welding seam and SS400 steel sheet. The hardness of the intermetallic layer is examined using the Vickers hardness test. The average hardness values at the Intermetallic (IMC) layer zone and without the IMC layer zone were higher than that of the welding wire ER4043. The tensile strength test showed a fracture at the intermetallic layer when the tensile strength is 225.9 MPa. The tensile value test indicated the average of welds was equivalent to the 85% tensile strength of the A5052 aluminum alloy. The thickness of the intermetallic layers is non-uniform at different positions with the ranges from 1.95 to 5 μm. The quality of the butt joint is better if the intermetallic layer is minimized. The Si crystals which appeared at the welding seam, indicating that this element participated actively during the welding process, also contributed to the IMC layer's formation.

  4. Investigation of microstructural evolution under neutron irradiation in Eurofer97 steel by means of small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Coppola, R.; Lindau, R.; May, R. P.; Möslang, A.; Valli, M.

    2009-04-01

    Small-angle neutron scattering (SANS) has been utilized to investigate in Eurofer97 steel (9Cr, 0.01C, 1W, 0.2V Fe bal wt%) the microstructural effect of neutron irradiation at 300 °C up to a dose level of 8.4 dpa. For each irradiated sample an unirradiated reference was measured to distinguish as accurately as possible the actual effect of the neutron irradiation. The SANS measurements were carried out at the D22 diffractometer at the High-Flux Reactor of the Institut Max von Laue-Paul Langevin, Grenoble, France. Analysing separately the nuclear and magnetic SANS components obtained after subtraction of the reference from the irradiated sample it appears that the microstructural inhomogeneities produced under such irradiation conditions are non-magnetic ones, such as microvoids. Their size distributions are presented and compared with those previously obtained for the same steel irradiated at 2.5 dpa: with increasing the dose, the volume fraction is increased by a factor of 2 roughly, while the average size of these inhomogeneities remains nearly unchanged.

  5. Investigation of Clusters in Medium Carbon Secondary Hardening Ultra-high-strength Steel After Hardening and Aging Treatments

    NASA Astrophysics Data System (ADS)

    Veerababu, R.; Balamuralikrishnan, R.; Muraleedharan, K.; Srinivas, M.

    2015-06-01

    Clusters, containing between 10 and 1000 atoms, have been investigated in a martensitic secondary hardening ultra-high-strength steel austenitized at 1173 K (900 °C) for 1 hour and tempered at either 768 K or 783 K (495 °C or 510 °C) for 4 or 8 hours using 3D atom probe. The presence of clusters was unambiguously established by comparing the observed spatial distribution of the different alloying elements against the corresponding distribution expected for a random solid solution. Maximum separation envelope method has been used for delineating the clusters from the surrounding "matrix." Statistical analysis was used extensively for size and composition analyses of the clusters. The clusters were found to constitute a significant fraction accounting for between 1.14 and 2.53 vol pct of the microstructure. On the average, the clusters in the 783 K (510 °C) tempered sample were coarser by ~65 pct, with an average diameter of 2.26 nm, relative to the other samples. In all samples, about 85 to 90 pct of the clusters have size less than 2 nm. The percentage frequency histograms for carbon content of the clusters in 768 K and 783 K (495 °C and 510 °C) tempered samples revealed that the distribution shifts toward higher carbon content when the tempering temperature is higher. It is likely that the presence of these clusters exerts considerable influence on the strength and fracture toughness of the steel.

  6. Experimental investigation of the influence of Mo contained in stainless steel on Cs chemisorption behavior

    NASA Astrophysics Data System (ADS)

    Di Lemma, F. G.; Nakajima, K.; Yamashita, S.; Osaka, M.

    2017-02-01

    Chemisorption phenomena can affect fission products (FP) retention in a nuclear reactor vessel during a severe accident (SA). Detailed information on the FP chemisorbed deposits, especially for Cs, are important for a rational decommissioning of the reactor following a SA, as for the Fukushima Daiichi Power Station. Moreover the retention of Cs will influence the source term assessment and thus improved models for this phenomenon are needed in SA codes. This paper describes the influence on Cs chemisorption of molybdenum contained in stainless steel (SS) type 316. In our experiments it was observed that Cs-Mo deposits (CsFe(MoO4)3, Cs2MoO4) were formed together with CsFeSiO4, which is the predominant compound formed by chemisorption. The Cs-Mo deposits were found to revaporize from the SS sample at 1000 °C, and thus could contribute to the source term. On the other hand, CsFeSiO4 will be probably retained in the reactor during a SA due to its stability.

  7. The Investigation of Strain-Induced Martensite Reverse Transformation in AISI 304 Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cios, G.; Tokarski, T.; Żywczak, A.; Dziurka, R.; Stępień, M.; Gondek, Ł.; Marciszko, M.; Pawłowski, B.; Wieczerzak, K.; Bała, P.

    2017-07-01

    This paper presents a comprehensive study on the strain-induced martensitic transformation and reversion transformation of the strain-induced martensite in AISI 304 stainless steel using a number of complementary techniques such as dilatometry, calorimetry, magnetometry, and in-situ X-ray diffraction, coupled with high-resolution microstructural transmission Kikuchi diffraction analysis. Tensile deformation was applied at temperatures between room temperature and 213 K (-60 °C) in order to obtain a different volume fraction of strain-induced martensite (up to 70 pct). The volume fraction of the strain-induced martensite, measured by the magnetometric method, was correlated with the total elongation, hardness, and linear thermal expansion coefficient. The thermal expansion coefficient, as well as the hardness of the strain-induced martensitic phase was evaluated. The in-situ thermal treatment experiments showed unusual changes in the kinetics of the reverse transformation (α' → γ). The X-ray diffraction analysis revealed that the reverse transformation may be stress assisted—strains inherited from the martensitic transformation may increase its kinetics at the lower annealing temperature range. More importantly, the transmission Kikuchi diffraction measurements showed that the reverse transformation of the strain-induced martensite proceeds through a displacive, diffusionless mechanism, maintaining the Kurdjumov-Sachs crystallographic relationship between the martensite and the reverted austenite. This finding is in contradiction to the results reported by other researchers for a similar alloy composition.

  8. Investigations on Heat Treatment of a High-Speed Steel Roll

    NASA Astrophysics Data System (ADS)

    Fu, Hanguang; Qu, Yinhu; Xing, Jiandong; Zhi, Xiaohui; Jiang, Zhiqiang; Li, Mingwei; Zhang, Yi

    2008-08-01

    High-carbon high-speed steels (HSS) are very abrasion-resistant materials primarily due to their high hardness MC-type carbide and high hardness martensitic matrix. The effects of quenching and tempering treatment on the microstructure, mechanical properties, and abrasion resistance of centrifugal casting high-carbon HSS roll were studied. Different microstructures and mechanical properties were obtained after the quenching and tempering temperatures of HSS roll were changed. With air-cooling and sodium silicate solution cooling, when the austenitizing temperature reaches 1273 K, the metallic matrix all transforms into the martensite. Afterwards, the eutectic carbides dissolve into the metallic matrix and their continuous network distribution changes into the broken network. The second hardening temperature of high-carbon HSS roll is around 793 K. No significant changes in tensile strength and elongation percentage are observed unless the tempering temperature is beyond 753 K. The tensile strength increases obviously and the elongation percentage decreases slightly beyond 753 K. However, the tensile strength decreases and the elongation percentage increases when the tempering temperature exceeds 813 K. When the tempering temperature excels 773 K, the impact toughness has a slight decrease. Tempering at 793-813 K, high-carbon HSS roll presents excellent abrasion resistance.

  9. Investigation on Mechanical Properties of 9%Cr/CrMoV Dissimilar Steels Welded Joint

    NASA Astrophysics Data System (ADS)

    Liu, Xia; Lu, Fenggui; Yang, Renjie; Wang, Peng; Xu, Xiaojin; Huo, Xin

    2015-04-01

    Advanced 9%Cr steel with good heat resistance and CrMoV with good toughness were chosen as candidate materials to fabricate combined rotor for steam turbine operating at over 620 °C. But the great difference in base metals properties presents a challenge in achieving sound defect-free joint with optimal properties in dissimilar welded rotor. In this paper, appropriate selection of filler metal, welding parameters, and post-weld heat treatment was combined to successfully weld 1100-mm-diameter 9%Cr/CrMoV dissimilar experimental rotor through ultra-narrow gap submerge arc welding. Some properties such as hardness, low-cycle fatigue (LCF), and high-cycle fatigue (HCF) combined with microstructural characterization qualify the integrity of the weld. Microstructural analysis indicated the presence of high-temperature tempered martensite as the phase responsible for the improved properties obtained in the weld. The Coffin-Manson parameters were obtained by fitting the data in LCF test, while the conditional fatigue strength was derived from the HCF test based on S-N curve. Analysis of hardness profile showed that the lowest value occurred at heat-affected zone adjacent to base metal which represents the appropriate location of fracture for the samples after LCF and HCF tests.

  10. The Investigation of Strain-Induced Martensite Reverse Transformation in AISI 304 Austenitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Cios, G.; Tokarski, T.; Żywczak, A.; Dziurka, R.; Stępień, M.; Gondek, Ł.; Marciszko, M.; Pawłowski, B.; Wieczerzak, K.; Bała, P.

    2017-10-01

    This paper presents a comprehensive study on the strain-induced martensitic transformation and reversion transformation of the strain-induced martensite in AISI 304 stainless steel using a number of complementary techniques such as dilatometry, calorimetry, magnetometry, and in-situ X-ray diffraction, coupled with high-resolution microstructural transmission Kikuchi diffraction analysis. Tensile deformation was applied at temperatures between room temperature and 213 K (-60 °C) in order to obtain a different volume fraction of strain-induced martensite (up to 70 pct). The volume fraction of the strain-induced martensite, measured by the magnetometric method, was correlated with the total elongation, hardness, and linear thermal expansion coefficient. The thermal expansion coefficient, as well as the hardness of the strain-induced martensitic phase was evaluated. The in-situ thermal treatment experiments showed unusual changes in the kinetics of the reverse transformation (α' → γ). The X-ray diffraction analysis revealed that the reverse transformation may be stress assisted—strains inherited from the martensitic transformation may increase its kinetics at the lower annealing temperature range. More importantly, the transmission Kikuchi diffraction measurements showed that the reverse transformation of the strain-induced martensite proceeds through a displacive, diffusionless mechanism, maintaining the Kurdjumov-Sachs crystallographic relationship between the martensite and the reverted austenite. This finding is in contradiction to the results reported by other researchers for a similar alloy composition.

  11. 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.

  12. Experimental investigation on erosive wear behaviour of plasma spray coated stainless steel

    NASA Astrophysics Data System (ADS)

    Girisha, K. G.; Sreenivas Rao, K. V.; Anil, K. C.; Sanman, S.

    2017-04-01

    Slurry erosion is an implicit problem in many engineering industrial components such as ore carrying pipelines, slurry pumps and extruders. Even the water turbine blades are subjected to erosive wear when the water contains considerable amount of silt. In the present study, Al2O3-40%TiO2 powder particles of average particle size of 50 micrometer were deposited on EN56B martenistic stainless steel by atmospheric plasma spray technique. Ni/Cr was pre coated to work as bond coat for good adhesion between coating and the substrate material. A coating thickness of 200 micrometer was achieved. Coated and un-coated substrates were subjected to slurry erosion test as per ASTM G-119 standard. Slurry erosion test rig was used to evaluate the erosion properties at room temperature condition by varying the spindle speed. Scanning electron microphotographs were taken before and after the slurry erosion test. Microstructures reveal uniform distribution of coating materials. Eroded surface shows lip, groove, and crater formation and dense coating resulting in less porosity. Micro hardness test was evaluated and reported. EDX analysis confirms the presence of Al, Ti and O2 particles. It was observed that, Al2O3-40%TiO2 coated substrates exhibit superior erosion resistance as compared to un-coated substrates due to higher hardness and less coating porosity.

  13. Investigation of high temperature corrosion behavior on 304L austenite stainless steel in corrosive environments

    SciTech Connect

    Sahri, M. I.; Othman, N. K.; Samsu, Z.; Daud, A. R.

    2014-09-03

    In this work, 304L stainless steel samples were exposed at 700 °C for 10hrs in different corrosive environments; dry oxygen, molten salt, and molten salt + dry oxygen. The corrosion behavior of samples was analyzed using weight change measurement technique, optical microscope (OM) and Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray (EDX). The existence phases of corroded sample were determined using X-ray Diffraction (XRD). The lowest corrosion rate was recorded in dry oxygen while the highest was in molten salt + dry oxygen environments with the value of 0.0062 mg/cm{sup 2} and −13.5225 mg/cm{sup 2} respectively. The surface morphology of sample in presence of salt mixture showed scale spallation. Oxide scales of Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3} were the main phases developed and detected by XRD technique. Cr{sub 2}O{sub 3} was not developed in every sample as protective layers but chromate-rich oxide was developed. The cross-section analysis found the oxide scales were in porous, thick and non-adherent that would not an effective barrier to prevent from further degradation of alloy. EDX analysis also showed the Cr-element was low compared to Fe-element at the oxide scale region.

  14. Investigation of the Corrosion Inhibition of CTAB and SDS on Carbon Steel Using an Experimental Design Strategy

    NASA Astrophysics Data System (ADS)

    Arjmand, Farzin; Wang, Jiamei; Zhang, Lefu

    2016-03-01

    The corrosion inhibition performance of sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) on carbon steel was investigated in sodium chloride solutions. Using an experimental design strategy pH, chloride concentration, SDS/CTAB concentrations, and temperature were optimized by conducting only 30 experiments. The optimum value of each factor was obtained from the designed matrix of the experiments based on the lowest log I corr value calculated for each experimental condition. The 3D surface plots of the electrochemical response (log I corr) against each factor were constructed. The optimum conditions in which the lowest log I corr can be achieved were found as follows: pH 12, [Cl-] ≈ 1 M, [SDS] ≈ 200 ppm, [CTAB] ≈ 20 ppm, and T ≈ 10 °C.

  15. Carbide precipitates in solution-quenched PH13-8 Mo stainless steel: A small-angle neutron scattering investigation

    NASA Astrophysics Data System (ADS)

    Sen, D.; Patra, A. K.; Mazumder, S.; Mittra, J.; Dey, G. K.; de, P. K.

    2004-08-01

    This paper deals with the small-angle neutron scattering (SANS) investigation on solution-quenched PH13-8 Mo stainless steel. From the nature of the variation of the functionality of the profiles for varying specimen thickness and also from the transmission electron microscopy (TEM), it has been established that the small-angle scattering signal predominantly originates from the block-like metallic carbide precipitates in the specimen. The contribution due to double Bragg reflection is not significant in the present case. The single scattering profile has been extracted from the experimental profiles corresponding to different values of specimen thickness. In order to avoid complexity and non-uniqueness of the multi-parameter minimization for randomly oriented polydisperse block-like precipitate model, the data have been analyzed assuming randomly oriented polydisperse cylindrical particle model with a locked aspect ratio.

  16. Investigation of the Influence Factors on Distortion in Induction-Hardened Steel Shafts Manufactured from Cold-Drawn Rod

    NASA Astrophysics Data System (ADS)

    Dong, Juan; Epp, Jeremy; Rocha, Alexandre da Silva; Nunes, Rafael Menezes; Zoch, Hans Werner

    2016-02-01

    In this study, the distortion of steel shafts was investigated before and after induction hardening. Several essential influencing factors in the manufacturing process chain regarding cold drawing, cutting method, notches on the shafts, and induction hardening were analyzed by design of experiment (DoE). Further necessary examinations of microstructures, hardness profile, segregation of chemical composition, and residual stress state were conducted for understanding the distortion behavior. The results of the statistical analysis of the DoE showed that the drawing process is the most important factor influencing distortion. The surface hardening depth of induction hardening is the second main factor. The relationship between inhomogeneities in the work pieces and the distortion was finally discussed.

  17. Quantitative investigation into the influence of temperature on carbide and austenite evolution during partitioning of a quenched and partitioned steel

    SciTech Connect

    Pierce, Dean T.; Coughlin, D. R.; Williamson, Don L.; Kähkönen, Joonas; Clarke, A. J.; Clarke, Kester D.; Speer, J. G.; De Moor, Emmanuel

    2016-05-03

    Here, the influence of partitioning temperature on microstructural evolution during quenching and partitioning was investigated in a 0.38C-1.54Mn-1.48Si wt.% steel using Mössbauer spectroscopy and transmission electron microscopy. η-carbide formation occurs in the martensite during the quenching, holding, and partitioning steps. More effective carbon partitioning from martensite to austenite was observed at 450 than 400°C, resulting in lower martensite carbon contents, less carbide formation, and greater retained austenite amounts for short partitioning times. Conversely, greater austenite decomposition occurs at 450°C for longer partitioning times. Lastly, cementite forms during austenite decomposition and in the martensite for longer partitioning times at 450°C.

  18. Comparison Between Corrosion Behavior of Copper and Stainless Steel 90° Elbow and Failure Investigation of 90° Copper Elbow

    NASA Astrophysics Data System (ADS)

    Fouad, Mohamed Ahmed; Zewail, Taghreed Mohamed; Amine, Nieven Abbas; El-Tawail, Yehia Ahmed

    2016-06-01

    Frequently found in elbow, erosion failures may lead to the leakage of pipes and even damage the whole system. Erosion is a form of material degradation that involves electrochemical corrosion and mechanical wear processes encountered on the surface of metal pipes. Research on the erosion-corrosion mechanism indicates that the erosion mainly results from the interactions between the elbow surface and the fluid traveling along the surface. Corrosion behavior of 90° copper and stainless steel elbow was studied. Scanning electron microscopy was processed on the 90° copper elbow to show the surface morphology of the failed copper elbow. Failure investigation was carried out on 90° copper elbow to determine failure location and failure causes.

  19. Investigations of structural transformation within metal (austenite chromium-manganese steel) at the external surface of steam superheating tubes

    NASA Astrophysics Data System (ADS)

    Bogachev, V. A.; Pshechenkova, T. P.; Shumovskaya, M. A.

    2016-04-01

    The elemental composition of an altered layer at the external surface of a steam superheating tube of grade DI59 steel is investigated after long-term operation. It is shown that the layer is located between a scale and a matrix and depleted by silicon, manganese, copper, and chromium with the maximum oxidizer affinity, enriched by iron and nickel to 90%, and mainly composed of the α-Fe phase (ferrite) with the ferromagnetic properties. The layer formed as a result of selective oxidation and diffusion from the matrix into the metal scale with the less standard free energy of the formation of sulfides and oxides. A magnetic ferrite meter is used in the experimental investigation of the layer evolution by testing grade DI59 steel for heat resistance in air environment at temperatures of 585, 650, and 700°C for 15 × 103 h; creep at a temperature of 750°C and a stress of 60 MPa; and long-term strength at temperatures of 700 and 750°C and stresses of from 30 to 80 MPa. Specimens for tests are made of tubes under as-received conditions. The relationship between the ferrite phase content in the surface metal layer and the temperature and time of test is determined. The dependence is developed to evaluate the equivalent temperature for operation of the external surface of steam superheating tubes using data of magnetic ferritometry. It is shown that operation temperatures that are determined by the ferrite phase content and the σ phase concentration in the metal structure of steam superheating tubes with the significant operating time are close. It is proposed to use magnetic ferritometry for revelation of thermal nonuniformity and worst tubes of steam superheaters of HPP boilers.

  20. COUPLED MULTI-ELECTRODE INVESTIGATION OF CREVICE CORROSION OF 316 STAINLESS STEEL

    SciTech Connect

    F. Bocher, J. R. Scully

    2006-01-30

    impedance-capable MMA, it is also possible to monitor the film breakdown and the early stages of crevice corrosion as a function of the wires position. In this talk, the use of multi-electrode array to study crevice corrosion of 316 stainless steel and a Ni-Cr-Mo alloy is reviewed.

  1. COUPLED MULTI-ELECTRODE INVESTIGATION OF CREVICE CORROSION OF 316 STAINLESS STEEL

    SciTech Connect

    F. Bocher and J. R. Scully

    2006-01-30

    impedance-capable MMA, it is also possible to monitor the film breakdown and the early stages of crevice corrosion as a function of the wires position. In this talk, the use of multi-electrode array to study crevice corrosion of 316 stainless steel and a Ni-Cr-Mo alloy is reviewed.

  2. Investigation of temperature dependence of fracture toughness in high-dose HT9 steel using small-specimen reuse technique

    NASA Astrophysics Data System (ADS)

    Baek, Jong-Hyuk; Byun, Thak Sang; Maloy, Start A.; Toloczko, Mychailo B.

    2014-01-01

    The temperature dependence of fracture toughness in HT9 steel irradiated to 3-145 dpa at 380-503 °C was investigated using miniature three-point bend (TPB) fracture specimens. A miniature-specimen reuse technique has been established: the tested halves of subsize Charpy impact specimens with dimensions of 27 mm × 3 mm × 4 mm were reused for this fracture test campaign by cutting a notch with a diamond-saw in the middle of each half, and by fatigue-precracking to generate a sharp crack tip. It was confirmed that the fracture toughness of HT9 steel in the dose range depends more strongly on the irradiation temperature than the irradiation dose. At an irradiation temperature <430 °C, the fracture toughness of irradiated HT9 increased with the test temperature, reached an upper shelf of 180-200 MPa √{m} at 350-450 °C, and then decreased with the test temperature. At an irradiation temperature ⩾430 °C, the fracture toughness was nearly unchanged up to about 450 °C and decreased slowly with test temperatures in a higher temperature range. Such a rather monotonic test temperature dependence after high-temperature irradiation is similar to that observed for an archive material generally showing a higher degree of toughness. A brittle fracture without stable crack growth occurred in only a few specimens with relatively lower irradiation and test temperatures. In this discussion, these TPB fracture toughness data are compared with previously published data from 12.7 mm diameter disc compact tension (DCT) specimens.

  3. Experimental investigation and modelling of surface roughness and resultant cutting force in hard turning of AISI H13 Steel

    NASA Astrophysics Data System (ADS)

    Boy, M.; Yaşar, N.; Çiftçi, İ.

    2016-11-01

    In recent years, turning of hardened steels has replaced grinding for finishing operations. This process is compared to grinding operations; hard turning has higher material removal rates, the possibility of greater process flexibility, lower equipment costs, and shorter setup time. CBN or ceramic cutting tools are widely used hard part machining. For successful application of hard turning, selection of suitable cutting parameters for a given cutting tool is an important step. For this purpose, an experimental investigation was conducted to determine the effects of cutting tool edge geometry, feed rate and cutting speed on surface roughness and resultant cutting force in hard turning of AISI H13 steel with ceramic cutting tools. Machining experiments were conducted in a CNC lathe based on Taguchi experimental design (L16) in different levels of cutting parameters. In the experiments, a Kistler 9257 B, three cutting force components (Fc, Ff and Fr) piezoelectric dynamometer was used to measure cutting forces. Surface roughness measurements were performed by using a Mahrsurf PS1 device. For statistical analysis, analysis of variance has been performed and mathematical model have been developed for surface roughness and resultant cutting forces. The analysis of variance results showed that the cutting edge geometry, cutting speed and feed rate were the most significant factors on resultant cutting force while the cutting edge geometry and feed rate were the most significant factor for the surface roughness. The regression analysis was applied to predict the outcomes of the experiment. The predicted values and measured values were very close to each other. Afterwards a confirmation tests were performed to make a comparison between the predicted results and the measured results. According to the confirmation test results, measured values are within the 95% confidence interval.

  4. Investigation of temperature dependence of fracture toughness in high-dose HT9 steel using small-specimen reuse technique

    SciTech Connect

    Baek, Jong-Hyuk; Byun, Thak Sang; Maloy, Stuart A.; Toloczko, Mychailo B.

    2014-01-01

    The temperature dependence of fracture toughness in HT9 steel irradiated to 3–145 dpa at 380–503 degrees*C was investigated using miniature three-point bend (TPB) fracture specimens. A miniature-specimen reuse technique has been established: the tested halves of subsize Charpy impact specimens with dimensions of 27 mm *3mm* 4 mm were reused for this fracture test campaign by cutting a notch with a diamond-saw in the middle of each half, and by fatigue-precracking to generate a sharp crack tip. It was confirmed that the fracture toughness of HT9 steel in the dose range depends more strongly on the irradiation temperature than the irradiation dose. At an irradiation temperature <430 *degreesC, the fracture toughness of irradiated HT9 increased with the test temperature, reached an upper shelf of 180—200 MPa*m^.5 at 350–450 degrees*C, and then decreased with the test temperature. At an irradiation temperature >430 degrees*C, the fracture toughness was nearly unchanged up to about 450 *degreesC and decreased slowly with test temperatures in a higher temperature range. Such a rather monotonic test temperature dependence after high-temperature irradiation is similar to that observed for an archive material generally showing a higher degree of toughness. A brittle fracture without stable crack growth occurred in only a few specimens with relatively lower irradiation and test temperatures. In this discussion, these TPB fracture toughness data are compared with previously published data from 12.7 mm diameter disc compact tension (DCT) specimens.

  5. Investigation of temperature dependence of fracture toughness in high-dose HT9 steel using small-specimen reuse technique

    SciTech Connect

    Baek, Jong-Hyuk; Byun, Thak Sang; Maloy, S; Toloczko, M

    2014-01-01

    The temperature dependence of fracture toughness in HT9 steel irradiated to 3 145 dpa at 380 503 C was investigated using miniature three-point bend (TPB) fracture specimens. A miniature-specimen reuse technique has been established: the tested halves of subsize Charpy impact specimens with dimensions of 27 mm 3mm 4 mm were reused for this fracture test campaign by cutting a notch with a diamond-saw in the middle of each half, and by fatigue-precracking to generate a sharp crack tip. It was confirmed that the fracture toughness of HT9 steel in the dose range depends more strongly on the irradiation temperature than the irradiation dose. At an irradiation temperature <430 C, the fracture toughness of irradiated HT9 increased with the test temperature, reached an upper shelf of 180 200 MPa ffiffiffiffiffi m p at 350 450 C, and then decreased with the test temperature. At an irradiation temperatureP430 C, the fracture toughness was nearly unchanged up to about 450 C and decreased slowly with test temperatures in a higher temperature range. Such a rather monotonic test temperature dependence after high-temperature irradiation is similar to that observed for an archive material generally showing a higher degree of toughness. A brittle fracture without stable crack growth occurred in only a few specimens with relatively lower irradiation and test temperatures. In this discussion, these TPB fracture toughness data are compared with previously published data from 12.7 mm diameter disc compact tension (DCT) specimens.

  6. 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

  7. Investigation of the Microstructural, Mechanical and Corrosion Properties of Grade A Ship Steel-Duplex Stainless Steel Composites Produced via Explosive Welding

    NASA Astrophysics Data System (ADS)

    Kaya, Yakup; Kahraman, Nizamettin; Durgutlu, Ahmet; Gülenç, Behçet

    2017-08-01

    Grade A ship-building steel-AISI 2304 duplex stainless steel composite plates were manufactured via explosive welding. The AISI 2304 plates were used to clad the Grade A plates. Optical microscopy studies were conducted on the joining interface for characterization of the manufactured composite plates. Notch impact, tensile-shear, microhardness, bending and twisting tests were carried out to determine the mechanical properties of the composites. In addition, the surfaces of fractured samples were examined by scanning electron microscopy (SEM), and neutral salt spray (NSS) and potentiodynamic polarization tests were performed to examine corrosion behavior. Near the explosion zone, the interface was completely flat, but became wavy as the distance from the explosion zone increased. The notch impact tests indicated that the impact strength of the composites decreased with increasing distance from the explosion zone. The SEM studies detected brittle behavior below the impact transition temperature and ductile behavior above this temperature. Microhardness tests revealed that the hardness values increased with increasing distance from the explosion zone and mechanical tests showed that no visible cracking or separation had occurred on the joining interface. The NSS and potentiodynamic polarization tests determined that the AISI 2304 exhibited higher corrosion resistance than the Grade A steel.

  8. Soybean oil and methyl oleate adsorption onto a steel surface investigated using a quartz crystal microbalance with dissipation monitoring and atomic force microscopy**1

    USDA-ARS?s Scientific Manuscript database

    The United States’ 2010 annual production of soybean oil exceeded 8 million metric tons, making a significant vegetable oil surplus available for new uses, particularly as a lubricant. Investigation of soybean oil and methyl oleate adsorption onto steel using a quartz crystal microbalance with diss...

  9. Investigation of effects of long-term thermal aging on magnetization process in low-alloy pressure vessel steels using first-order-reversal-curves

    NASA Astrophysics Data System (ADS)

    Kobayashi, Satoru; Gillemot, Ferenc; Horváth, Ákos; Horváth, Márta; Almásy, László; Tian, Qiang; Feoktystov, Artem

    2017-05-01

    We have investigated effects of long-term thermal aging at 550°C up to 10000 h on major-loop coercivity, hysteresis scaling of minor loops, and first-order reversal curves (FORCs) for low-alloy pressure vessel steels with low and high Ni contents. While major-loop coercivity and minor-loop coefficient of the scaling exhibit a gradual decrease with aging for high-Ni steel, those for low-Ni one are very weakly dependent on aging time. On the other hand, we found that FORC distribution becomes steep along both axes of interaction and switching fields and the peak shifts toward a lower switching field for both steels. Considering that there is no significant development of nanoscale precipitates during the aging as revealed with small-angle neutron scattering experiments, a relaxation of lattice strain in a matrix, possibly associated with diffusion of Ni atoms, may dominate magnetic properties at 550°C.

  10. Ultrahigh carbon steels, Damascus steels, and superplasticity

    SciTech Connect

    Sherby, O.D.; Wadsworth, J.

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  11. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  12. Results of stainless steel canister corrosion studies and environmental sample investigations

    SciTech Connect

    Bryan, Charles R.; Enos, David

    2014-12-01

    . At both sites, the surface dust could be divided into fractions generated by manufacturing processes and by natural processes. The fraction from manufacturing processes consisted of variably-oxidized angular and spherical particles of stainless steel and iron, generated by machining and welding/cutting processes, respectively. Dust from natural sources consisted largely of detrital quartz and aluminosilicates (feldspars and clays) at both sites. At Hope Creek, soluble salts were dominated by sulfates and nitrates, mostly of calcium. Chloride was a trace component and the only chloride mineral observed by SEM was NaCl. Chloride surface loads measured by the Saltsmart™ sensors were very low, less than 60 mg m–2 on the canister top, and less than 10 mg m–2 on the canister sides. At Diablo Canyon, sea-salt aggregates of NaCl and Mg-SO4, with minor K and Ca, were abundant in the dust, in some cases dominating the observed dust assemblage. Measured Saltsmart™ chloride surface loads were very low (<5 mg m–2); however, high canister surface temperatures damaged the Saltsmart™ sensors, and, in view of the SEM observations of abundant sea-salts on the package surfaces, the measured surface loads may not be valid. Moreover, the more heavily-loaded canister tops at Diablo Canyon were not sampled with the Saltsmart™ sensors. The observed low surface loads do not preclude chloride-induced stress corrosion cracking (CISCC) at either site, because (1) the measured data may not be valid for the Diablo Canyon canisters; (2) the surface coverage was not complete (for instance, the 45º offset between the outlet and inlet vents means that near-inlet areas, likely to have heavier dust and salt loads, were not sampled); and (3) CISCC has been experimentally been observed at salt loads as low as 5-8 mg/m2. Experimental efforts at SNL to assess corrosion of interim storage canister materials include three tasks in FY14

  13. Investigation of the Hot-Stamping Process for Advanced High-Strength Steel Sheet by Numerical Simulation

    NASA Astrophysics Data System (ADS)

    Liu, H. S.; Xing, Z. W.; Bao, J.; Song, B. Y.

    2010-04-01

    Hot forming is a new way to manufacture complex-shaped components of advanced high-strength steel (AHSS) sheet with a minimum of spring-back. Numerical simulation is an effective way to examine the hot-forming process, particularly to determine thermal and thermo-mechanical characteristics and their dependencies on temperature, strain and strain rate. The flow behavior of the 22MnB5 AHSS is investigated through hot tensile tests. A 3D finite element (FE) model of hot-stamping process for the [InlineMediaObject not available: see fulltext.] shaped part is built under the ABAQUS/Explicit environment based on the solutions of several key problems, such as treatment of contact between blank and tools, determination of material characteristics and meshing, etc. Numerical simulation is carried out to investigate the influence of blank holder force (BHF) and die gap on the hot-forming process for the [InlineMediaObject not available: see fulltext.] shaped part. Numerical results show the FE model is effective in simulation of hot-forming process. Large BHF reduces the amount of spring-back and improves the contact of flange with tools while avoiding cracking of stamped part. Die gap has a considerable influence on the distribution of temperature on side walls; the larger the die gap, higher is the temperature on the sidewall of [InlineMediaObject not available: see fulltext.] shaped part.

  14. Investigation of corrosion of commercial grade AISI 316L stainless steel liner plates in desalination plant conditions

    SciTech Connect

    Saricimen, H.; Jarrah, N.R.; Allam, I.M.

    1994-12-31

    The corrosion of AISI Type 316L stainless steel (316L SS) liner plates in the flash chambers of a multistage flash (MSF) desalination plant, located on the Arabian Gulf coast was investigated. The 316L SS liner plates developed severe corrosion within six years of operation. This study was conducted to develop an understanding of the mode and causes of corrosion of the liner plates, and to determine the effect of heat treatment (annealing or heat effect during welding) and temperature of salt solution on corrosion of the liner plates. Specimens of the liner plates were studied in as-received (AR) condition and after being heat treated (HT) at 900 C in air and air-cooled to room temperature. Electrochemical techniques were used to measure the corrosion of the specimens. Scanning electron microscope (SEM) installed with energy dispersive (ED) X-ray diffraction capability was used for identification of compositional and structural changes in the specimens during heat treatment and corrosion. The results showed that: (1) Commercial grade 316L SS is susceptible to pitting, crevice and grain boundary corrosion under the operating conditions in the desalination plant. The heat-affected-zone (HAZ) had larger grains and corroded more severely than other parts of the liner plates. (2) The liner plates had randomly distributed inclusions containing Ti, Cr, Mo, Mn, and S in the structure. (3) Measurement of the corrosion rate. (4) Metallographic investigation of the AR and HT samples.

  15. Investigation on the Interface Morphologies of Explosive Welding of Inconel 625 to Steel A516 Plates

    SciTech Connect

    Mousavi, S. A. A. Akbari; Zareie, H. R.

    2011-01-17

    The purpose of this study is to produce composite plates by explosive cladding process. This is a process in which the controlled energy of explosives is used to create a metallic bond between two similar or dissimilar materials. The welding conditions were tailored through parallel geometry route with different operational parameters. In this investigation, a two-pronged study was adopted to establish the conditions required for producing successful solid state welding: (a) Analytical calculations to determine the weldability domain or welding window; (b) Metallurgical investigations of explosive welding experiments carried out under different explosive ratios to produce both wavy and straight interfaces. The analytical calculations confirm the experimental results. Optical microscopy studies show that a transition from a smooth to wavy interface occurs with an increase in explosive ratio. SEM studies show that the interface was outlined by characteristic sharp transition between two materials.

  16. 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.

  17. Metallurgical Investigation of a Steel Miner's Chisel From Ponte Val Gabbia III Site

    NASA Astrophysics Data System (ADS)

    Cornacchia, Giovanna; Faccoli, Michela; Roberti, Roberto

    2015-01-01

    Recent research on ancient ferrous artefacts belonging to different historical periods has indicated significant differences in various parameters characterizing the slags entrapped in these artefacts, in cases where they were obtained by using different production methods. Such differences have been observed by comparing "ancient period" artefacts with "subsequent period" artefacts. "Ancient period" products were obtained by direct reduction of iron ore, without carburizing and at temperatures below the melting point of the reduced sponge iron. In the "subsequent period", the indirect process started to be introduced, with the production, in a first reduction stage, of a liquid cast iron that had to be converted to wrought iron during a second fining operation. The understanding of the characterizing parameters of the slags has in fact progressed to the point where they represent a useful tool not only for inferring the origins of the starting ore but also for distinguishing between direct or indirect production. In the present research work, an accurate study of the entrapped slags has been carried out on an artefact from the Val Gabbia III site, identified in previous studies as a miner's chisel. This study aims to carry out further metallurgical investigation into the miner's chisel microstructure and the entrapped slags in order to help ascertain which production method was in use at the Val Gabbia III site; in fact, based on the intrinsic characteristics of the chisel, and the fact that the site where it was found, i.e. layers of the V-VI cent AD in Val Gabbia III site, was characterized by the presence of an almost 3.5 kg cast iron block, previous investigators were led to suppose that it may be a very early site of indirect iron smelting. While the slag characterizing parameters obtained in the present investigation appear to be consistent with published results related to the direct method, the discussion on the relationship between the indirect method

  18. An Investigation of The Reticulated Foam - Perforated Steel Sheet Sandwich Structure As A Blast Mitigation Media

    NASA Astrophysics Data System (ADS)

    Nguyen, Thuy-Tien Ngoc; Proud, William; Institute of Shock Physics, Imperial College London Collaboration; Royal British Legion CentreBlast Injury Studies at Imperial College London Collaboration

    2015-06-01

    Explosions have always been the main cause of injuries during battles and conflicts, with improvised explosive devices (IEDs) becoming more and more common nowadays. In this paper, the interaction between blast waves and sandwich structures of reticulated foam and perforated sheets, with varying thickness and configuration, is studied using an air-driven shock tube apparatus. The mitigation effects for primary blast injuries of these structures are discussed in terms of pulse shape, pressure magnitude as well as shock impulse. Schlieren photography together with other high-speed imaging was also used to visually investigate the matter. The results show that lower open area of perforated sheet and increased thickness of foam offer best protection. However, below a threshold thickness, no mitigation is seen. The Institute of Shock Physics acknowledges the support of AWE, Aldermaston, UK and Imperial College London. The Centre for Blast Injury Studies acknowledges the support of the Royal British Legion and Imperial College London.

  19. Computational Investigation of the Influence of Fly Ash Silica Content and Shape on the Erosion Behaviour of Indian Coal Fired Boiler Grade Steels

    NASA Astrophysics Data System (ADS)

    Kumari, Amrita; Das, Suchandan Kumar; Srivastava, Prem Kumar

    2016-07-01

    A mathematical model has been developed to characterize the erosion behaviour of fly ash on boiler grade steel surfaces incorporating various ductile erosion mechanisms. These mechanisms constitute cutting wear, repeated plastic deformation and effect of operating temperature on the mechanical properties of the substrate. Parametric analysis has been carried out to study the erosion response of some typical steel grades as a function of particle impact parameters such as particle impact velocity, angle of impingement coupled with the effect of temperature on the tensile properties. Further, effects of fly ash properties such as hardness (silica content) and shape (angularity) on the erosion response have been also investigated along with the ballistic parameters. These investigations show that a small increment in the fly ash hardness can considerably augment the erosion rate of the steel surface under a given particle impingement condition. This vindicates that hardness of fly ash is one of the most critical parameter which has a direct impact in enhancing the erosion rate of boiler grade steels. The effect of fly ash shape on the erosion behaviour is also studied in conjunction with the particle hardness. This shows that the composite action of these parameters augment the erosion rate significantly.

  20. An Investigation Utilizing an Electrical Analogue of Cyclic Deicing of a Hollow Steel Propeller with an External Blade Shoe

    NASA Technical Reports Server (NTRS)

    Neel, Carr B., Jr.

    1952-01-01

    A study has been made of the heat requirement for the cyclic de-icing of hollow steel propellers fitted with external blade heating shoes. Solutions to the equations for the heat flow in cyclic heating of propellers were obtained, using an electrical analogy. The study showed how the energy requirement for propeller de-icing with existing blade shoes could be decreased, and illustrated the effect of blade-shoe design on the energy requirement. It was demonstrated, for example, that by increasing the heating intensity and decreasing the heating period from those currently used the energy requirement could be decreased in the order of 60 percent. ' In addition, ft was shown that heating requirements could be decreased further, by as much as 60 percent, through proper design of the shoes. The' investigation also showed the energy requirement to increase with decreasing liquid-water content and air temperature. Uncertainties as to the exact values of convective heat-transfer coefficient prevailing over the surface of the blade and ice layer resulted in uncertainties of approximately proportional magnitude in the values of required heating intensity.

  1. Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 1: Unpartitioned Blades

    NASA Technical Reports Server (NTRS)

    Mulholland, Donald R.; Perkins, Porter J.

    1948-01-01

    An investigation to determine the effectiveness of icing protection afforded by air-heating hollow steel unpartitioned propeller blades has been conducted In the NACA Cleveland icing research tunnel. The propeller used was a production model modified with blade shank and tip openings to permit internal passage of heated air. Blade-surface and heated-air temperatures were obtained and photographic observations of Ice formations were made with variations In icing intensity and heating rate to the blades. For the conditions of Icing to which the propeller was subjected, it was found that adequate ice protection was afforded with a heating rate of 40 1 000 Btu per hour per blade. With less than 40,000 Btu per hour per blade, ice protection failed because of significant ice accretions on the leading edge. The chordwise distribution of heat was unsatisfactory with most of the available heat dissipated well back of the leading edge on both the thrust and camber face's instead of at the leading edge where it was most needed. A low utilization of available heat for icing protection is indicated by a beat-exchanger effectiveness of approximately 47 percent.

  2. Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection Against Icing. 2: 50% Impartitioned Blades

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J.; Mulholland, Donald R.

    1948-01-01

    The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel Icing' conditions. Photographic observations of ice formations on blade surfaces and blade heat-exchanger effectiveness were obtained. With 50-percent partitioning of the blades, adequate icing protection at 1050 rpm was obtained with a heating rate of 26,000 Btu per hour per blade at the blade shank using an air temperature of 400 F with a flow rate of 280 pounds per hour per blade, which is one-third less heat than was found necessary for similar Ice protection with unpartitioned blades. The chordwise distribution of the applied heat, as determined by surface temperature measurements, was considered unsatisfactory with much of the heat dissipated well back of the leading edge. Heat-exchanger effectiveness of approximately 56 percent also Indicated poor utilization of available heat. This effectiveness was, however, 9 percent greater than that obtained from unpartitioned blades.

  3. Investigation on Twisting and Side Wall Opening Occurring in Curved Hat Channel Products Made of High Strength Steel Sheets

    NASA Astrophysics Data System (ADS)

    Takamura, Masato; Fukui, Ayako; Yano, Hiroshi; Hama, Takayuki; Sunaga, Hideyuki; Makinouchi, Akitake; Asakawa, Motoo

    2011-08-01

    High strength steel sheets are becoming increasingly important for the weight reduction of automotive bodies to meet the requirements for reduced environmental impact. However, dimensional defects resulting from springback are serious issues, and effective methods of predicting and reducing such defects are necessary. In this study, we numerically and experimentally analyzed the mechanisms of dimensional inaccuracies caused by springback occurring in curved hat channel deep drawing products. The analysis was based on the static explicit FEM software "TP-STRUCT" (the solver part is known as "STAMP3D"). The results of the experiments and simulations similarly show that the twist angle is positive (right-hand system) when the drawing height is relatively large. We calculated the twist torque around the longitudinal axis using the stress distributions obtained by FE analysis. Through the investigation of twist torque and its transition during the drawing and die removal processes, we found that the negative torque generated by side wall opening occurring in the die removal process is the dominant factor of the positive twist. Knowing such mechanisms of twist in cases with a relatively large drawing height, we attempted to explore methods of reducing side wall opening by giving the side wall a stepped shape with the eventual aim of reducing twist. Consequently, we concluded that the stepped shape on the side wall has marked effects of reducing side wall opening, mainly through the elimination of bending-unbending effects on die shoulders, which was verified by observing the stress distribution obtained by FE analysis.

  4. Investigation of plume dynamics during picosecond laser ablation of H13 steel using high-speed digital holography

    NASA Astrophysics Data System (ADS)

    Pangovski, Krste; Otanocha, Omonigho B.; Zhong, Shan; Sparkes, Martin; Liu, Zhu; O'Neill, William; Li, Lin

    2017-02-01

    Ablation of H13 tool steel using pulse packets with repetition rates of 400 and 1000 kHz and pulse energies of 75 and 44 μ {J}, respectively, is investigated. A drop in ablation efficiency (defined here as the depth per pulse or μ {m}{/}μ {J}) is shown to occur when using pulse energies of E_{{pulse}} > 44 μ {J}, accompanied by a marked difference in crater morphology. A pulsed digital holographic system is applied to image the resulting plumes, showing a persistent plume in both cases. Holographic data are used to calculate the plume absorption and subsequently the fraction of pulse energy arriving at the surface after traversing the plume for different pulse arrival times. A significant proportion of the pulse energy is shown to be absorbed in the plume for E_{{pulse}} > 44 μ {J} for pulse arrival times corresponding to {>}1 MHz pulse repetition rate, shifting the interaction to a vapour-dominated ablation regime, an energetically costlier ablation mechanism.

  5. Investigation on laser forming of stainless steel sheets under coupling mechanism

    NASA Astrophysics Data System (ADS)

    Chakraborty, Shitanshu S.; Maji, Kuntal; Racherla, Vikranth; Nath, Ashish K.

    2015-08-01

    In laser forming of three dimensional surfaces simultaneous bending and thickening of the sheet being formed are often required. Laser forming by the coupling mechanism has the capability to generate both of them. However, literature is scarce on the study of laser forming under coupling mechanism. A part of this work investigates the effect of Fourier number and laser spot diameter on bending angle and thickness increment induced by laser scans promoting coupling mechanism. Peak surface temperature was maintained nearly constant. It was chosen so as to avoid surface melting and sensitization at the scan track on top surface. The required laser parameters were determined with the help of an analytical model for temperature estimation. The experimental results showed that while the bending angle reduced with the increase of Fourier number, the thickness increment increased. And, with the increase of laser spot diameter both bending angle and thickness increased. Finite element simulations were carried out using ABAQUS software on a three dimensional model for developing a better understanding of the deformation behaviour. Multimode intensity distribution of the laser beam and temperature dependant material properties were considered in the simulations. Finite element analysis and microstructure study showed that chances of sensitization are rare with the current laser parameter combinations. Based on temperature gradient and coupling mechanisms a different laser scanning strategy has been proposed for laser forming of deep pillow shaped surfaces retaining symmetry.

  6. Investigation of Contact Fatigue of High Strength Steel Gears Subjected to Surface Treatment

    NASA Astrophysics Data System (ADS)

    Dimitrov, L.; Michalopoulos, D.; Apostolopoulos, Ch. Alk.; Neshkov, T. D.

    2009-10-01

    In this paper the contact fatigue resistance of gearwheel teeth, subjected to shot-peening treatment, was investigated experimentally and analytically. The main objective was the evaluation and prediction of fatigue crack initiation, propagation, direction, and rate. A specially designed experimental rig was used to test a number of spur gears with the following characteristics: (a) unhardened, thermally untreated unpeened surfaces, (b) thermally treated unpeened surfaces, (c) unhardened peened surfaces, and (d) thermally treated peened surfaces. The theoretical model assumed initiation and propagation of surface cracks of gears operating in the elastohydrodynamic lubrication regime while loading was due to simultaneous rolling and sliding. Finite element modeling was used for the calculation of the stress field at the gear teeth. Comparison of the experimental and analytical results showed considerable improvement in the contact fatigue strength of thermally treated gear teeth and especially those that underwent shot peening, which increased surface durability. The residual stresses induced by shot peening are mainly effective in stopping microcrack propagation. When shot peening is applied on thermally untreated gear teeth surface, it increases the contact fatigue life of the material by 17% at 7 × 105 loading cycles. If shot peening is applied on carburized gear teeth surfaces, it increases the surface fatigue life by approximately 8% at 106 cycles. Contact fatigue and eventual pitting are treated as a normal consequence of the operation of machine elements. To study this failure process different types of testing machines have been designed. The purpose of this paper is the presentation and evaluation of a new design experimental rig for studying contact fatigue damage of gear teeth subjected to different load patterns.

  7. Investigation into the effects of stainless steel ligature ties on the mechanical characteristics of conventional and self-ligated brackets subjected to torque.

    PubMed

    Al Fakir, Hussam; Carey, Jason P; Melenka, Garrett W; Nobes, David S; Heo, Giseon; Major, Paul W

    2014-09-01

    Torque is applied to orthodontic brackets in order to alter the buccal-lingual angulation of a tooth. One factor that can affect torque is the ligation mode used to retain the archwire in the bracket slot. The objective of this study was to investigate the effects of stainless steel ligation on torque expression and bracket deformation. This study utilized 60 upper right central incisor Damon Q brackets and 60 Ormco Orthos Twin brackets. The brackets used in this study were subdivided into four groups: (1) Damon Q ligated with SS ligature; (2) Damon Q with the sliding bracket door; (3) Orthos Twin bracket ligated with SS wire; and (4) Orthos Twin ligated with elastic ties. All brackets were tested using an orthodontic torque simulating device that applied archwire rotation from 0° to 45°. All brackets ligated with stainless steel ties exhibited greater torque expression and less deformation than brackets without stainless steel ties. As well, Damon Q brackets exhibit less bracket deformation than Orthos Twin brackets. Stainless steel ties can reduce the amount of plastic deformation for both types of brackets used in this study. © 2014 British Orthodontic Society.

  8. Investigations Into the Influence of Weld Zone on Formability of Fiber Laser-Welded Advanced High Strength Steel

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, K.; Panda, S. K.; Saha, P.

    2014-04-01

    In this study, two different dual phase steel grades DP980 and DP600, and IFHS steel sheets were laser welded by a 2-kW fiber laser. The weld quality of these three different LWBs was assessed with the help of microstructure, micro-hardness and transverse tensile tests. Tensile testing of longitudinal and miniature samples was performed to evaluate the mechanical properties of the weld zone. Formability of parent materials and LWBs were assessed in bi-axial stretch forming condition by Erichsen cupping test. To validate the weld zone properties, 3-D finite element models of Erichsen cupping test of LWBs was developed, and the failures in the deformed cups were predicted using two theoretical forming limit diagrams. It was observed that hardness of the fusion zone and HAZ in laser welded DP600 and IFHS steels was more compared to the respective parent metal. However, 29% reduction in hardness was observed at the outer HAZ of DP980 steel weldments due to tempering of martensite. Reduction of formability was observed for all the LWBs with two distinct failure patterns, and the maximum reduction in formability was observed in the case of DP980 LWBs. The presence of the soft zone is detrimental in forming of welded DP steels.

  9. The investigation of the deformation wave hardening effect on the strength of the medium and low alloy steels

    NASA Astrophysics Data System (ADS)

    Kirichek, A. V.; Barinov, S. V.; Yashin, A. V.; Kolontsov, S. E.

    2017-02-01

    The article presents the data on the effect of wave deformation hardening on the strength of the 45, 40X and 35 HGSA steel. To improve the strength of these steels, it is proposed to create structured areas consisting of alternating solid and viscous-plastic sections in their surface layer. The evenness of arrangement of the sections is characterized by the overlap factor. The studies found that wave deformation treatment of the samples, made of the 45, 40X 35HGSA steel, made it possible to increase the tensile strength by 8, 4.2 and 13%, the values of elastic deformations – by 37, 81 and 51% during their hardening with overlapping coefficients 0.7; 0.9 and 0.7, respectively.

  10. Sealed source and device design safety testing. Volume 5: Technical report on the findings of Task 4, Investigation of failed radioactive stainless steel troxler gauges

    SciTech Connect

    Benac, D.J.; Schick, W.R.

    1995-10-01

    This report covers the Task 4 activities for the Sealed Source and Device Safety testing program. SwRI was contracted to investigate failed radioactive stainless steel troxler gauges. SwRI`s task was to determine the cause of failure of the rods and the extent of the problem. SwRI concluded that the broken rod failed in a brittle manner due to a hard zone in the heat affected zone.

  11. Influence of fluence rate on radiation-induced mechanical property changes in reactor pressure vessel steels

    SciTech Connect

    Hawthorne, J.R.; Hiser, A.L. )

    1990-03-01

    This report describes a set of experiments undertaken using a 2 MW test reactor, the UBR, to qualify the significance of fluence rate to the extent of embrittlement produced in reactor pressure vessel steels at their service temperature. The test materials included two reference plates (A 302-B, A 533-B steel) and two submerged arc weld deposits (Linde 80, Linde 0091 welding fluxes). Charpy-V (C{sub v}), tension and 0.5T-CT compact specimens were employed for notch ductility, strength and fracture toughness (J-R curve) determinations, respectively. Target fluence rates were 8 {times} 10{sup 10}, 6 {times} 10{sup 11} and 9 {times} 10{sup 12} n/cm{sup 2} {minus}s{sup {minus}1}. Specimen fluences ranged from 0.5 to 3.8 {times} 10{sup 19} n/cm{sup 2}, E > 1 MeV. The data describe a fluence-rate effect which may extend to power reactor surveillance as well as test reactor facilities now in use. The dependence of embrittlement sensitivity on fluence rate appears to differ for plate and weld deposit materials. Relatively good agreement in fluence-rate effects definition was observed among the three test methods. 52 figs., 4 tabs.

  12. Nondestructive evaluation of neutron irradiation embrittlement for reactor vessel steel by magnetomechanical acoustic emission technique

    SciTech Connect

    Maeda, Noriyoshi; Yamaguchi, Atsunori; Saito, Kiyoshi; Hirasawa, Taiji; Komura, Ichiroh; Chujou, Noriyuki

    1999-10-01

    A modified magnetomechanical acoustic emission (MAE) technique denoted Pulse MAE, in which the magnetizing current has a rectangular wave form, was developed as an NDE technique. Its applicability to the radiation damage for reactor pressure vessel steel was evaluated. The reactor pressure vessel steel A533B base metal and weld metal were irradiated to the two fluence levels: 5 {times} 10{sup 22} and 3 {times} 10{sup 23} n/m{sup 2} at 288 C. One side of the specimen was electropolished after irradiation. Pulse MAE signals were measured with a 350 kHz resonance frequency AE sensor at the moment when the magnetizing voltage is applied from zero to the set-up value abruptly. The AE signals were analyzed and the peak voltage Vp was determined for the measuring parameter. The peak voltage Vp showed the tendency to increase monotonically with increasing neutron fluence. The relationship between the Vp and mechanical properties such as yield stress, tensile strength and Charpy transition temperature were also obtained. The Pulse MAE technique proved to have the possibility to detect and evaluate the neutron irradiation embrittlement. The potential of the Pulse MAE as an effective NDE technique and applicability to the actual components are discussed.

  13. Concomitant formation of different nature clusters and hardening in reactor pressure vessel steels irradiated by heavy ions

    NASA Astrophysics Data System (ADS)

    Fujii, K.; Fukuya, K.; Hojo, T.

    2013-11-01

    Specimens of A533B steels containing 0.04, 0.09 and 0.21 wt%Cu were irradiated at 290 °C to 3 dpa with 3 MeV Fe ions and subjected to atom probe analyses, transmission electron microscopy observations and hardness measurements. The atom probe analysis results showed that two types of solute clusters were formed: Cu-enriched clusters containing Mn, Ni and Si atoms as irradiation-enhanced solute atom clusters and Mn/Ni/Si-enriched clusters as irradiation-induced solute atom clusters. Both cluster types occurred in the highest Cu-content steel and the ratio of Mn/Ni/Si-enriched clusters to Cu-enriched clusters increased with irradiation doses. It was confirmed that the cluster formation was a key factor in the microstructure evolution until the high dose irradiation was reached even in the low Cu content steels though the dislocation loops with much lower density than that of the clusters were observed as matrix damage. The difference in the hardening efficiency due to the difference in the nature of the clusters was small. The irradiation-induced clustering of undersized Si atoms suggested that a clustering driving force other than vacancy-driven diffusion, probably an interstitial mechanism, may become important at higher dose rates.

  14. Investigation on Shielding and Mechanical Behavior of Carbon/Stainless Steel Hybrid Yarn Woven Fabrics and Their Composites

    NASA Astrophysics Data System (ADS)

    Jagatheesan, Krishnasamy; Ramasamy, Alagirusamy; Das, Apurba; Basu, Ananjan

    2017-08-01

    This study investigates the shielding characteristics of carbon/stainless steel/polypropylene (C/SS/PP) hybrid woven fabrics and their composites in low frequency (50 MHz-1.5 GHz) and C band (4-6 GHz) regions. The hybrid yarns prepared from carbon and SS filaments using a direct twisting machine have been made into woven fabric samples using a sample loom. The composite has been made by sandwiching a hybrid yarn fabric between the polypropylene films in a compression molding machine at 180°C for 5 min. The shielding behavior of the fabric and the composites has been tested using a coaxial transmission holder for the low frequency range and a wave guide method for the C band frequency range. It has been observed that a 1 end float composite showed a higher SE of 81.4 dB than the 4 end float (76.2 dB) and the 8 end float composites (64 dB) at the low frequency region. However, at the C band frequency, the effect of fabric structures on shielding effectiveness (SE) of fabric composite depends on thread density. For example, at low thread density, (i.e.) 3.93 ppcm, the 8 end float fabric composite showed the highest SE of 22.7 dB than did the 4 end (20.4 dB) and the 1 end float (16.5 dB) fabric composite. However, at high thread density (6.3 ppcm), the case was the reverse. The 1 end float fabric composite showed the highest SE of 29.7 dB rather than 4 end and 8 end float fabric composites (25.9 dB). In addition, all the composites showed less SE than their fabric forms. The increase in thread density also increased the shielding behavior of composites in both frequency ranges. A nonlinear regression model was developed using the Box-Behnken design for predicting the shielding behavior of fabric composites in C band region. In addition to shielding behavior, mechanical strength of C/SS/PP hybrid yarn, the fabric and composite has been tested using a Zwick Roell tensile tester. It has been observed that the work of rupture of C/SS/PP hybrid yarn is higher (6830.3 g

  15. Investigation of Iron-Chromium-Niobium-Titanium Ferritic Stainless Steel for Solid Oxide Fuel Cell Interconnect Applications

    SciTech Connect

    Yang, Zhenguo; Xia, Guanguang; Wang, Chong M.; Nie, Zimin; Templeton, Joshua D.; Stevenson, Jeffry W.; Singh, Prabhakar

    2008-09-01

    As part of an effort to develop cost-effective ferritic stainless steel-based interconnects for solid oxide fuel cell (SOFC) stacks, AL 441 HPTM was studied in terms of its metallurgical characteristics, oxidation behavior, and electrical performance. Minor alloying elements (Nb and Ti) captured interstitials such as C by forming carbides, stabilizing the ferritic structure and mitigating the risks of sensitization and inter-granular corrosion. Laves phases rich in Nb and Si precipitated along grain boundaries during high temperature exposure, improving the steel’s high temperature mechanical strength. The capture of Si in the Laves phase minimized the Si activity in the steel substrate and prevented formation of an insulating silica layer at the scale/metal interface. However, the relatively high oxidation rate, and thus increasing ASR over time, necessitates the application of a conductive protection layer on the steel. In particular, Mn1.5Co1.5O4 spinel protection layers drastically improved the electrical performance of the ferritic stainless steel 441, acting as barriers to chromium outward and oxygen inward diffusion.

  16. Investigation of iron-chromium-niobium-titanium ferritic stainless steel for solid oxide fuel cell interconnect applications

    NASA Astrophysics Data System (ADS)

    Yang, Zhenguo; Xia, Guan-Guang; Wang, Chong-Min; Nie, Zimin; Templeton, Joshua; Stevenson, Jeffry W.; Singh, Prabhakar

    As part of an effort to develop cost-effective ferritic stainless steel-based interconnects for solid oxide fuel cell (SOFC) stacks, both bare AISI441 and AISI441 coated with (Mn,Co) 3O 4 protection layers were studied in terms of its metallurgical characteristics, oxidation behavior, and electrical performance. The addition of minor alloying elements, in particular Nb, led to formation of Laves phases both inside grains and along grain boundaries. In particular, the Laves phase which precipitated out along grain boundaries during exposure at intermediate SOFC operating temperatures was found to be rich in both Nb and Si. The capture of Si in the Laves phase minimized the Si activity in the alloy matrix and prevented formation of an insulating silica layer at the scale/metal interface, resulting in a reduction in area-specific electrical resistance (ASR). However, the relatively high oxidation rate of the steel, which leads to increasing ASR over time, and the need to prevent volatilization of chromium from the steel necessitates the application of a conductive protection layer on the steel. In particular, the application of a Mn 1.5Co 1.5O 4 spinel protection layer substantially improved the electrical performance of the 441 by reducing the oxidation rate.

  17. Ex-situ and in-situ investigations of thermal anti-oxidation treatments of stainless steels by reflection mode EXAFS

    NASA Astrophysics Data System (ADS)

    Lützenkirchen-Hecht, D.; Wulff, D.; Wagner, R.; Holländer, U.; Maier, HJ; Frahm, R.

    2016-05-01

    Different thermal treatments were performed for the anti-oxidation of steel surfaces, and the processes were investigated ex-situ and in-situ by surface sensitive reflection mode EXAFS experiments at the Cr and Fe K-edges. While the samples for the ex-situ studies were heat-treated in a conveyor belt furnace at temperatures between 600 and 900 °C in inert carrier gases (N2 or Ar) using different additives such as hydrogen (H2) and monosilane (SiH4), the in- situ anti-oxidation treatments have been performed in a high vacuum environment (p < 10-6 mbar). While the ex-situ experiments suggest that SiH4-additives are needed for the reduction of the steel to a metallic state, the in-vacuum treatments appear successful for temperatures above approx. 900 °C.

  18. Mössbauer spectroscopic investigation of retained-austenite content of high-carbon tool steel during isothermal tempering of as-quenched samples

    NASA Astrophysics Data System (ADS)

    Bała, Piotr; Krawczyk, Janusz; Hanc, Aneta

    2009-04-01

    This work presents the results of investigations using Mössbauer spectroscopy technique and their interpretation concerning retained austenite (RA) and its transformation during tempering in relation to previously conducted dilatometric, microscopic and mechanical investigations. This research was conducted on a new high-carbon alloy steel 120 MnCrMoV8-6-4-2, which was designed in 1998, in Phase Transformations Research Group at the AGH UST. The influence of the tempering time on the mechanical and chemical stability of retained austenite and on the products of its transformation, nucleation and solubility of ɛ carbides and cementite nucleation and growth, was determined.

  19. Investigation of Adsorption and Inhibitive Effect of Calixarene Derivative Newly Synthesized Towards C38 Steel in Molar HCl

    NASA Astrophysics Data System (ADS)

    Souane, R.; Kaddouri, M.; Bouklah, M.; Cheriaa, N.; Hammouti, B.; Vicens, J.

    The focus of this study is to synthesize a new calixarene derivative namely calix[6]arene (C21) and to test its performance as corrosion inhibitor of C38 steel in molar HCl at 308 K. Polarization and weight loss measurements were used. Weight loss tests show that C21 retards until to stop corrosion phenomenon at 5 × 10-5 M. C21 is an excellent inhibitor and its inhibition efficiency increases with its concentration to reach 100% since 5 × 10-5 M. Polarization curves revealed that C21 affects both cathodic and anodic domains by decreasing current densities and then it may be classified as a mixed type inhibitor. The calixarene tested is adsorbed on the surface according to the Langmuir adsorption isotherm. Free enthalpy of adsorption reveals that C21 acts from chemisorption onto the steel surface.

  20. Crystallographic investigation of aluminium nitride thin films on stainless steel foil for highly efficient piezoelectric vibration energy harvesters

    NASA Astrophysics Data System (ADS)

    Moriwaki, N.; Minh, L. V.; Ohigashi, R.; Shimada, O.; Kitayoshi, H.; Kuwano, H.

    2016-11-01

    This study reports piezoelectric properties and crystallographic microstructures of aluminium nitride (AlN, wurtzite structure) thin films on 50 μm thick stainless steel foil. The transverse piezoelectric coefficient d31f and e31f of 10 pm thick AlN films were estimated as -1.42 ± 0.08 μm/V and -0.48 ± 0.03 C/m2 from a tip displacement of the piezoelectric cantilevers. Dielectric constant s33 was measured as 10.5 ± 1.0. An electron beam diffraction pattern by a high-resolution transmission electron microscope and x-ray diffraction pattern showed that abundance ratio of the orientation such as <101>, <102> and <103> of AlN crystal on stainless steel foils increased with increasing thickness.

  1. Oxygen diffusion in grain boundaries: a ToF-SIMS investigation on hot-rolled steel sheets.

    PubMed

    Holzweber, Markus; Kriegl, Markus; Schintlmeister, Arno; Paesold, Dieter; Danninger, Herbert; Hutter, Herbert

    2011-05-01

    A study of grain boundary diffusion of oxygen in hot-rolled steel sheets is carried out by means of time-of-flight secondary-ion-mass-spectrometry (ToF-SIMS). This involves polishing of the sample surface prior to the oxygen exposure. A nickel layer deposited after exposure ensures a homogeneous extraction field for ToF-SIMS measurements at the Ni-steel interface. The sample is bevelled at an angle of 11.5° to spread up the diffusion pathway by a factor of 5. The oxygen distribution is then acquired via ToF-SIMS in imaging mode from which diffusion parameters are calculated according to the Whipple-Le Claire's approach.

  2. Experimental investigation of the effect of the material damage induced in sheet metal forming process on the service performance of 22MnB5 steel

    NASA Astrophysics Data System (ADS)

    Zhuang, Weimin; Xie, Dongxuan; Chen, Yanhong

    2016-07-01

    The use of ultra-high strength steels through sheet metal forming process offers a practical solution to the lightweight design of vehicles. However, sheet metal forming process not only produces desirable changes in material properties but also causes material damage that may adversely influence the service performance of the material formed. Thus, an investigation is conducted to experimentally quantify such influence for a commonly used steel (the 22MnB5 steel) based on the hot and cold forming processes. For each process, a number of samples are used to conduct a uniaxial tensile test to simulate the forming process. After that, some of the samples are trimmed into a standard shape and then uniaxially extended until fracture to simulate the service stage. Finally, a microstructure test is conducted to analyze the microdefects of the remaining samples. Based on the results of the first two tests, the effect of material damage on the service performance of 22MnB5 steel is analyzed. It is found that the material damages of both the hot and cold forming processes cause reductions in the service performance, such as the failure strain, the ultimate stress, the capacity of energy absorption and the ratio of residual strain. The reductions are generally lower and non-linear in the former process but higher and linear in the latter process. Additionally, it is found from the microstructure analysis that the difference in the reductions of the service performance of 22MnB5 by the two forming processes is driven by the difference in the micro damage mechanisms of the two processes. The findings of this research provide a useful reference in terms of the selection of sheet metal forming processes and the determination of forming parameters for 22MnB5.

  3. Experimental und numerical investigations on cooling efficiency of Air-Mist nozzles on steel during continuous casting

    NASA Astrophysics Data System (ADS)

    Arth, G.; Taferner, M.; Bernhard, C.; Michelic, S.

    2016-07-01

    Cooling strategies in continuous casting of steel can vary from rapid cooling to slow cooling, mainly controlled by adjusting the amount of water sprayed onto the surface of the product. Inadequate adjustment however can lead to local surface undercooling or reheating, leading to surface and inner defects. This paper focuses on cooling efficiency of Air-Mist nozzles on casted steel and the experimental and numerical prediction of surface temperature distributions over the product width. The first part explains the determination of heat transfer coefficients (HTC) on laboratory scale, using a so called nozzle measuring stand (NMS). Based on measured water distributions and determined HTC's for air-mist nozzles using the NMS, surface temperatures are calculated by a transient 2D-model on a simple steel plate, explained in the second part of this paper. Simulations are carried out varying water impact density and spray water distribution, consequently influencing the local HTC distribution over the plate width. Furthermore, these results will be interpreted with regard to their consequence for surface and internal quality of the cast product. The results reveal the difficulty of correct adjustment of the amount of sprayed water, concurrent influencing water distribution and thus changing HTC distribution and surface temperature.

  4. An Investigation of Over-Heating and Rock-Like Fracture of Steel 18Cr2Ni4WA

    DTIC Science & Technology

    1979-06-29

    basic electric process; and electric proce ss plusL eletri slg rmelinq) an-’ two dill’erent m~ethods of’ deoxidization ( using alminum and titaniun or...fain of -11 gr--ains 3reci-Oitates at austenite -rain boundary. It is believed th-a .idization by-, us ~r.ng both alzumintum and A .tanium can make the...the mechanism of’ this steel which heins to form rock- like fracturAe is brouc-ht in-to discussion. When teel l~G2!4Amle by electric process (and

  5. Effects of chemical composition and dose on microstructure evolution and hardening of neutron-irradiated reactor pressure vessel steels

    NASA Astrophysics Data System (ADS)

    Takeuchi, T.; Kuramoto, A.; Kameda, J.; Toyama, T.; Nagai, Y.; Hasegawa, M.; Ohkubo, T.; Yoshiie, T.; Nishiyama, Y.; Onizawa, K.

    2010-07-01

    The correlation of microstructure evolution and hardening was studied in two kinds of A533B-1 steel with high and low levels of Cu irradiated in a range of dose from 0.32 to 9.9 × 10 19 n cm -2 ( E > 1 MeV) under a high flux of about 1.7 × 10 13 n cm -2 s -1 using three-dimensional local electrode atom probe (3DAP), positron annihilation (PA) techniques, and Vickers microhardness. The early rapid hardening was found to be caused by mainly matrix defects such as mono- or di-vacancies ( V1 - V2) and/or dislocations indicated by the PA analysis. The 3DAP analysis showed that dense dispersion of dilute Cu rich clusters and lean distribution of Mn-Ni-Si rich clusters, which were identified to possess the same dislocation-pinning effect by applying a Russell and Brown model, were responsible for large and small hardening in high- and low-Cu steels irradiated above 0.59 × 10 19 n cm 2, respectively.

  6. Investigation on the application of steel slag-fly ash-phosphogypsum solidified material as road base material.

    PubMed

    Shen, Weiguo; Zhou, Mingkai; Ma, Wei; Hu, Jinqiang; Cai, Zhi

    2009-05-15

    The aim of the present work is to prepare a new type of steel slag-fly ash-phosphogypsum solidified material totally composed with solid wastes to be utilized as road base material. The mix formula of this material was optimized, the solidified material with optimal mix formula (fly ash/steel slag=1:1, phosphogypsum dosage=2.5%) results in highest strength. The strength development, resilience modulus and splitting strength of this material were studied comparing with some typical road base materials, the 28- and 360-day strength of this material can reach 8MPa and 12MPa, respectively, its resilience modulus reaches 1987MPa and splitting strength reaches 0.82MPa, it has higher early strength than lime-fly ash and lime-soil road base material, its long-term strength is much higher than cement stabilized granular materials, the solidified material has best water stability among those road base materials, it can be engineered as road base material with competitive properties. The strength formation mechanism of this solidified material is discussed also.

  7. Investigation of the Phase Formation of AlSi-Coatings for Hot Stamping of Boron Alloyed Steel

    SciTech Connect

    Veit, R.; Kolleck, R.; Hofmann, H.; Sikora, S.

    2011-01-17

    Hot stamping of boron alloyed steel is gaining more and more importance for the production of high strength automotive body parts. Within hot stamping of quenchenable steels the blank is heated up to austenitization temperature, transferred to the tool, formed rapidly and quenched in the cooled tool. To avoid scale formation during the heating process of the blank, the sheet metal can be coated with an aluminium-silicum alloy. The meltimg temperature of this coating is below the austenitization temperature of the base material. This means, that a diffusion process between base material and coating has to take place during heating, leading to a higher melting temperature of the coating.In conventional heating devices, like roller hearth furnaces, the diffusion process is reached by relatively low heating rates. New technologies, like induction heating, reach very high heating rates and offer great potentials for the application in hot stamping. Till now it is not proofed, that this technology can be used with aluminum-silicon coated materials. This paper will present the results of comparative heating tests with a conventional furnace and an induction heating device. For different time/temperature-conditions the phase formation within the coating will be described.

  8. Investigation of the Phase Formation of AlSi-Coatings for Hot Stamping of Boron Alloyed Steel

    NASA Astrophysics Data System (ADS)

    Veit, R.; Hofmann, H.; Kolleck, R.; Sikora, S.

    2011-01-01

    Hot stamping of boron alloyed steel is gaining more and more importance for the production of high strength automotive body parts. Within hot stamping of quenchenable steels the blank is heated up to austenitization temperature, transferred to the tool, formed rapidly and quenched in the cooled tool. To avoid scale formation during the heating process of the blank, the sheet metal can be coated with an aluminium-silicum alloy. The meltimg temperature of this coating is below the austenitization temperature of the base material. This means, that a diffusion process between base material and coating has to take place during heating, leading to a higher melting temperature of the coating. In conventional heating devices, like roller hearth furnaces, the diffusion process is reached by relatively low heating rates. New technologies, like induction heating, reach very high heating rates and offer great potentials for the application in hot stamping. Till now it is not proofed, that this technology can be used with aluminum-silicon coated materials. This paper will present the results of comparative heating tests with a conventional furnace and an induction heating device. For different time/temperature-conditions the phase formation within the coating will be described.

  9. In situ x-ray diffraction investigations during low energy ion nitriding of austenitic stainless steel grade 1.4571

    NASA Astrophysics Data System (ADS)

    Manova, D.; Mändl, S.; Gerlach, J. W.; Hirsch, D.; Neumann, H.; Rauschenbach, B.

    2014-09-01

    Insertion of nitrogen into austenitic stainless steel leads to anomalously fast nitrogen diffusion and the formation of an expanded face-centred cubic phase which is known to contain a large amount of mechanical stress. In situ x-ray diffraction (XRD) measurements during low energy nitrogen ion implantation into steel 316Ti at 300-550 °C allow a direct view into diffusion and phase formation. While the layer growth is directly observable from the decreasing substrate reflection intensity, the time evolution of the intensities for the expanded phase reflection is much more complex: several mechanisms including at least formation and annealing of defects, twinning, reduction of the crystal symmetry, or grain rotation may be active inside the expanded phase, besides the thermally activated decay of the metastable expanded phase. This locally varying coherence length or scattering intensity from the expanded phase is furthermore a function of temperature and time, additionally complicating the deconvolution of XRD spectra for stress and concentration gradients. As no concise modelling of this coherence length is possible at present, a simple qualitative model assuming a dependence of the scattering intensity on the depth, influence by stress and plastic flow during the nitriding process is proposed for understanding the underlying processes.

  10. Influence of the copper impurity level on the irradiation response of reactor pressure vessel steels investigated by SANS

    NASA Astrophysics Data System (ADS)

    Wagner, Arne; Ulbricht, Andreas; Bergner, Frank; Altstadt, Eberhard

    2012-06-01

    Reactor pressure vessel (RPV) steel, when exposed to neutron irradiation, induces the formation of nano-sized features. Using small angle neutron scattering (SANS) we have studied the neutron fluence dependence of the precipitate volume fraction for high-Cu and low-Cu materials separately. Cu-rich precipitates have long been recognized to play the dominant role in embrittlement of Cu-bearing RPV steels. In contrast, Mn-Ni-rich precipitates seem to govern embrittlement in the case of low levels of impurity Cu. The objective is to work out the resulting differences from the microstructural point of view. For low-Cu materials, the volume fraction was found to be within the detection limit of SANS at fluences below an apparent threshold fluence, whereas the slope increases considerably beyond. The relationship between irradiation-induced yield stress increase and precipitate volume fraction was also considered. We have derived estimates of the obstacle strength for Cu-rich precipitates and for Mn-Ni-rich precipitates.

  11. An in-situ SERS investigation of the passive film on stainless steel at high temperature in pressurized water

    NASA Astrophysics Data System (ADS)

    Kumai, Christopher Shigeki

    2000-10-01

    An in situ study of the films formed on stainless steel at 288°C was performed using Surface Enhanced Raman Spectroscopy (SERS). By monitoring changes in the structure of the film as the interface potential of the sample changed, it was possible to suggest how the surface film affects Intergranular Stress Corrosion Cracking (IGSCC). Samples included 304 stainless steel, chromium depleted alloys, iron, nickel, and chromium. Observations of the films on iron, nickel, and chromium were compared to calculated Pourbaix diagrams. All of the iron based samples were found to passivate by the formation of alpha-Fe2O3 at --400 mV SHE. Below this potential, the surface film consisted of Fe3O4. On the iron-chromium alloys, gamma-Fe2O3 was found to form at intermediate interface potentials. These results suggest a reason for the well-known observation that IGSCC only occurs at potentials above --230 mV. Namely, when the potential outside the crack is --230 mV, the potential at the tip of the intergranular stress corrosion crack is --400 mV, the value above which all iron base alloys regardless of their chromium concentration are passive. Decreased chromium concentrations decreased the ability of alpha-Fe 2O3 and Fe3O4 to protect the sample. In addition, decreased chromium concentrations increased the potential at which gamma-Fe2O3 formed. Ex situ scanning electron microscopy was used to show that the films formed on the iron based samples were a double layer film consisting of an inner layer of conformal Fe3O4 and an outer layer of ˜1um sized grains of Fe3O4. Upon passivation, the alpha-Fe 2O3 formed a thin layer over all surfaces. The transformation of Fe3O4 to alpha-Fe2O3 takes place by a solid state reaction. The majority of outer layer formation occurred before the formation of the passivating alpha-Fe2O3 layer. Growth of the outer layer is limited by the electrochemical reduction at the film/water interface and not by transport of iron cations through the inner layer of

  12. Changes in electromagnetic properties of a low-alloy steel caused by neutron irradiation

    SciTech Connect

    Goto, Toru; Kamimura, Takeo; Kumano, Shintaro; Takeuchi, Iwao; Maeda, Noriyoshi; Yamaguchi, Atsunori

    1999-10-01

    In order to develop a method for the nondestructive evaluation of material deterioration in nuclear pressure vessels, changes in the electromagnetic properties of the low-alloy steel A533B, Class 1 and its weld metal caused by neutron irradiation up to {approximately}3 {times} 10{sup 23} n/m{sup 2} of neutron fluence at 561 K were measured. Electrical resistance, coercivity and Barkhausen noise were selected as the electromagnetic properties to measure. It was found that decreases of several percent in the readings of electrical resistance and coercivity, and an increase of several percent in the Barkhausen noise occurred due to neutron irradiation. Good correlations between the changes in the electromagnetic properties and those in the mechanical properties were confirmed. Furthermore, an equation using the results of the three tests was found to estimate well the transition temperature and yield strength. From this, the authors conclude that the electromagnetic tests have potential as methods for nondestructive evaluation of material deterioration in the reactor vessels of nuclear power plants.

  13. Detection of radiation damage in low alloy steel using a SQUID sensor

    SciTech Connect

    Otaka, Masahiro; Shimizu, Sadato; Morinaka, Ren; Maeda, Noriyoshi; Yamaguchi, Atsunori

    1999-10-01

    The magnetic properties of A533B low alloy steel irradiated up to 3 {times} 10{sup 23} n/m{sup 2} in a nuclear reactor were measured using a SQUID sensor. The SQUID sensor used in the test is the type with a first-order axial gradiometer. Test specimens were irradiated to 0.5 {times} 10{sup 23} and 3.0 {times} 10{sup 23} n/m{sup 2}, and then magnetized in a 0.2 T field until saturation before measurement. The specimens were put on a scanning table in a hot laboratory and the SQUID output was recorded while each specimen was gradually moved in a horizontal direction under the SQUID sensor. A superconducting magnet was used to put the test specimen under a magnetic field that changed from +0.01 T to {minus}0.01 T to observe the relation between magnetic field intensity and coercive force (B-H curve). The B-H curve shows a definite tendency towards a higher coercive force for test specimens with higher neutron fluence. The test result also shows a good relation between mechanical properties, such as yield strength, tensile strength, and the Charpy impact test result, with SQUID output. This proves that there is a very good change of developing a non-destructive evaluation system for nuclear reactor structure. This kind of evaluation system would be a great help in making plant life management even more reliable and reasonable.

  14. Atomic scale investigation of redistribution of alloying elements in pearlitic steel wires upon cold-drawing and annealing.

    PubMed

    Li, Y J; Choi, P; Goto, S; Borchers, C; Raabe, D; Kirchheim, R

    2013-09-01

    A local electrode atom probe has been employed to analyze the redistribution of alloying elements including Si, Mn, and Cr in pearlitic steel wires upon cold-drawing and subsequent annealing. It has been found that the three elements undergo mechanical mixing upon cold-drawing at large strains, where Mn and Cr exhibit a nearly homogeneous distribution throughout both ferrite and cementite, whereas Si only dissolves slightly in cementite. Annealing at elevated temperatures leads to a reversion of the mechanical alloying. Si atoms mainly segregate at well-defined ferrite (sub)grain boundaries formed during annealing. Cr and Mn are strongly concentrated in cementite adjacent to the ferrite/cementite interface due to their lower diffusivities in cementite than in ferrite. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Experimental Investigation of Machining AISI 1040 Medium Carbon Steel Under Cryogenic Machining: A Comparison with Dry Machining

    NASA Astrophysics Data System (ADS)

    Gupta, Munish Kumar; Singh, Gauravdeep; Sood, Pardeep Kumar

    2015-10-01

    This experimental work was carried out by turning of AISI 1040 medium carbon steel in which the effect of cryogenic cooling (LN2) used as a cutting fluid is compared to that of dry machining with respect to tool wear i.e. crater and flank wear, surface roughness, cutting forces (feed and cutting forces) and cutting temperature. Experiments were performed using uncoated tungsten carbide insert tool having various feed rate and constant cutting speed. Compared to dry machining, in LN2 machining, overall the tool wear were reduced to 55.45 and 65.53 %, surface roughness was reduced to 125.90 % and forces were reduced to 61.94 and 96.60 %. The experimental results proved that the application of cryogenic coolant overall increases the machining performance as compared to dry machining.

  16. Microstructure Investigation of 13Cr-2Mo ODS Steel Components Obtained by High Voltage Electric Discharge Compaction Technique

    PubMed Central

    Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; Chernov, Ivan; Staltsov, Maxim; Khasanov, Oleg; Olevsky, Eugene

    2015-01-01

    Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining the initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. The choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality. PMID:28793641

  17. TEM and AES investigations of the natural surface nano-oxide layer of an AISI 316L stainless steel microfibre.

    PubMed

    Ramachandran, Dhanya; Egoavil, Ricardo; Crabbe, Amandine; Hauffman, Tom; Abakumov, Artem; Verbeeck, Johan; Vandendael, Isabelle; Terryn, Herman; Schryvers, Dominique

    2016-11-01

    The chemical composition, nanostructure and electronic structure of nanosized oxide scales naturally formed on the surface of AISI 316L stainless steel microfibres used for strengthening of composite materials have been characterised using a combination of scanning and transmission electron microscopy with energy-dispersive X-ray, electron energy loss and Auger spectroscopy. The analysis reveals the presence of three sublayers within the total surface oxide scale of 5.0-6.7 nm thick: an outer oxide layer rich in a mixture of FeO.Fe2 O3 , an intermediate layer rich in Cr2 O3 with a mixture of FeO.Fe2 O3 and an inner oxide layer rich in nickel.

  18. An Investigation Utilizing an Electrical Analogue of Cyclic Deicing of Hollow Steel Propellers with Internal Electric Heaters

    NASA Technical Reports Server (NTRS)

    Neel, Carr B., Jr.

    1953-01-01

    A study has been made of the heating requirements for the cyclic de?icing of hollow steel propellers fitted with two types of internal electric heaters. Solutions to the transient?teat?flow equations depicting the cyclic de?icing of propellers were obtained by use of an electrical analogy. The study showed the impracticability of using an internal tubular heater and illustrated the advantages of employing an internal shoe?type heater, which distributes the heat more evenly to the blade surface. The importance of minimizing the thermal inertia of the system was demonstrated, and the magnitude of reductions in the total energy requirement made possible through reductions in the heating period was indicated.

  19. Microstructure investigation of 13Cr-2Mo ODS steel components obtained by high voltage electric discharge compaction technique

    SciTech Connect

    Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; Chernov, Ivan; Staltsov, Maxim; Khasanov, Oleg; Olevsky, Eugene

    2015-11-02

    Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining the initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. As a result, the choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.

  20. Ballistic-Failure Mechanisms in Gas Metal Arc Welds of Mil A46100 Armor-Grade Steel: A Computational Investigation

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Snipes, J. S.; Galgalikar, R.; Ramaswami, S.; Yavari, R.; Yen, C.-F.; Cheeseman, B. A.

    2014-09-01

    In our recent work, a multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process was introduced. The model is of a modular type and comprises five modules, each designed to handle a specific aspect of the GMAW process, i.e.: (i) electro-dynamics of the welding-gun; (ii) radiation-/convection-controlled heat transfer from the electric-arc to the workpiece and mass transfer from the filler-metal consumable electrode to the weld; (iii) prediction of the temporal evolution and the spatial distribution of thermal and mechanical fields within the weld region during the GMAW joining process; (iv) the resulting temporal evolution and spatial distribution of the material microstructure throughout the weld region; and (v) spatial distribution of the as-welded material mechanical properties. In the present work, the GMAW process model has been upgraded with respect to its predictive capabilities regarding the spatial distribution of the mechanical properties controlling the ballistic-limit (i.e., penetration-resistance) of the weld. The model is upgraded through the introduction of the sixth module in the present work in recognition of the fact that in thick steel GMAW weldments, the overall ballistic performance of the armor may become controlled by the (often inferior) ballistic limits of its weld (fusion and heat-affected) zones. To demonstrate the utility of the upgraded GMAW process model, it is next applied to the case of butt-welding of a prototypical high-hardness armor-grade martensitic steel, MIL A46100. The model predictions concerning the spatial distribution of the material microstructure and ballistic-limit-controlling mechanical properties within the MIL A46100 butt-weld are found to be consistent with prior observations and general expectations.

  1. A randomized clinical trial investigating pain associated with superelastic nickel–titanium and multistranded stainless steel archwires during the initial leveling and aligning phase of orthodontic treatment

    PubMed Central

    Sandhu, Satpal Singh; Sandhu, Jasleen

    2013-01-01

    Objective:To investigate and compare the effects of superelastic nickel–titanium and multistranded stainless steel archwires on pain during the initial phase of orthodontic treatment. Design:A double-blind two-arm parallel design stratified randomized clinical trial. Setting:A single centre in India between December 2010 and June 2012. A total of 96 participants (48 male and 48 females; 14.1±2.1 years old) were randomized (stratified on age, sex and initial crowding) to superelastic nickel–titanium or multistranded stainless steel archwire groups using a computer-generated allocation sequence. Methods:We compared 0.016-inch superelastic nickel–titanium and 0.0175-inch multistranded stainless steel wires in 0.022-inch slot (Roth prescription) preadjusted edgewise appliances. The follow-up period was 14 days. Outcome was assessed with a visual analogue scale at baseline and 32 pre-specified follow-up points. Data was analyzed using mixed-effects model analysis. Results:One participant was lost to follow up and 10 were excluded from the analysis due to bond failure or incomplete questionnaire answers. Ultimately, 85 participants (42 males and 43 females; 14.1±2.0 years old) were analysed for the final results. No statistically significant difference was found for overall pain [F value = 2.65, degrees of freedom (df) = 92.6; P = 0.1071]. However, compared to multistranded stainless steel wires, pain in subjects with superelastic nickel–titanium archwires was significantly greater at 12 h (t = 2.34; P = 0.0193), as well as at day 1 in the morning (t = 2.21, P = 0.0273), afternoon (t = 2.11, P = 0.0346) and at bedtime (t = 2.03, P = 0.042). Conclusion:For overall pain, there was no statistically significant difference between the two wires. However, subjects with superelastic nickel–titanium archwires had a significantly higher pain at peak level. PMID:24297959

  2. A Novel Emulsion Flow Loop for Investigating the Corrosion of X65 Steel in Emulsions with H2S/CO2

    NASA Astrophysics Data System (ADS)

    Rihan, Rihan; Zafar, Muhammad Nauman; Al-Hadhrami, Luai

    2016-07-01

    Corrosion resistance ( R P) of X65 steel was investigated in an oil-in-water emulsion containing H2S and CO2 at several oil concentrations and different flow regions using a novel emulsion flow loop. One working electrode was mounted in the flow developing region while the other one was mounted in a region where the flow is fully developed. The experimental results show that the addition of CO2 to an H2S containing emulsion decreases the corrosion rate. The R P in the flow developing region is less than that in the fully developed region and it increases with increasing oil concentration. This flow loop is a promising tool for investigating the R P of engineering materials in a simulated environment similar to that encountered in the petroleum industry.

  3. Nuclear transmutation in steels

    NASA Astrophysics Data System (ADS)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  4. Enabling Inexpensive Metallic Alloys as SOFC Interconnects: An Investigation into Hybrid Coating Technologies to Deposit Nanocomposite Functional Coatings on Ferritic Stainless Steel

    SciTech Connect

    Gannon, Paul; Gorokhovsky, Vladimir I.; Deibert, Max; Smith, Richard J.; Kayani, Asghar N.; White, P T.; Sofie, Stephen W.; Yang, Z Gary; Mccready, David E.; Visco, S.; Jacobson, C.; Kurokawa, H.

    2007-11-01

    Reduced operating temperatures (600-800°C) of Solid Oxide Fuel Cells (SOFCs) may enable the use of inexpensive ferritic steels as interconnects. Due to the demanding SOFC interconnect operating environment, protective coatings are required to increase long-term stability. In this study, large area filtered arc deposition (LAFAD) and hybrid filtered arc-assisted electron beam physical vapor deposition (FA-EBPVD) technologies were used to deposit two-segment coatings with Cr-Al-Y-O nanocomposite bottom segments and Mn-Co-O spinel-based top segments. Coatings were deposited on ferritic steels and subsequently annealed in air for various times. Surface oxidation was investigated using SEM/EDS, XRD and RBS analyses. Cr-volatilization was evaluated by transpiration and ICP-MS analysis of the resultant condensate. Time dependent Area Specific Resistance (ASR) was studied using the four-point technique. The oxidation behavior, Cr volatilization rate, and ASR of coated and uncoated samples are reported. Significant long-term (>1,000 hours) surface stability, low ASR, and dramatically reduced Cr-volatility were observed with the coated specimens. Improvement mechanisms, including the coating diffusion barrier properties and electrical conductivity are discussed.

  5. Investigation into the diffusion and oxidation behavior of the interface between a plasma-sprayed anode and a porous steel support for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Zhang, Shan-Lin; Li, Cheng-Xin; Li, Chang-Jiu; Liu, Meilin; Yang, Guan-Jun

    2016-08-01

    Porous metal-supported solid oxide fuel cells (SOFCs) have attracted much attention because their potential to dramatically reduce the cost while enhancing the robustness and manufacturability. In particular, 430 ferritic steel (430L) is one of the popular choice for SOFC support because of its superior performance and low cost. In this study, we investigate the oxidation and diffusion behavior of the interface between a Ni-based anode and porous 430L support exposed to a humidified (3% H2O) hydrogen atmosphere at 700 °C. The Ni-GDC (Ce0.8Gd0.2O2-δ) cermet anodes are deposited on the porous 430L support by atmospheric plasma spraying (APS). The effect of exposure time on the microstructure and phase structure of the anode and the supports is studied and the element diffusion across the support/anode interface is characterized. Results indicate that the main oxidation product of the 430L support is Cr2O3, and that Cr and Fe will diffuse to the anode and the diffusion thickness increases with the exposure time. The diffusion thickness of Cr and Fe reach about 5 and 2 μm, respectively, after 1000 h exposure. However, the element diffusion and oxidation has little influence on the area-specific resistance, indicating that the porous 430L steel and plasma sprayed Ni-GDC anode are promising for durable SOFCs.

  6. Investigations on the Behavior of HVOF and Cold Sprayed Ni-20Cr Coating on T22 Boiler Steel in Actual Boiler Environment

    NASA Astrophysics Data System (ADS)

    Bala, Niraj; Singh, Harpreet; Prakash, Satya; Karthikeyan, J.

    2012-01-01

    High temperature corrosion accompanied by erosion is a severe problem, which may result in premature failure of the boiler tubes. One countermeasure to overcome this problem is the use of thermal spray protective coatings. In the current investigation high velocity oxy-fuel (HVOF) and cold spray processes have been used to deposit commercial Ni-20Cr powder on T22 boiler steel. To evaluate the performance of the coatings in actual conditions the bare as well as the coated steels were subjected to cyclic exposures, in the superheater zone of a coal fired boiler for 15 cycles. The weight change and thickness loss data were used to establish kinetics of the erosion-corrosion. X-ray diffraction, surface and cross-sectional field emission scanning electron microscope/energy dispersive spectroscopy (FE-SEM/EDS) and x-ray mapping techniques were used to analyse the as-sprayed and corroded specimens. The HVOF sprayed coating performed better than its cold sprayed counterpart in actual boiler environment.

  7. Coupled Multi-Electrode Investigation of Crevice Corrosion of 316 Stainless Steel and NiCrMo Alloy 625

    SciTech Connect

    F. Bocher; F.J. Presuel-Moreno; J.R. Scully

    2006-06-08

    the position where the potential drops to E{sub Flade}. Figure 1 illustrates the resulting x{sub crit} vs. G scaling laws for 316 Stainless Steel in 1 M HCl at 50 C. The coupled multi-wire array is composed of one hundred identical 316 Stainless Steel wires in a five by twenty formation inserted in a groove of a 316 Stainless Steel rod such that the ends of the wires are flush mounted with the rod. The 100 wires are coupled electrically through in-line zero resistance ammeters. The diameter of the wires (250 {micro}m) was chosen so that x{sub crit} (critical initiation distance from the crevice mouth) and the expected zone of crevice corrosion (predicted from the scaling law) would be larger than the radius of a single wire. The array created a flush mounted planar electrode with the surface/volume ratio obtained in planar crevices. The observation of the current evolution as a function of position inside and outside the crevice as function of time was made possible as illustrated in Figure 2 in 0.6 M NaCl at 50 C.

  8. Aircraft Steels

    DTIC Science & Technology

    2009-02-19

    NAWCADPAX/TR-2009/ 12 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders 19 February 2009...MARYLAND NAWCADPAX/TR-2009/ 12 19 February 2009 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders...Prescribed by ANSI Std. Z39-18 NAWCADPAX/TR-2009/ 12 ii SUMMARY Five high strength and four stainless steels have been studied, identifying their

  9. An investigation of the antibacterial ability and cytotoxicity of a novel cu-bearing 317L stainless steel

    PubMed Central

    Sun, Da; Xu, Dake; Yang, Chunguang; Shahzad, M. Babar; Sun, Ziqing; Xia, Jin; Zhao, Jinlong; Gu, Tingyue; Yang, Ke; Wang, Guixue

    2016-01-01

    In order to solve the challenging problem of microbial infections caused by microorganisms on medical implants, it is imperative to develop novel antimicrobial biomaterials. This work demonstrated that 317L-Cu stainless steel (SS), created by adding copper through a solution and aging heat treatment process, exhibited good antibacterial properties against staphylococcus aureus, achieving 2 log reduction of planktonic cells after 5 days of incubation. In this study, the antibacterial test was performed using the plate count method, the fluorescence cell staining method and the quantitative polymerase chain reaction (qPCR) method. It is well known that a high concentration of copper ion can lead to cytotoxicity. This work explored the cytotoxicity of 317L-Cu SS through real-time cell analysis (RTCA). Experimental results demonstrated that the 317L-Cu SS possessed a satisfactory antibacterial ability against S. aureus, and the antibacterial rate based on the reduction of sessile cell count reached 98.3% after 24-hour treatment. The bacterial adhesion and the biofilm thickness were considerably reduced by the 317L-Cu SS. The results of RTCA suggested that 317L-Cu SS did not introduce cytotoxicity to mouse cells, indicating its suitability as a medical implant material. PMID:27385507

  10. An investigation of the antibacterial ability and cytotoxicity of a novel cu-bearing 317L stainless steel

    NASA Astrophysics Data System (ADS)

    Sun, Da; Xu, Dake; Yang, Chunguang; Shahzad, M. Babar; Sun, Ziqing; Xia, Jin; Zhao, Jinlong; Gu, Tingyue; Yang, Ke; Wang, Guixue

    2016-07-01

    In order to solve the challenging problem of microbial infections caused by microorganisms on medical implants, it is imperative to develop novel antimicrobial biomaterials. This work demonstrated that 317L-Cu stainless steel (SS), created by adding copper through a solution and aging heat treatment process, exhibited good antibacterial properties against staphylococcus aureus, achieving 2 log reduction of planktonic cells after 5 days of incubation. In this study, the antibacterial test was performed using the plate count method, the fluorescence cell staining method and the quantitative polymerase chain reaction (qPCR) method. It is well known that a high concentration of copper ion can lead to cytotoxicity. This work explored the cytotoxicity of 317L-Cu SS through real-time cell analysis (RTCA). Experimental results demonstrated that the 317L-Cu SS possessed a satisfactory antibacterial ability against S. aureus, and the antibacterial rate based on the reduction of sessile cell count reached 98.3% after 24-hour treatment. The bacterial adhesion and the biofilm thickness were considerably reduced by the 317L-Cu SS. The results of RTCA suggested that 317L-Cu SS did not introduce cytotoxicity to mouse cells, indicating its suitability as a medical implant material.

  11. Investigation of Effect of Pre-Strain on Very High-Cycle Fatigue Strength of Austenitic Stainless Steels

    NASA Astrophysics Data System (ADS)

    Ogawa, Takeshi; Nakane, Motoki; Masaki, Kiyotaka; Hashimoto, Shota; Ochi, Yasuo; Asano, Kyoichi

    This paper describes the effect of large pre-strain on very high cycle fatigue strength of austenitic stainless steels that are widely used in nuclear power plants. Fatigue tests were carried out on strain-hardened specimens. The material served in this study was type SUS316NG. Up to ±20% pre-strain was introduced to the materials, and the materials were mechanically machined into hourglass shaped smooth specimens. Some specimens were pre-strained after machining. Experiments were conducted in ultrasonic and rotating-bending fatigue testing machines. The S-N curves obtained in this study show that an increase in the magnitude of the pre-strain increases the fatigue strength of the material and this relationship is independent of the type of the pre-strain of tension or compression. Although all specimens fractured by the surface initiated fatigue cracks, one specimen fractured by an internal origin. However, this internal fracture did not cause a sudden drop in fatigue strength of type SUS316NG. Vickers hardness tests were carried out to ascertain the relationship between fatigue strength and hardness of the pre-strained materials. It was found that the increase in the fatigue limit of the pre-strained materials strongly depended on the hardness derived from an indentation size equal to the scale of stage I fatigue cracks.

  12. A Review of Natural Joint Systems and Numerical Investigation of Bio-Inspired GFRP-to-Steel Joints

    PubMed Central

    Avgoulas, Evangelos I.; Sutcliffe, Michael P. F.

    2016-01-01

    There are a great variety of joint types used in nature which can inspire engineering joints. In order to design such biomimetic joints, it is at first important to understand how biological joints work. A comprehensive literature review, considering natural joints from a mechanical point of view, was undertaken. This was used to develop a taxonomy based on the different methods/functions that nature successfully uses to attach dissimilar tissues. One of the key methods that nature uses to join dissimilar materials is a transitional zone of stiffness at the insertion site. This method was used to propose bio-inspired solutions with a transitional zone of stiffness at the joint site for several glass fibre reinforced plastic (GFRP) to steel adhesively bonded joint configurations. The transition zone was used to reduce the material stiffness mismatch of the joint parts. A numerical finite element model was used to identify the optimum variation in material stiffness that minimises potential failure of the joint. The best bio-inspired joints showed a 118% increase of joint strength compared to the standard joints. PMID:28773688

  13. An investigation of the antibacterial ability and cytotoxicity of a novel cu-bearing 317L stainless steel.

    PubMed

    Sun, Da; Xu, Dake; Yang, Chunguang; Shahzad, M Babar; Sun, Ziqing; Xia, Jin; Zhao, Jinlong; Gu, Tingyue; Yang, Ke; Wang, Guixue

    2016-07-07

    In order to solve the challenging problem of microbial infections caused by microorganisms on medical implants, it is imperative to develop novel antimicrobial biomaterials. This work demonstrated that 317L-Cu stainless steel (SS), created by adding copper through a solution and aging heat treatment process, exhibited good antibacterial properties against staphylococcus aureus, achieving 2 log reduction of planktonic cells after 5 days of incubation. In this study, the antibacterial test was performed using the plate count method, the fluorescence cell staining method and the quantitative polymerase chain reaction (qPCR) method. It is well known that a high concentration of copper ion can lead to cytotoxicity. This work explored the cytotoxicity of 317L-Cu SS through real-time cell analysis (RTCA). Experimental results demonstrated that the 317L-Cu SS possessed a satisfactory antibacterial ability against S. aureus, and the antibacterial rate based on the reduction of sessile cell count reached 98.3% after 24-hour treatment. The bacterial adhesion and the biofilm thickness were considerably reduced by the 317L-Cu SS. The results of RTCA suggested that 317L-Cu SS did not introduce cytotoxicity to mouse cells, indicating its suitability as a medical implant material.

  14. Microstructure investigation of 13Cr-2Mo ODS steel components obtained by high voltage electric discharge compaction technique

    DOE PAGES

    Bogachev, Igor; Yudin, Artem; Grigoryev, Evgeniy; ...

    2015-11-02

    Refractory oxide dispersion strengthened 13Cr-2Mo steel powder was successfully consolidated to near theoretical density using high voltage electric discharge compaction. Cylindrical samples with relative density from 90% to 97% and dimensions of 10 mm in diameter and 10–15 mm in height were obtained. Consolidation conditions such as pressure and voltage were varied in some ranges to determine the optimal compaction regime. Three different concentrations of yttria were used to identify its effect on the properties of the samples. It is shown that the utilized ultra-rapid consolidation process in combination with high transmitted energy allows obtaining high density compacts, retaining themore » initial structure with minimal grain growth. The experimental results indicate some heterogeneity of the structure which may occur in the external layers of the tested samples due to various thermal and electromagnetic in-processing effects. As a result, the choice of the optimal parameters of the consolidation enables obtaining samples of acceptable quality.« less

  15. A Review of Natural Joint Systems and Numerical Investigation of Bio-Inspired GFRP-to-Steel Joints.

    PubMed

    Avgoulas, Evangelos I; Sutcliffe, Michael P F

    2016-07-12

    There are a great variety of joint types used in nature which can inspire engineering joints. In order to design such biomimetic joints, it is at first important to understand how biological joints work. A comprehensive literature review, considering natural joints from a mechanical point of view, was undertaken. This was used to develop a taxonomy based on the different methods/functions that nature successfully uses to attach dissimilar tissues. One of the key methods that nature uses to join dissimilar materials is a transitional zone of stiffness at the insertion site. This method was used to propose bio-inspired solutions with a transitional zone of stiffness at the joint site for several glass fibre reinforced plastic (GFRP) to steel adhesively bonded joint configurations. The transition zone was used to reduce the material stiffness mismatch of the joint parts. A numerical finite element model was used to identify the optimum variation in material stiffness that minimises potential failure of the joint. The best bio-inspired joints showed a 118% increase of joint strength compared to the standard joints.

  16. Investigation of a piezoelectric valveless micropump with an integrated stainless-steel diffuser/nozzle bulge-piece design

    NASA Astrophysics Data System (ADS)

    Tseng, Li-Yu; Yang, An-Shik; Lee, Chun-Ying; Cheng, Chiang-Ho

    2013-08-01

    To meet a growing need in biological and medical applications, innovative micro-electro-mechanical system (MEMS) technologies have realized important progress on the micropump as one of the essential fluid handling devices to deliver and control precise amounts of fluid flowing along a specific direction. This research proposes a piezoelectric (PZT) valveless micropump adopting an integrated diffuser/nozzle bulge-piece design. The pump mainly consisted of a stainless-steel structured chamber with dimensions of 8 mm in diameter and 70 μm in depth to enhance its long-term reliability, low-cost production, and maximized liquid compatibility. A PZT diaphragm was also used as a driving source to propel the liquid stream under actuation. As commonly used indices to describe pump operation, the delivered volumetric flow rates and pressures were determined at bulge-piece diameters of 2, 4 and 6 mm, with a driving voltage of 160 Vpp and frequency ranging from 50 to 550 Hz. Measurements and simulations have successfully shown that this micropump is capable of operating at a greater volumetric flow rate of up to 1.2 ml min-1 with a maximum back pressure of 5.3 kPa. In addition, the time-recurring flow behavior in the chamber and its relationship to the pumping performance were examined in detail.

  17. An investigation into the applicability of Barkhausen noise technique in evaluation of machining properties of high carbon steel parts with different degrees of spheroidization

    NASA Astrophysics Data System (ADS)

    Jarrahi, Faezeh; Kashefi, Mehrdad; Ahmadzade-Beiraki, Esmaeel

    2015-07-01

    Capability of Barkhausen noise (BN) technique in evaluation of spheroidizing process and determination of the consequent machining properties were investigated. Samples with different degrees of spheroidization were produced from AISI 1060 steel. The microstructure was characterized using SEM metallographic image analysis. Machining properties were evaluated in terms of machining force and surface roughness. The machining properties showed a decrease followed by an increase with increasing spheroidization degree. BN parameters of RMS and peak height values exhibited an increase followed by a decline with increasing spheroidization. Good resolution of peak height parameter in determination of spheroidizing degree provided to define a controlling range (peak height values bigger than 3800 mV) in which the optimum machining properties are achieved.

  18. An Investigation of the Massive Transformation from Ferrite to Austenite in Laser-Welded Mo-Bearing Stainless Steels

    NASA Astrophysics Data System (ADS)

    Perricone, M. J.; Dupont, J. N.; Anderson, T. D.; Robino, C. V.; Michael, J. R.

    2011-03-01

    A series of 31 Mo-bearing stainless steel compositions with Mo contents ranging from 0 to 10 wt pct and exhibiting primary δ-ferrite solidification were analyzed over a range of laser welding conditions to evaluate the effect of composition and cooling rate on the solid-state transformation to γ-austenite. Alloys exhibiting this microstructural development sequence are of particular interest to the welding community because of their reduced susceptibility to solidification cracking and the potential reduction of microsegregation (which can affect corrosion resistance), all while harnessing the high toughness of γ-austenite. Alloys were created using the arc button melting process, and laser welds were prepared on each alloy at constant power and travel speeds ranging from 4.2 to 42 mm/s. The cooling rates of these processes were estimated to range from 10 K (°C)/s for arc buttons to 105 K (°C)/s for the fastest laser welds. No shift in solidification mode from primary δ-ferrite to primary γ-austenite was observed in the range of compositions or welding conditions studied. Metastable microstructural features were observed in many laser weld fusion zones, as well as a massive transformation from δ-ferrite to γ-austenite. Evidence of epitaxial massive growth without nucleation was also found when intercellular γ-austenite was already present from a solidification reaction. The resulting single-phase γ-austenite in both cases exhibited a homogenous distribution of Mo, Cr, Ni, and Fe at nominal levels.

  19. INVESTIGATION OF THE POTENTIAL FOR CAUSTIC STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS

    SciTech Connect

    Lam, P.

    2009-10-15

    The evaporator recycle streams contain waste in a chemistry and temperature regime that may be outside of the current waste tank corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history (1998-2008) of Tanks 30 and 32 showed that these tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved F-Area tanks. Therefore, for the Type III/IIIA waste tanks the efficacy of the stress relief of welding residual stress is the only corrosion-limiting mechanism. The objective of this experimental program is to test carbon steel small scale welded U-bend specimens and large welded plates (12 x 12 x 1 in.) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in Tanks 30 and 32. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test is currently in progress, but no cracking has been observed after 9 weeks of immersion. Based on the preliminary results, it appears that the environmental conditions of the tests are unable to develop stress corrosion cracking within the duration of these tests.

  20. An investigation of fracture toughness, fatigue-crack growth, sustained-load flaw growth, and impact properties of three pressure vessel steels

    NASA Technical Reports Server (NTRS)

    Hudson, C. M.; Newman, J. C., Jr.; Lewis, P. E.

    1975-01-01

    The elastic fracture toughness of the three steels is shown to not decrease significantly with decreasing temperature from room temperature to about 244 K (-20 F.). The elastic fracture toughness of the three steels increased with increasing specimen width and thickness. The fatigue-crack-growth data for all three steels fall into relatively narrow scatter bands on plots of rate against stress-intensity range. An equation is shown to predict the upper bounds of the scatter bands reasonably well. Charpy impact energies decreased with decreasing temperature in the nominal temperature range from room temperature to 244 K (-20 F). The nil-ductility temperatures of the steels are discussed.

  1. Effect of carbon on irradiation-induced grain-boundary phosphorus segregation in reactor pressure vessel steels using first-principles-based rate theory model

    NASA Astrophysics Data System (ADS)

    Ebihara, Ken-ichi; Yamaguchi, Masatake; Nishiyama, Yutaka; Onizawa, Kunio; Matsuzawa, Hiroshi

    2011-07-01

    In this paper, we incorporated the effect of carbon atoms on the irradiation-induced grain-boundary phosphorus segregation into the rate theory model by considering a carbon atom as a trap site of vacancies and self-interstitial atoms, and simulated the grain-boundary phosphorus coverage in the reactor pressure vessel steels, A533B steels which were neutron-irradiated using the Halden reactor. As a result, by selecting the sink strength of vacancies and self-interstitial atoms, the simulation reproduced the experimental grain-boundary phosphorus coverage that was measured using the scanning Auger electron microprobe analysis. It was observed that the grain-boundary phosphorus coverage does not depend on the dose rate regardless of the presence of carbon atoms. Furthermore, it was confirmed that vacancies scarcely transport phosphorus atoms to grain-boundaries as compared to the transport by self-interstitial atoms and it was found that carbon atoms influence the irradiation-induced phosphorus segregation by mainly suppressing the migration of vacancies.

  2. Stainless steel

    SciTech Connect

    Lula, R.A.

    1985-01-01

    This book discusses the stainless steels for high-strength, heat-resistant or corrosion-resistant applications. It is a treatment of the properties and selection of stainless steels. Up-to-date information covers physical, mechanical and chemical properties of all stainless grades, including the new ferritic and duplex grades. The book covers physical metallurgy as well as processing and service characteristics, including service in corrosive environments. It deals with wrought and cast stainless steels and reviews fabrication from cold-forming to powder metallurgy.

  3. PM-IRRAS investigation of the interaction of serum albumin and fibrinogen with a biomedical-grade stainless steel 316LVM surface.

    PubMed

    Desroches, Marie J; Chaudhary, Nida; Omanovic, Sasha

    2007-09-01

    Polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) was applied to investigate the interaction of bovine serum albumin (BSA) and fibrinogen with a biomedical-grade 316LVM stainless steel surface, in terms of the adsorption thermodynamics and adsorption-induced secondary structure changes of the proteins. Highly negative apparent Gibbs energy of adsorption values revealed a spontaneous adsorption of both proteins onto the surface, accompanied by significant changes in their secondary structure. It was determined that, at saturated surface coverages, lateral interactions between the adsorbed BSA molecules induced rather extensive secondary structure changes. Fibrinogen's two coiled coils appeared to undergo negligible secondary structure changes upon adsorption of the protein, while large structural rearrangements of the protein's globular domains occurred upon adsorption. The secondary structure of adsorbed fibrinogen was not influenced by lateral interactions between the adsorbed fibrinogen molecules. PM-IRRAS was deemed to be viable for investigating protein adsorption and for obtaining information on adsorption-induced changes in their secondary structures.

  4. Investigation of influence of structure and TiAl3/TiAlN intermetallic coatings on the corrosion behavior of martensitic steels

    NASA Astrophysics Data System (ADS)

    Vardanyan, E.; Ramazanov, K.; Yagafarov, I.; Khamzina, A.; Agzamov, R.

    2017-05-01

    The paper considers several approaches to protect martensitic steels with ultrafine-grain (UFG) structure in aggressive environments. Scanning electron microscopy was used to study the microstructure and composition of steel substrates and coatings. The samples were also subjected to corrosion tests. Regularities of corrosion behavior were specified for the UFG steels. The samples were subjected to ion nitriding in a glow discharge and deposition of protective TiAl3/TiAlN coatings in vacuum arc discharge plasma. Corrosion rates were identified for different treatments.

  5. Replacement steel windows

    SciTech Connect

    Brown, M.A.; Condren, S.J.

    1999-07-01

    This paper presents the authors experiences in the investigation, design, and installation of replacement steel windows for two renovation projects at a major university in the northeast: a student residential complex and the law school. The authors review the construction of the existing walls (cast-in-place concrete barrier wall at the student residential complex and brick and stone masonry barrier wall at the law school), and the construction and performance of the original steel windows. To maintain the appearance of these architecturally significant buildings, the university elected to install replacement steel windows. The authors discuss special design consideration for steel windows (versus the more prevalent aluminum replacement window), including available window section profiles, corrosion protection, frame fabrication, and glazing design. The authors also review window flashing concepts they employed for the barrier wall construction, which has no drainage cavity. The authors summarize lessons learned during the window selection, design, fabrication, testing, and installation phases of the projects, and present recommendations for improved durability and water penetration resistance of steel windows.

  6. Investigation on Mechanical Properties of Boron Steel for Variation of Quenching Temperature and its Hot Press Forming Simulation

    NASA Astrophysics Data System (ADS)

    Li, Yang; An, Sang-Hyun; Kang, Chung-Gil

    2010-06-01

    Hot Forming Die Quenching (HFDQ) process is a forming method which provides various advantages such as excellent mechanical properties and formability, good weldability, and little springback of the deformed materials. HFDQ technology can solve the inconsistency between crashworthiness and fuel economy for its high intensity and good formability at high temperature. While partial quenching can provide long elongation and high intensity on one product at different positions. In this paper, the investigation about the mechanical properties was carried on the Al-Si coated boron sheet after heating which can be considered as a data base of partial quenching. In addition, a relevant simulation model was built to provide theoretic basis for the practical manufacturing process. The data from this paper can be applied into the manufacturing process of B-pillar in automobile.

  7. Utilization of the equipment and program cine- and telerecording complex for the high-frequency steel pipe welding investigation

    NASA Astrophysics Data System (ADS)

    Konovalov, Nikolai A.; Veselovsky, Vladimir B.; Furmanov, Valeri B.; Kovalenko, Vladimir I.; Lakhno, Nikolay I.; Kovika, Nikolai D.; Novikov, Leonid V.; Scherbina, Vadim N.; Zlydennaya, Lyubov M.

    1995-08-01

    With the aim of technological process automatization and control for high-frequency welding of different diameter pipes, the machine-program complex (APC) was designed. APC gives the opportunity to create the cine- and telerecording of process in production conditions at the mill '159-529' of the Novomoskovsky Tube Rolling Mill, Ukraine). With the help of APC in real functioning mill conditions, the character of flashing zone length changing and the angle of convergence depending on pipe welding speed was investigated. Also the zone of jumpers is defined. The comparison of theoretical and experimental data gave an opportunity to define a welding rate which is optimal for the most qualitative values of welded joints in the range of pipe products of mill '159-529'.

  8. Investigation of the Corrosion Behavior of Poly(Aniline-co-o-Anisidine)/ZnO Nanocomposite Coating on Low-Carbon Steel

    NASA Astrophysics Data System (ADS)

    Mobin, M.; Alam, R.; Aslam, J.

    2016-07-01

    A copolymer of aniline (AN) and o-anisidine (OA), Poly(AN-co-OA) and its nanocomposite with ZnO nanoparticles, Poly(AN-co-OA)/ZnO were synthesized by chemical oxidative polymerization using ammonium persulfate as an oxidant in hydrochloric acid medium. The synthesized compounds were characterized using FTIR, XRD, SEM-EDS, TEM, and electrical conductivity techniques. The copolymer and nanocomposite were separately dissolved in N-methyl-2-pyrrolidone and were casted on low-carbon steel specimens using 10% epoxy resin as a binder. The anticorrosive properties of the coatings were studied in different corrosive environments such as 0.1 M HCl, 5% NaCl solution, and distilled water at a temperature of 30 °C by conducting corrosion tests which include immersion test, open circuit potential measurements, potentiodynamic polarization measurements, and atmospheric exposure test. The surface morphology of the coatings prior to and after one-month immersion in corrosive solution was evaluated using SEM. It was observed that the nanocomposite coating exhibited higher corrosion resistance and provided better barrier properties in comparison with copolymer coating. The presence of ZnO nanoparticles improved the anticorrosion properties of copolymer coating in all corrosive media subjected to investigation.

  9. An Investigation of the Mold-Flux Performance for the Casting of Cr12MoV Steel Using a Mold Simulator Technique

    NASA Astrophysics Data System (ADS)

    Zhou, Lejun; Wang, Wanlin; Xu, Chao; Zhang, Chen

    2017-08-01

    Mold flux plays important roles in the process of continuous casting. In this article, the performance of mold flux for the casting of Cr12MoV steel was investigated by using a mold simulator. The results showed that the slag film formed in the gap between the initial shell and mold hot surface is thin and discontinuous during the casting process with the Flux BM, due to the absorption of chromic oxide inclusions into the liquid slag, while the slag film formed in the case of the optimized Flux NEW casting process is uniform. The main precipitated crystals in Flux BM slag film are cuspidine (Ca4Si2O7F2) and Cr3O4, but only Ca4Si2O7F2 precipitated in the Flux NEW case. Besides, both the responding temperature and heat flux in the case of Flux BM are relatively higher and fluctuate in a larger amplitude. The surface of the shell obtained in the case of the Flux BM experiment is quite uneven, and many severe depressions, cracks, and entrapped slags are observed in the surface due to the lack of lubrication. However, the obtained shell surface in the case of the Flux NEW shows good surface quality due to the addition of B2O3 and the adjustment of basicity, which can compensate for the negative effects of the mold-flux properties caused by the absorption of chromic oxide during the casting process.

  10. Tribological investigation of novel HDPE-HAp-Al2O3 hybrid biocomposites against steel under dry and simulated body fluid condition.

    PubMed

    Nath, Shekhar; Bodhak, Subhadip; Basu, Bikramjit

    2007-10-01

    Among various biocompatible polymers, polyethylene based materials have received wider attention because of its excellent stability in body fluid, inertness, and easy formability. Attempts have been made to improve their physical properties (modulus/strength) to enable them to be used as load bearing hard tissue replacement applications. Among such attempts, high density polyethylene (HDPE)-hydroxyapatite (HAp) composite (HAPEX), has already been developed for total hip replacement (THR) acetabular cup and low load bearing bone tissue replacement. In the present work, alumina has been added as a partial replacement of HAp phase to improve the mechanical and tribological properties of the HAPEX composite. In an attempt to assess the suitability of the developed composite in THR application, the tribological properties against steel counterbody under both in air and simulated body fluid (SBF), have been investigated and efforts have been made to understand the wear mechanisms. The fretting wear study indicates the possibility of achieving extremely low COF (Coefficient of Friction approximately 0.09) as well as higher wear resistance (order of 10(-6) mm(3)/N m) with the newly developed composites in SBF. A low wear depth of approximately 4.6-5.3 microm is recorded, irrespective of fretting environment. The implication of the work is that optimal and combined addition of bioactive and bioinert ceramic filler to HDPE can provide a good opportunity to obtain hybrid biocomposites with better combination of physical properties (modulus, hardness) as well as low friction and high wear resistance.

  11. Microstructural investigation, using small-angle neutron scattering (SANS), of Optifer steel after low dose neutron irradiation and subsequent high temperature tempering

    NASA Astrophysics Data System (ADS)

    Coppola, R.; Lindau, R.; Magnani, M.; May, R. P.; Möslang, A.; Valli, M.

    2007-08-01

    The microstructural effect of low dose neutron irradiation and subsequent high temperature tempering in the reduced activation ferritic/martensitic steel Optifer (9.3 Cr, 0.1 C, 0.50 Mn, 0.26 V, 0.96 W, 0.66 Ta, Fe bal wt%) has been studied using small-angle neutron scattering (SANS). The investigated Optifer samples had been neutron irradiated, at 250 °C, to dose levels of 0.8 dpa and 2.4 dpa. Some of them underwent 2 h tempering at 770 °C after the irradiation. The SANS measurements were carried out at the D22 instrument of the High Flux Reactor at the Institut Max von Laue - Paul Langevin, Grenoble, France. The differences observed in nuclear and magnetic SANS cross-sections after subtraction of the reference sample from the irradiated one suggest that the irradiation and the subsequent post-irradiation tempering produce the growth of non-magnetic defects, tentatively identified as microvoids.

  12. Investigation on the Fluid Flow and Mixing Phenomena in a Ruhrstahl-Heraeus (RH) Steel Degasser Using Physical Modeling

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Li, Fei

    2014-07-01

    In this article, the water model was established to investigate the fluid flow and mixing phenomena during the Ruhrstahl-Heraeus refining process. The mixing time was measured by detecting the conductivity. The velocity, turbulent energy and its dissipation rate were measured using a particle-image velocimetry. There were several findings in the current study. The jet from the downleg penetrated to the bottom of the ladle, collided with the right wall of the ladle, and then went upward and sloped left to enter the upleg, generating a recirculation eddy below the upleg. The turbulent fluctuation velocities at different directions were different so that the k- ɛ turbulent model is invalid to accurately study the fluid flow during ladle refining process. The mixing time was usually three to four times that of the recirculation time, and the mixing was different at different locations. When the mixing time is reported, the location where the mixing time is measured should be clearly mentioned. The mixing time was dependent on the stirring power by t mix ~ ɛ-0.42.

  13. Investigation of thin layers deposited by two PVD techniques on high speed steel produced by powder metallurgy

    NASA Astrophysics Data System (ADS)

    Jakubéczyová, D.; Hvizdoš, P.; Selecká, M.

    2012-04-01

    This study was intended to investigate the properties and cutting performance with thin layers applied by two PVD techniques. PVD techniques ARC and LARC were used for the deposition of thin coatings onto cutting tools prepared by powder metallurgy. Advanced types of layers - monolayer AlTiCrN and nanocomposite type of nc-AlTiN/Si3N4 layer - were analyzed by standard techniques for surface status and quality assessment - roughness, hardness, layer thickness, chemical composition by GDOES, tribological properties at room and elevated temperature. Durability testing of the cutting tools was carried out according to the standard ISO 3685-1999. The nanocomposite nc-AlTiN/Si3N4 layer achieved lower roughness when compared to monolayer AlTiCrN which leads to the achievement of higher hardness and better layer quality. The HV0.5 hardness values were ∼26 GPa. The results showed a 2-3-times longer durability of the cutting tools in comparison with equivalent uncoated PM and traditional materials. The deposited coatings contributed to the improvement of their durability.

  14. Dendritic inhomogeneity of stainless maraging steels

    SciTech Connect

    Krasnikova, S.I.; Drobot, A.V.; Shmelev, A.Y.; Vukelich, S.B.

    1986-03-01

    The authors investigated dendritic inhomogeneity in industrial ingots 630 mm (steel I) in diameter and 500 mm (steel II) in diameter. The variation in the degree of dendritic inhomogeneity was investigated over the height of the ingots and across the sections on an MS-46 microprobe. It was established that the elements can be placed in the following order in accordance with the degree of reduction in the liquation factor: titanium, molybdenum, nickel, chromium, and cobalt. Titanium and molybdenum exhibit forward liquation in both steels, and chromium in steel II. The distribution of nickel and chromium in the steel I ingots and cobalt in the steel II ingots is unconventional. Dendritic inhomogeneity, which must be considered in assigning the heat treatment for finished articles, develops during the crystallization of stainless maraging steels.

  15. A progress report on the use of electrochemical noise to investigate the effects of zebra mussel attachment on the corrosion resistance of AISI Type 304 stainless steel and carbon steel in lake water

    SciTech Connect

    Brennenstuhl, A.M.; Sim, B.; Claudi, R.

    1996-12-31

    The electrochemical noise technique was used to determine the effect of zebra mussel settlement on the corrosion performance of AISI Type 304 stainless steel and carbon steel (ASTM A53 Grade B). These materials represent alloys commonly used for handling untreated Great Lakes water at Ontario Hydro`s power generating plants. This work was motivated by a concern that zebra mussel settlement will lead to accelerated attack of these materials as a result of the establishment of stable crevice conditions and the growth of corrosion influencing anaerobic sulfate-reducing bacteria (SRB). Corrosion monitoring was carried out in a field test facility that uses the same untreated Lake Erie water as Ontario Hydro`s Nanticoke Thermal Generating Station. The test program extended from May through December 1993. During this period, a number of electrochemical parameters were monitored simultaneously, including coupling current, electrochemical potential noise (EPN), electrochemical current noise (ECN), degree of localization (DoL), and resistance noise (R{sub n}). Differences were observed in the performance of the control samples and the samples to which mussels were attached. The results for the AISI Type 304 stainless steel suggested that over the period monitored, mussel attachment reduced corrosion activity. Similarly, signals from carbon steel, samples exposed to mussels, although initially displaying relatively high corrosion rates, exhibited less corrosion damage than did control samples over the longer term. The reason for this difference in performance is not known but is considered to have resulted from a change in the surface environment as a result of mussel attachment, which appeared to diminish corrosion. One possible explanation may be the generation of inhibitive species by the mussels.

  16. Experimental and theoretical investigation of the inhibitory effect of new pyridazine derivatives for the corrosion of mild steel in 1 M HCl

    NASA Astrophysics Data System (ADS)

    Mashuga, Motsie E.; Olasunkanmi, Lukman O.; Ebenso, Eno E.

    2017-05-01

    The effects of four pyridazine derivatives namely, 2-(6-chloropyridazin-3-yl)-2-phenylacetonitrile (P1), 3-(6-chloro-3-pyridazinyl)-1H-indole (P2), 4-(6-chloropyridazin-3-yl)benzoic acid (P3) and 3-(6-chloropyridazin-3-yl)benzoic acid (P4) on electrochemical dissolution of mild steel in 1 M HCl were studied using electrochemical, spectroscopic, and theoretical computational chemistry techniques. The inhibition efficiency increases with increasing concentration of the inhibitors and the shift in corrosion potentials obtained revealed that the compounds are mixed-type inhibitors and steel dissolution was found to be a charge transfer process with the steel/electrolyte interface showed pseudo-capacitive behaviour. P1 and P2 showed the best protection performances for mild steel in the studied medium, attributable to the presence of more nitrogen atoms and unsaturated groups in their molecules compared to P3 and P4. The experimental adsorption data obeyed the Langmuir and Temkin isotherm models and was found to involve both physisorption and chemisorption. Spectroscopic studies revealed that the inhibitor molecules interact chemically with mild steel and the pyridazine ring is actively involved in these interactions. Quantum chemical calculations also showed that pyridazine ring has the tendency of interacting with metallic atoms via both forward and backward donations. Molecular dynamic simulation revealed that the molecules can adsorb strongly onto the surface of iron in a near flat orientation.

  17. Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation.

    PubMed

    Kim, Y G; Song, J B; Choi, Y H; Yang, D G; Kim, S G; Lee, H G

    2016-11-01

    This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated. The results of the quench test at a heater current (Ih) of 12, 13, and 14 A indicate that the MI coil possesses a self-protecting characteristic resulting from the "current bypass" through the turn-to-turn contact. However, the test coil was not self-protecting at Ih = 15 A because the Joule heat energy generated by the radial current flow was not completely dissipated due to the characteristic resistance of the metallic insulation tape and the non-superconducting materials, including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS) tape. Even though the MI coil possesses superior thermal and electrical stability relative to those of conventional HTS coils co-wound with an organic material as turn-to-turn insulation, it is essential to consider the critical role of the Joule heat energy resulting from the operating current and stored magnetic energy as well as the characteristic resistances in order to further develop self-protective 2G HTS magnets.

  18. Investigation on quench initiation and propagation characteristics of GdBCO coil co-wound with a stainless steel tape as turn-to-turn metallic insulation

    NASA Astrophysics Data System (ADS)

    Kim, Y. G.; Song, J. B.; Choi, Y. H.; Yang, D. G.; Kim, S. G.; Lee, H. G.

    2016-11-01

    This paper investigates the quench initiation and propagation characteristics of a metallic insulation (MI) coil by conducting thermal quench tests for a GdBCO single-pancake coil co-wound with a stainless steel tape as the turn-to-turn MI. The test results confirmed that the MI coil exhibited superior thermal and electrical stabilities compared to the conventional coils co-wound with organic insulation material because the operating current could flow along the radial direction due to the existence of a turn-to-turn contact when a local hot spot was generated. The results of the quench test at a heater current (Ih) of 12, 13, and 14 A indicate that the MI coil possesses a self-protecting characteristic resulting from the "current bypass" through the turn-to-turn contact. However, the test coil was not self-protecting at Ih = 15 A because the Joule heat energy generated by the radial current flow was not completely dissipated due to the characteristic resistance of the metallic insulation tape and the non-superconducting materials, including the substrate, stabilizer, and buffer layers within the high-temperature superconductor (HTS) tape. Even though the MI coil possesses superior thermal and electrical stability relative to those of conventional HTS coils co-wound with an organic material as turn-to-turn insulation, it is essential to consider the critical role of the Joule heat energy resulting from the operating current and stored magnetic energy as well as the characteristic resistances in order to further develop self-protective 2G HTS magnets.

  19. Atom probe tomography and nano secondary ion mass spectroscopy investigation of the segregation of boron at austenite grain boundaries in 0.5 wt.% carbon steels

    NASA Astrophysics Data System (ADS)

    Seol, J. B.; Lim, N. S.; Lee, B. H.; Renaud, L.; Park, C. G.

    2011-06-01

    The grain boundary segregation of boron atoms in high strength low alloy steels containing 50 ppm boron was accomplished using atom probe tomography (APT) and nano-beam secondary ion mass spectroscopy (SIMS). The formation of boro-carbides under an excessive addition of boron to the steels was identified through the SIMS and TEM. The APT was performed in order to evaluate the composition of the alloying elements, such as, boron and carbon, segregated at prior austenite grain boundaries. The boron contents at the prior austenite grain boundaries were approximately 1.7 ± 0.2 at.%, which was approximately 70 times more than the amount of boron added to the steels.

  20. Experimental Investigation of Mechanical Properties of Welded Corten Steel A588 Grade Plate Using ER70S - 6 Filler Material for Construction Application

    NASA Astrophysics Data System (ADS)

    Deepak, J. R.; Bupesh Raja, V. K.; Janardhan Guptha, Mittapalli; Durga Prasad, Palaparthi Hari; Sriram, V.

    2017-05-01

    ASTM A588 Grade A steel plate is a high strength, low alloy structural steel with 0.19 % of carbon content. When exposed to the atmosphere, A588 Grade A is suitable for construction in the bare (paint - free) condition. The main problems are lack of fusion, lack of penetration and corrosion on heat affected zone. In this research work Corten ASTM A588 Grade steel of 3mm thickness is electroplated with copper and then both raw and copper electroplated are welded by GMAW welding process with ER70S-6 as a filler material. The welded ASTM A588 is cut according to ASTM size for further testing of mechanical properties. Considering its welding strength after the process of electroplating, this research clearly states the metal can be utilized for better results in any given field. Here both the tensile and hardness are higher in copper electroplated welded when compare to raw welded.

  1. Post-irradiation annealing behavior of microstructure and hardening of a reactor pressure vessel steel studied by positron annihilation and atom probe tomography

    NASA Astrophysics Data System (ADS)

    Kuramoto, A.; Toyama, T.; Takeuchi, T.; Nagai, Y.; Hasegawa, M.; Yoshiie, T.; Nishiyama, Y.

    2012-06-01

    Post-irradiation annealing (PIA) behavior of irradiation-induced microstructural changes and hardening of an A533B (0.16 wt.% Cu) steel after neutron-irradiation of 3.9 × 1019 n cm-2 (0.061 displacement per atom (dpa)) at 290 °C was studied by positron annihilation spectroscopy (PAS), atom probe tomography (APT) and Vickers microhardness measurements. Coincidence Doppler broadening and positron lifetime measurements clearly reveal two recovery stages; (i) as-irradiated state to annealing at 450 °C and (ii) annealing from 450 to 600 °C. The first stage is due to annealing out of the most of irradiation-induced vacancy-related defects, while the second stage corresponds to dissolving of irradiation-induced solute nanoclusters (SCs). APT observations reveal that the SCs are enriched with Cu, Mn, Ni and Si and that their number densities decrease with increasing annealing temperature without coarsening to give almost complete recovery at 550 °C. The experimental hardening is almost twice the SC hardening estimated by the Russell-Brown model below 350 °C, whereas it is almost the same as that estimated in the range 400-550 °C.

  2. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    SciTech Connect

    Malik, Hitendra K.; Singh, Omveer; Dahiya, Raj P.

    2015-08-28

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N{sub 2} and 30% H{sub 2} gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples.

  3. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    NASA Astrophysics Data System (ADS)

    Malik, Hitendra K.; Singh, Omveer; Dahiya, Raj P.

    2015-08-01

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N2 and 30% H2 gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples.

  4. 75 FR 81309 - Stainless Steel Plate from Belgium, Italy, Korea, South Africa, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... COMMISSION [Investigation Nos. 701-TA-376 and 379 and 731-TA-788, 790-793 (Second Review)] Stainless Steel... stainless steel plate from Belgium and South Africa and the antidumping duty orders on stainless steel plate... steel plate from Belgium and South Africa and/or the antidumping duty orders on stainless steel...

  5. STEFINS: a steel freezing integral simulation program

    SciTech Connect

    Frank, M.V.

    1980-09-01

    STEFINS (STEel Freezing INtegral Simulation) is a computer program for the calculation of the rate of solidification of molten steel on solid steel. Such computations arize when investigating core melt accidents in fast reactors. In principle this problem involves a coupled two-dimensional thermal and hydraulic approach. However, by physically reasonable assumptions a decoupled approach has been developed. The transient solidification of molten steel on a cold wall is solved in the direction normal to the molten steel flow and independent from the solution for the molten steel temperature and Nusselt number along the direction of flow. The solutions to the applicable energy equations have been programmed in cylindrical and slab geometries. Internal gamma heating of steel is included.

  6. Steel Rattler

    NASA Astrophysics Data System (ADS)

    Trudo, Robert A.; Stotts, Larry G.

    1997-07-01

    Steel Rattler is a multi-phased project to determine the feasibility of using commercial off-the-shelf components in an advanced acoustic/seismic unattended ground sensor. This project is supported by the Defense Intelligence Agency through Sandia National Laboratories as the lead development agency. Steel Rattler uses advanced acoustic and seismic detection algorithms to categorize and identify various heavy vehicles down to the number of cylinders in the engine. This detection is accomplished with the capabilities of new, high-speed digital signal processors which analyze both acoustic and seismic data. The resulting analysis is compared against an onboard library of known vehicles and a statistical match is determined. An integrated thermal imager is also employed to capture digital thermal images for subsequent compression and transmission. Information acquired by Steel Rattler in the field is transmitted in small packets by a built-in low-power satellite communication system. The ground station receivers distribute the coded information to multiple analysis sites where the information is reassembled into coherent messages and images.

  7. Novel experimental methods for investigating high speed friction of titanium-aluminum-vanadium/tool steel interface and dynamic failure of extrinsically toughened DRA composites

    NASA Astrophysics Data System (ADS)

    Irfan, Mohammad Abdulaziz

    Dynamic deformation, flow, and failure are integral parts of all dynamic processes in materials. Invariably, dynamic failure also involves the relative sliding of one component of the material over the other. Advances in elucidation of these failure mechanisms under high loading rates has been of great interest to scientists working in this area. The need to develop new dynamic mechanical property tests for materials under well characterized and controllable loading conditions has always been a challenge to experimentalists. The current study focuses on the development of two experimental methods to study some aspects of dynamic material response. The first part focuses on the development of a single stage gas gun facility for investigating high-speed metal to metal interfacial friction with applications to high speed machining. During the course of this investigation a gas gun was designed and built capable of accelerating projectiles upto velocities of 1 km/s. Using this gas gun pressure-shear plate impact friction experiments were conducted to simulate conditions similar to high speed machining at the tool-workpiece interface. The impacting plates were fabricated from materials representing the tribo-pair of interest. Accurate measurements of the interfacial tractions, i.e. the normal pressure and the frictional stress at the tribo-pair interface, and the interfacial slip velocity could be made by employing laser interferometry. Normal pressures of the order of 1-2 MPa were generated and slipping velocities of the order of 50 m/s were obtained. In order to illustrate the structure of the constitutive law governing friction, the study included experimental investigation of frictional response to step changes in normal pressure and interfacial shear stress. The results of these experiments indicate that sliding resistance for Ti6Al4V/CH steel interface is much lower than measured under quasi-static sliding conditions. Also the temperature at the interface strongly

  8. Investigation of charcoal cloth as a sorbent for integrated sampling of solvent vapors in mixed-expired breath using a new stainless steel sampler.

    PubMed

    Glaser, R A; Arnold, J E

    1989-02-01

    A stainless steel device for integrated sampling of solvents present in mixed-expired breath is described. During sampling, the subject inhales breathing air through commercial charcoal inhalation canisters. Exhaled breath is sampled from the mainstream using 45-mm wafers of charcoal cloth or from the sidestream on other sorbents. The device concentrates trace contaminants present in large volumes of breath. The charcoal cloth sorbent was evaluated for sampling and analysis of m-xylene and 1,1,1-trichloroethane under simulated physiological conditions. These samples were collected from atmospheres of either analyte generated at 35 degrees-40 degrees C and 80%-90% relative humidity to simulate an exhaled breath sample matrix. Concentrations sampled ranged from 2.2 to 190 mg/m3 for 1,1,1-trichloroethane and from 0.44 to 35.6 mg/m3 for m-xylene. Volumes sampled ranged from 10 to 50 L. The m-xylene samples were collected using a 3-wafer front and a 2-wafer backup bed of charcoal cloth; 1,1,1-trichloroethane samples were collected using a 10-wafer front and a 1-wafer backup bed. All samples were desorbed in carbon disulfide and analyzed via gas chromatography using a flame ionization detector. The volume of desorption solvent ranged from 1.7 to 2.5 mL per wafer of cloth. The quantitation limit is estimated to be 2.0 micrograms/L for 1,1,1-trichloroethane and 0.4 micrograms/L m-xylene for a 50-L sample. At least 80% recovery was obtained for m-xylene or 1,1,1-trichloroethane samples stored from 1 to 14 days after collection, if the samples were refrigerated at 0 degrees C after an initial 7-day storage period at room temperature. The recovery of hexane, 1-hexene, ethyl acetate, isopropanol, methylene chloride, and methyl isobutyl ketone from the charcoal cloth also has been investigated and is reported. With the exception of isopropanol, all analytes were recovered quantitatively from the charcoal cloth by desorption with carbon disulfide following storage for 1 to 17

  9. Combination of Different In Situ Characterization Techniques and Scanning Electron Microscopy Investigations for a Comprehensive Description of the Tensile Deformation Behavior of a CrMnNi TRIP/TWIP Steel

    NASA Astrophysics Data System (ADS)

    Weidner, Anja; Biermann, Horst

    2015-08-01

    The class of low-carbon, high-alloy CrMnNi steels exhibits outstanding mechanical properties with respect to high strength and ductility due to either transformation-induced plasticity (TRIP) or twinning-induced plasticity (TWIP) effect depending on chemical composition and deformation temperature. However, the ongoing deformation mechanisms like the formation of stacking faults, martensitic phase transformation or deformation-induced twinning are overlapping and the kinetics of the microstructure evolution are quite complex. Therefore, in addition to macroscopic deformation tests and microstructural investigations by scanning electron microscopy, a combination of several in situ characterization techniques with either high lateral and/or temporal resolution as well as providing integral volume information were chosen in order to give a thoroughly and comprehensive description of the deformation behavior of CrMnNi TRIP/TWIP steels. In addition, the complementary in situ techniques like in situ nanoindentation, micro-digital image correlation, and acoustic emission measurements provide excellent possibility for description of materials behavior on a multiscale level from the submicrometer scale up to the macroscopic range. The results obtained by the complementary techniques can support the future modeling of the deformation behavior of TRIP/TWIP steels dependent on chemical composition, temperature, grain size and grain orientation.

  10. An investigation of microbial diversity in crude oil & seawater injection systems and microbiologically influenced corrosion (MIC) of linepipe steels under different exposure conditions

    NASA Astrophysics Data System (ADS)

    AlAbbas, Faisal Mohammed

    During oil and gas operations, pipeline networks are subjected to different corrosion deterioration mechanisms that result from the interaction between the fluid process and the linepipe steel. Among these mechanisms is microbiologically influenced corrosion (MIC) that results from accelerated deterioration caused by different indigenous microorganisms that naturally reside in the hydrocarbon and associated seawater injection systems. The focus of this research is to obtain comprehensive understanding of MIC. This work has explored the most essential elements (identifications, implications and mitigations) required to fully understand MIC. Advanced molecular-based techniques, including sequencing of 16S rRNA genes via 454 pyrosequencing methodologies, were deployed to provide in-depth understanding of the microbial diversity associated with crude oil and seawater injection systems and their relevant impact on MIC. Key microbes including sulfate reducing bacteria (SRB) and iron reducing bacteria (IRB) were cultivated from sour oil well field samples. The microbes' phylotypes were identified in the laboratory to gain more thorough understanding of how they impact microbial corrosion. Electrochemical and advanced surface analytical techniques were used for corrosion evaluations of linepipe carbon steels (API 5L X52 and X80) under different exposure conditions. On the identification front, 454 pyrosequencing of both 16S rRNA genes indicated that the microbial communities in the corrosion products obtained from the sour oil pipeline, sweet crude pipeline and seawater pipeline were dominated by bacteria, though archaeal sequences (predominately Methanobacteriaceae and Methanomicrobiaceae) were also identified in the sweet and sour crude oil samples, respectively. The dominant bacterial phylotypes in the sour crude sample included members of the Thermoanaerobacterales, Synergistales, and Syntrophobacterales. In the sweet crude sample, the dominant phylotypes included

  11. Unveiling the Origin of Work Hardening Behavior in an Ultrafine-Grained Manganese Transformation-Induced Plasticity Steel by Hydrogen Investigation

    NASA Astrophysics Data System (ADS)

    Zhu, Xu; Li, Wei; Zhao, Hongshan; Han, Qihang; Wang, Li; Jiao, Huisheng; Jin, Xuejun

    2016-09-01

    To reveal the origin of work hardening behavior in an ultrafine-grained manganese transformation-induced plasticity (TRIP) steel, specific experiments were designed with the assistance of hydrogen. Although the effect of hydrogen on the austenite transformation was negligible, the work hardening rate ( Θ) was apparently reduced for hydrogenated samples, indicating that TRIP effect cannot account for the high Θ alone. The collaborative effect of dislocation accumulation in ferrite and austenite transformation is proposed to explain the responsible mechanism.

  12. Investigation of effect of fluoride on corrosion of 2S-0 aluminum and 347 stainless steel in fuming nitric acid at 170 F

    NASA Technical Reports Server (NTRS)

    Feiler, Charles E; Morrell, Gerald

    1954-01-01

    The effect of small additions of fluoride on the corrosion of 2S-0 aluminum and 347 stainless steel by fuming nitric acid at 170 degrees F has been evaluated quantitatively by the determination of the weight loss of metal specimens immersed in the acid. The ratio of metal surface area to volume of acid was approximately 7.5 inch (superscript)-1 in all cases. It was found that for acids containing no fluorides the weight loss of aluminum was approximately 1/5 that of stainless steel. Addition of 1 percent fluoride ion to the acid reduced the weight loss of both metals to practically zero even after 26 days of exposure to the acid at 170 degrees F. The minimum quantity of fluoride ion required to inhibit corrosion was found to be approximately 0.25 and 0.5 percent for aluminum and stainless steel, respectively, in white fuming nitric acid and 0.5 and 1 percent in red fuming nitric acid (18 percent nitrogen dioxide). These fluoride percentages were based on the total weight of acid. Provided the concentration of fluoride ion was sufficient to inhibit corrosion, the source of these ions was immaterial. Additional information concerning the effect of fluorides on corrosion was obtained by measuring the electrode potentials of the metals against a platinum reference electrode.

  13. Stainless Steel Permeability

    SciTech Connect

    Buchenauer, Dean A.; Karnesky, Richard A.

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  14. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  15. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( τ ( app)) and slip coefficient ( β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  16. Corrosion of stainless steel, 2. edition

    SciTech Connect

    Sedriks, A.J.

    1996-10-01

    The book describes corrosion characteristics in all the major and minor groups of stainless steels, namely, in austenitic, ferritic, martensitic, duplex, and precipitation hardenable steels. Several chapters are spent on those special forms of corrosion that are investigated in the great detail in stainless steels, namely, pitting corrosion, crevice corrosion, and stress corrosion cracking. The influences of thermal treatment (heat affected zone cases), composition, and microstructure on corrosion are given good coverage. Corrosive environments include high temperature oxidation, sulfidation as well as acids, alkalis, various different petroleum plant environments, and even human body fluids (stainless steels are commonly used prosthetic materials).

  17. Modified 43XX Steels for High Toughness

    DTIC Science & Technology

    1980-04-01

    AL AMMRC TR 80-20 MODIFIED 43XX STEELS FOR HIGH TOUGHNESS T CS.,•, °x ,•, o o,,o,,,sD T I W4 AftELECTE APRIL 1980 J N.J. Kar, V.F. Zackay and E.R...carried out. Isohra tasomions in these steels resulted inn bbaainni 11-v DI FOR Z 47 RITIOW OF I NOV695 IS OBSOLETE UCASFE SECURITY UCLASSIFIEDINOFTI PAGE...this investigation for Si-modified AISI 4330 steel appear to be superior to those for unmodified AISI 4340 and 300-M steels , whilst the strength-tough

  18. 76 FR 73589 - Galvanized Steel Wire From the People's Republic of China: Amended Preliminary Determination of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ... investigation covers galvanized steel wire which is a cold-drawn carbon quality steel product in coils, of solid... International Trade Administration Galvanized Steel Wire From the People's Republic of China: Amended... than fair value in the antidumping investigation of galvanized steel wire from the People's Republic...

  19. 78 FR 76815 - Steel Threaded Rod From India: Preliminary Affirmative Countervailing Duty Determination and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... International Trade Administration Steel Threaded Rod From India: Preliminary Affirmative Countervailing Duty... subsidies are being provided to producers and exporters of steel threaded rod from India. The period of... Investigation The merchandise covered by this investigation is steel threaded rod. Steel threaded rod is certain...

  20. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  1. Late Archaic-Late Woodland adaptive stability and change in the Steel Creek watershed, South Carolina: Final report of the L-Lake prehistoric investigations

    SciTech Connect

    Brooks, M.J.; Hanson, G.T.

    1989-01-01

    This report documents the research conducted in conjunction with the excavation of four prehistoric archaeological sites (38BR259, 38BR495, 38BR527 and 38BR528) on the Upper Coastal Plain of the South Atlantic Slope in South Carolina. These predominantly Woodland period sites are located on the United States Department of Energy's Savannah River Plant (SRP) in the L-Lake area of the Steel Creek watershed. The L-Lake area was surveyed during four different phases of research conducted by the South Carolina Institute of Archaeology and Anthropology. The second survey of the area was part of a 40% sample of the SRP, stratified by watersheds. This on-going, multi-year survey, completed in 1986, was implemented in order to inventory and assess the cultural resources contained in the SRP and to provide the SRP with a culture resource synthesis and management plan. The intensive survey of Steel Creek was conducted during 1981 and 1982. However, because portions of the L-Lake area were not included in the sample, no sites pertinent to this report were located. The third survey, which culminated in the present research effort, resulted from a project that began in 1980 when the Department of Energy initiated the reactivation of the L Reactor. The reactivation plan prescribed an increased discharge of thermal water. Consequently, in 1980 the Savannah River Archaeological Research Program (SRARP) was contracted to conduct an intensive archaeological survey of the Steel Creek terrace edge and bottomland as an initial step geared toward the mitigation of the effects of thermal water discharge on archaeological sites that would result from the restart of the L-Area Reactor. 204 refs.

  2. Formation of Delta Ferrite in 9 Wt Pct Cr Steel Investigated by In-Situ X-Ray Diffraction Using Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Mayr, P.; Palmer, T. A.; Elmer, J. W.; Specht, E. D.; Allen, S. M.

    2010-10-01

    In-situ X-ray diffraction (XRD) measurements using high energy synchrotron radiation were performed to monitor in real time the formation of delta ferrite in a martensitic 9 wt pct chromium steel under simulated weld thermal cycles. Volume fractions of martensite, austenite, and delta ferrite were measured as a function of temperature at a 10 K/s heating rate to 1573 K (1300 °C) and subsequent cooling. At the peak temperature, the delta ferrite concentration rose to 19 pct, of which 17 pct transformed back to austenite on subsequent cooling.

  3. An investigation of force, surface roughness and chip in surface grinding of SKD 11 tool steel using minimum quantity lubrication-MQL technique

    NASA Astrophysics Data System (ADS)

    Soepangkat, Bobby O. P.; Agustin, H. C. Kis; Subiyanto, H.

    2017-06-01

    This research aimed to analyze the viability of the minimum quantity of lubricant (MQL) technique towards normal force, tangential force, surface roughness and chip formation in surface grinding of SKD 11 tool steel. The three surface grinding parameters were varied including the type of cooling method (MQL and dry), table speed, and depth of cut. Based on statistical analysis, depth of cut is the most influential factor which affects the four responses in both dry and MQL grinding. MQL could reduce normal force and tangential force considerably, but produce higher surface roughness. In MQL grinding, the chips removal took place mostly by shearing and fracturing.

  4. The Assessment and Validation of Mini-Compact Tension Test Specimen Geometry and Progress in Establishing Technique for Fracture Toughness Master Curves for Reactor Pressure Vessel Steels

    SciTech Connect

    Sokolov, Mikhail A.; Nanstad, Randy K.

    2016-09-01

    Small specimens are playing the key role in evaluating properties of irradiated materials. The use of small specimens provides several advantages. Typically, only a small volume of material can be irradiated in a reactor at desirable conditions in terms of temperature, neutron flux, and neutron dose. A small volume of irradiated material may also allow for easier handling of specimens. Smaller specimens reduce the amount of radioactive material, minimizing personnel exposures and waste disposal. However, use of small specimens imposes a variety of challenges as well. These challenges are associated with proper accounting for size effects and transferability of small specimen data to the real structures of interest. Any fracture toughness specimen that can be made out of the broken halves of standard Charpy specimens may have exceptional utility for evaluation of reactor pressure vessels (RPVs) since it would allow one to determine and monitor directly actual fracture toughness instead of requiring indirect predictions using correlations established with impact data. The Charpy V-notch specimen is the most commonly used specimen geometry in surveillance programs. Assessment and validation of mini-CT specimen geometry has been performed on previously well characterized HSST Plate 13B, an A533B class 1 steel. It was shown that the fracture toughness transition temperature measured by these Mini-CT specimens is within the range of To values that were derived from various large fracture toughness specimens. Moreover, the scatter of the fracture toughness values measured by Mini-CT specimens perfectly follows the Weibull distribution function providing additional proof for validation of this geometry for the Master Curve evaluation of rector pressure vessel steels. Moreover, the International collaborative program has been developed to extend the assessment and validation efforts to irradiated weld metal. The program is underway and involves ORNL, CRIEPI, and EPRI.

  5. 78 FR 78382 - Steel Nails From China; Determination

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ... COMMISSION Steel Nails From China; Determination On the basis of the record \\1\\ developed in the subject five... order on steel nails from China would be likely to lead to continuation or recurrence of material injury... contained in USITC Publication 4442 (December 2013), entitled Steel Nails from China: Investigation No....

  6. 78 FR 7451 - Clad Steel Plate From Japan; Determination

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... COMMISSION Clad Steel Plate From Japan; Determination On the basis of the record \\1\\ developed in the subject... order on clad steel plate from Japan would be likely to lead to continuation or recurrence of material... contained in USITC Publication 4370 (January 2013), entitled Clad Steel Plate from Japan: Investigation No...

  7. Tension-band wiring of transverse fractures of patella. The effect of site of wire twists and orientation of stainless steel wire loop: a biomechanical investigation

    PubMed Central

    Wagner, W. W.; Kuiper, J. H.

    2006-01-01

    Tension-band wiring is commonly used to treat transverse patella fractures. The most common configuration has parallel Kirschner (K) wires and a stainless steel wire loop placed in a vertically oriented figure of eight. Early mobilisation is important but can cause detrimental displacement at the fracture site. A wooden model of a transversely fractured patella was used to compare different fixation constructs. The fracture was fixed using two K wires and a stainless steel wire loop. One or two wire twists were used, placed either arbitrarily or at corners of the loop. The loop was oriented either vertically or horizontally. Interfragmentary compression at the point of wire breakage and permanent displacement on cyclic loading was measured for each construct. Placement of the figure of eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% (p<0.05, Tukey post hoc test). On cyclic loading, all constructs with vertical figure of eight but none with a horizontal construct failed (p=0.01; Fisher’s exact test). Permanent fracture displacement after cyclic loading was 67% lower with horizontal figure of eight constructs (p<0.05; t test). Placing wire twists at the corner and a horizontal placement of figure of eight improves stability of the construct. PMID:17033766

  8. An investigation of the typical corrosion parameters used to test polymer electrolyte fuel cell bipolar plate coatings, with titanium nitride coated stainless steel as a case study

    NASA Astrophysics Data System (ADS)

    Orsi, A.; Kongstein, O. E.; Hamilton, P. J.; Oedegaard, A.; Svenum, I. H.; Cooke, K.

    2015-07-01

    Stainless steel bipolar plates (BPP) for polymer electrolyte membrane fuel cells (PEMFCs) have good manufacturability, durability and low costs, but inadequate corrosion resistance and elevated interfacial contact resistance (ICR) in the fuel cell environment. Thin film coatings of titanium nitride (TiN) of 1 μm in thickness, were deposited by means of physical vapour deposition (PVD) process on to stainless steel (SS) 316L substrates and were evaluated, in a series of tests, for their level of corrosion protection and ICR. In the ex-situ corrosion tests, variables such as applied potential, experimental duration and pH of the sulphate electrolyte at 80 °C were altered. The ICR values were found to increase after exposure to greater applied potentials and electrolytes of a higher pH. In terms of experimental duration, the ICR increased most rapidly at the beginning of each experiment. It was also found that the oxidation of TiN was accelerated after exposure to electrolytes of a higher pH. When coated BPPs were incorporated into an accelerated fuel cell test, the degradation of the fuel cell cathode resembled the plates that were tested at the highest anodic potential (1.4 VSHE).

  9. Experimental investigations on the state of the friction-welded joint zone in steel hybrid components after process-relevant thermo-mechanical loadings

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Bouguecha, A.; Vucetic, M.; Peshekhodov, I.; Matthias, T.; Kolbasnikov, N.; Sokolov, S.; Ganin, S.

    2016-10-01

    As a part of the newly established Collaborative Research Center 1153 (SFB 1153) "Process chain for the manufacturing of hybrid high-performance components by tailored forming" at the Leibniz Universität Hannover, the Institute of Forming Technology and Machines (IFUM) examines the influence of thermo-mechanical stresses on the reduced Young's modulus as well as the hardness of hybrid (steel-steel compound) joined semi-finished products. Currently the expertise in the production of bulk metal formed parts is limited to mono-materials. For manufacturing parts of hybrid materials and also for the methods of the new process routes, practical experience has to be gained. The subproject C1 within the collaborative research center 1153 with the short title "Failure Prediction" deals with the question, if the hybrid semi-finished products fulfill the thermo-mechanical demands or if they fail at the joining zone (JZ) during forging. For this purpose, stresses similar to those in the process were imposed on hybrid semi-finished products by torsion tests by using the thermo-mechanical test system Gleeble 3800. Afterwards, the specimens were examined metallographically and by nanoindentations with the help of a TriboIndenter TI950. Thus, first knowledge on the behaviour of thermo-mechanical stresses on the reduced Young's modulus and the hardness of hybrid joined semi-finished parts was gained.

  10. Investigation of the development of irradiation-induced precipitates in VVER-440 type reactor pressure vessel steels and weld metals after irradiation and annealing

    SciTech Connect

    Grosse, M.; Nitzsche, P.; Boehmert, J.; Brauer, G.

    1999-10-01

    The development of irradiation-induced precipitates in VVER-440 type reactor pressure vessel steels 15Kh2MFA and weld metals SV-10KhMFT during irradiation and post-irradiation annealing is studied by small angle neutron and X-ray scattering. The kinetic conditions for the precipitation of particles, which already exist in the unirradiated state, seem to be improved at temperatures of about 270 C due to the irradiation. The size distribution of the irradiation-induced precipitates depends on the copper content and differs between weld and base metal. A strong correlation between the formation of irradiation-induced precipitates and the irradiation hardening is found. The hardness nearly linearly depends on the number of these precipitates.

  11. Investigation of high temperature annealing effectiveness for recovery of radiation-induced structural changes and properties of 18Cr-10Ni-Ti austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Gurovich, B. A.; Kuleshova, E. A.; Frolov, A. S.; Maltsev, D. A.; Prikhodko, K. E.; Fedotova, S. V.; Margolin, B. Z.; Sorokin, A. A.

    2015-10-01

    A complex study of structural state and properties of 18Cr-10Ni-Ti austenitic stainless steel after irradiation in BOR-60 fast research reactor (in the temperature range 330-400 °С up to damaging doses of 145 dpa) and in VVER-1000 light water reactor (at temperature ∼320 °С and damaging doses ∼12-14 dpa) was performed. The possibility of recovery of structural-phase state and mechanical properties to the level almost corresponding to the initial state by the recovery annealing was studied. The principal possibility of the recovery annealing of pressurized water reactor internals that ensures almost complete recovery of its mechanical properties and microstructure was shown. The optimal mode of recovery annealing was established: 1000 °C during 120 h.

  12. An investigation on the role of texture evolution and ordered phase transition in soft magnetic properties of Fe-6.5 wt%Si electrical steel

    NASA Astrophysics Data System (ADS)

    Cai, Guojun; Li, Changsheng; Cai, Ban; Wang, Qiwen

    2017-05-01

    Fe-6.5 wt%Si electrical steel characterized with excellent soft magnetic properties such as almost zero magnetostriction, low eddy current and hysteresis losses characteristics has been widely applied in high frequency fields. In this work, the role of texture evolution and ordered phase transition in soft magnetic properties of annealed sheets was explored using EBSD, XRD and TEM. The results demonstrate that accompanied with the increase of annealing temperatures, an increase on the B8 is attributable to a contribution combining the sizes of recrystallization grains with APBs of ordered phases as pinning the migration of magnetic domain wall. Whereas B50 declines to a minimum value (1.479 T) and then increases to a certain value (1.695 T) due to different types and intensities of textures affecting on the magnetocrystalline anisotropy energy. Meanwhile, the dislocation density gradually decreases and corresponding to a gradual decline in the internal stress, which makes the coercive force (Hc) decrease monotonically.

  13. Use of cyclic current reversal polarization voltammetry for investigating the relationship between corrosion resistance and heat-treatment induced variations in microstructures of 400 C martensitic stainless steels

    NASA Technical Reports Server (NTRS)

    Ambrose, John R.

    1992-01-01

    Software for running a cyclic current reversal polarization voltammagram has been developed for use with a EG&G Princeton Applied Research Model 273 potentiostat/galvanostat system. The program, which controls the magnitude, direction and duration of an impressed galvanostatic current, will produce data in ASCII spreadsheets (Lotus, Quattro) for graphical representation of CCRPV voltammograms. The program was used to determine differences in corrosion resistance of 440 C martenstic stainless steel produced as a result of changes in microstructure effected by tempering. It was determined that tempering at all temperatures above 400 F resulted in increased polarizability of the material, with the increased likelihood that pitting would be initiated upon exposure to marine environments. These results will be used in development of remedial procedures for lowering the susceptibility of these alloys toward the stress corrosion cracking experienced in bearings used in high pressure oxygen turbopumps used in the main engines of space shuttle orbiters.

  14. Ageing of plasma-mediated coatings with embedded silver nanoparticles on stainless steel: An XPS and ToF-SIMS investigation

    NASA Astrophysics Data System (ADS)

    Zanna, S.; Saulou, C.; Mercier-Bonin, M.; Despax, B.; Raynaud, P.; Seyeux, A.; Marcus, P.

    2010-09-01

    Nanocomposite thin films (˜170 nm), composed of silver nanoparticles enclosed in an organosilicon matrix, were deposited onto stainless steel, with the aim of preventing biofilm formation. The film deposition was carried out under cold plasma conditions, combining radiofrequency (RF) glow discharge fed with argon and hexamethyldisiloxane and simultaneous silver sputtering. XPS and ToF-SIMS were used to characterize Ag-organosilicon films in native form and after ageing in saline solution (NaCl 0.15 M), in order to further correlate their lifetime with their anti-fouling properties. Two coatings with significantly different silver contents (7.5% and 20.3%) were tested. Surface analysis confirmed the presence of metallic silver in the pristine coating and revealed significant modifications after immersion in the saline solution. Two different ageing mechanisms were observed, depending on the initial silver concentration in the film. For the sample exhibiting the low silver content (7.5%), the metal amount decreased at the surface in contact with the solution, due to the release of silver from the coating. As a result, after a 2-day exposure, silver nanoparticles located at the extreme surface were entirely released, whereas silver is still present in the inner part of the film. The coating thickness was not modified during ageing. In contrast, for the high silver content film (20.3%), the thickness decreased with immersion time, due to significant silver release and matrix erosion, assigned to a percolation-like effect. However, after 18 days of immersion, the delamination process stopped and a thin strongly bounded layer remained on the stainless steel surface.

  15. Metallography of maraging 350 steel

    SciTech Connect

    Hutson, S.M.; Merten, C.W.

    1987-01-01

    A technique for etching maraging 350 steel with Glyceregia is described. Surface activation procedures are integral to this technique. Microstructural features revealed by this technique are compared with those obtained with Kalling's reagent, Fry's reagent, and 5% Nital, three etchants commonly used to reveal microstructures of maraging steels. Features which may be simultaneously revealed using Glyceregia include prior austenite grain boundaries, martensitic structure, precipitates, titanium carbo-nitrides, and reverted austenite. The other etchants examined in this investigation typically reveal only a few of the microstructural features detailed above at any one time. 11 refs., 10 figs., 2 tabs.

  16. The evolution of internal stress and dislocation during tensile deformation in a 9Cr ferritic/martensitic (F/M) ODS steel investigated by high-energy X-rays

    SciTech Connect

    Zhang, Guangming; Zhou, Zhangjian; Mo, Kun; Miao, Yinbin; Liu, Xiang; Almer, Jonathan; Stubbins, James F.

    2015-12-01

    An application of high-energy wide angle synchrotron X-ray diffraction to investigate the tensile deformation of 9Cr ferritic/martensitic (F/M) ODS steel is presented. With tensile loading and in-situ Xray exposure, the lattice strain development of matrix was determined. The lattice strain was found to decrease with increasing temperature, and the difference in Young's modulus of six different reflections at different temperatures reveals the temperature dependence of elastic anisotropy. The mean internal stress was calculated and compared with the applied stress, showing that the strengthening factor increased with increasing temperature, indicating that the oxide nanoparticles have a good strengthening impact at high temperature. The dislocation density and character were also measured during tensile deformation. The dislocation density decreased with increasing of temperature due to the greater mobility of dislocation at high temperature. The dislocation character was determined by best-fit methods for different dislocation average contrasts with various levels of uncertainty. The results shows edge type dislocations dominate the plastic strain at room temperature (RT) and 300 C, while the screw type dislocations dominate at 600 C. The dominance of edge character in 9Cr F/M ODS steels at RT and 300 C is likely due to the pinning effect of nanoparticles for higher mobile edge dislocations when compared with screw dislocations, while the stronger screw type of dislocation structure at 600 C may be explained by the activated cross slip of screw segments.

  17. Strain hardening of steel EP836

    SciTech Connect

    Lyadskaya, A.A.; Lappa, R.M.; Spuskanyuk, V.Z.

    1986-03-01

    The authors investigate the effect of different combinations of cold hydraulic pressing and heat treatment on the physical and mechanical properties of steel EP836 (03N17K10V10MT), containing 0.03% C, 16-17% Ni, 10-11.5% Co, 9.5-11.5% W, 1% Ti, 1% Mo, and 0.15% A1. Deformation of the unaged steel resulted in insignificant hardening without a decrease in plasticity; this agrees with the results of investigations of other steels of this class.

  18. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  19. Welding Rustproof Steels

    NASA Technical Reports Server (NTRS)

    Hoffmann, W

    1929-01-01

    The following experimental results will perhaps increase the knowledge of the process of welding rustproof steels. The experiments were made with two chrome-steel sheets and with two chrome-steel-nickel sheets having the composition shown in Table I.

  20. An Investigation on the Tribological Performances of the SiO2/MoS2 Hybrid Nanofluids for Magnesium Alloy-Steel Contacts.

    PubMed

    Xie, Hongmei; Jiang, Bin; Liu, Bo; Wang, Qinghang; Xu, Junyao; Pan, Fusheng

    2016-12-01

    Hybrid nano-materials offer potential scope for an increasing numerous novel applications when engineered to deliver availably functional properties. In the present study, the SiO2/MoS2 hybrid nanoparticles with different mass ratios were employed as lubricant additives in the base oil, and their tribological properties were evaluated using a reciprocating ball-on-plate tribometer for magnesium alloy-steel contacts. The results demonstrate that the SiO2/MoS2 hybrid nanoparticles exhibit superior lubrication performances than individual nano-SiO2 or nano-MoS2 even in high load and diverse velocity cases. The optimal SiO2/MoS2 mixing ratio and the concentration of SiO2/MoS2 hybrid nanoparticles in the base oil are 0.25:0.75 and 1.00-1.25 wt%, respectively. The excellent lubrication properties of the SiO2/MoS2 hybrid nanoparticles are attributed to the physical synergistic lubricating actions of nano-SiO2 and nano-MoS2 during the rubbing process.

  1. Simultaneous Investigation of the Effect of Advanced Thermomechanical Treatment and Repetitive Cyclic Voltammetry on the Electrochemical Behavior of AISI 430 Ferritic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Vafaeian, Saeed; Fattah-alhosseini, Arash; Keshavarz, Mohsen K.; Mazaheri, Yousef

    2017-01-01

    In this study, it was revealed that the electrochemical behavior of AISI 430 ferritic stainless steel can be modified and improved to a large extent by the application of repetitive cyclic voltammetry in the anodic polarization branch of the alloy. The efficiency of this method was evaluated on the basis of the alloy grain size which is of great importance in corrosion studies. In fact, a coarse grain structure versus a fine grain structure was the subject of the used surface treatment method. Coarsening and refining of the grain size were conducted through a heat treatment and an advanced thermomechanical process. On the basis of cyclic voltammetry tests and also the electrochemical tests performed after that, it was shown that cyclic voltammetry had a significant improving effect on the passive behavior of both fine- and coarse-grained samples. Moreover, superior behavior of fine-grained sample in comparison with coarse-grained one was distinguished by its smaller cyclic voltammogram loops, more noble free potentials, larger capacitive arcs in the Nyquist plots, and less charge carrier densities within the passive film.

  2. Investigation of respirable particulate matter pollutants on air-breathing zone workers in the Beam Rolling Mills Factory (Iran National Steel Industrial Group), Ahvaz, Iran

    PubMed Central

    Rafiei, Masoud; Gadgil, Alaka S.; Ghole, Vikram S.; Jaafarzadeh, Neemat; Gore, Sharad D.; Aberomand, Mohammad; Shabab, Mitra

    2008-01-01

    Workers of iron and steel factories are exposed to a wide range of pollutants depending on the particular process, the materials involved, the effectiveness of monitoring and the control measures. Adverse effects are determined by the physical state and propensities of the pollutant involved, the intensity and duration of the exposure, the extent of pollutant accumulation in the body and the sensitivity of the individual to its effects. The main aim of this study is to assess the levels of the indoor respirable particulate matter (RPM) and to compare the health condition of exposed workers, with nonexposed employees group. Line 630 has only one furnace of 40 tons and line 650 has two furnaces of 20 and 40 tons capacity due to which the mean of the RPM concentrations in the breathing zone was significantly different (P < 0.05) in line 650 but not in line 630 as compared with National Institute for Occupational Safety and Hygiene's (3 mg/m3). The average of the RPM concentrations in production line 650 is higher than that of production line 630, with the 95% confidence interval in saw cabin station number 1 of production line 650. PMID:20040982

  3. Investigation on the Effect of Mold Constraints and Cooling Rate on Residual Stress During the Sand-Casting Process of 1086 Steel by Employing a Thermomechanical Model

    NASA Astrophysics Data System (ADS)

    Baghani, Amir; Davami, Parviz; Varahram, Naser; Shabani, Mohsen Ostad

    2014-06-01

    In this study, the effects of mold constraints and cooling rate on residual stress were analyzed during the shaped casting process. For this purpose, an H-shaped sample was designed in which the contraction of its middle portion is highly restricted by the mold during the cooling process. The effects of an increasing cooling rate combined with mold constraints were analyzed by reducing the thickness of the middle portion in the second sample. A three-dimensional coupled temperature-displacement analysis was performed in finite-element code ABAQUS to simulate residual stress distribution, and then numerical results were verified by the hole-drilling strain-gauge method. It was concluded that the mold constraints have a greater effect on the values of residual stress than the cooling rate (thin section) in steel sand casting. Increasing the cooling rate would increase the amount of residual stress, only in the presence of mold constraints. It is also suggested that employing the elastic-plastic stress model for the sand mold will satisfy the experimental results and avoid exaggerated values of residual stress in simulation.

  4. An Investigation on the Tribological Performances of the SiO2/MoS2 Hybrid Nanofluids for Magnesium Alloy-Steel Contacts

    NASA Astrophysics Data System (ADS)

    Xie, Hongmei; Jiang, Bin; Liu, Bo; Wang, Qinghang; Xu, Junyao; Pan, Fusheng

    2016-07-01

    Hybrid nano-materials offer potential scope for an increasing numerous novel applications when engineered to deliver availably functional properties. In the present study, the SiO2/MoS2 hybrid nanoparticles with different mass ratios were employed as lubricant additives in the base oil, and their tribological properties were evaluated using a reciprocating ball-on-plate tribometer for magnesium alloy-steel contacts. The results demonstrate that the SiO2/MoS2 hybrid nanoparticles exhibit superior lubrication performances than individual nano-SiO2 or nano-MoS2 even in high load and diverse velocity cases. The optimal SiO2/MoS2 mixing ratio and the concentration of SiO2/MoS2 hybrid nanoparticles in the base oil are 0.25:0.75 and 1.00-1.25 wt%, respectively. The excellent lubrication properties of the SiO2/MoS2 hybrid nanoparticles are attributed to the physical synergistic lubricating actions of nano-SiO2 and nano-MoS2 during the rubbing process.

  5. An Experimental Investigation on the Effect of Addition of Ternary Blend on the Mix Design Characteristics of High Strength Concrete using Steel Fibre

    NASA Astrophysics Data System (ADS)

    Sinha, Deepa A., Dr; Verma, A. K., Dr

    2017-08-01

    This paper presents the results of M60 grade of concrete. M60 grade of concrete is achieved by maximum density technique. Concrete is brittle and weak in tension and develops cracks during curing and due to thermal expansion / contraction over a period ot time. Thus the effect of addition of 1% steel fibre is studied. For ages, concrete has been one of the widely used materials for construction. When cement is manufactured, every one ton of cement produces around one ton of carbon dioxide leading to global warming and also as natural resources are finishing, so use of supplementary cementitious material like alccofine and flyash is used as partial replacement of cement is considered. The effect of binary and ternary blend on the strength characteristics is studied. The results indicate that the concrete made with alccofine and flyash generally show excellent fresh and hardened properties. The ternary system that is Portland cement-fly ash-Alccofine concrete was found to increase the strength of concrete when compared to concrete made with Portland cement or even from Portland cement and fly ash.

  6. Simultaneous Investigation of the Effect of Advanced Thermomechanical Treatment and Repetitive Cyclic Voltammetry on the Electrochemical Behavior of AISI 430 Ferritic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Vafaeian, Saeed; Fattah-alhosseini, Arash; Keshavarz, Mohsen K.; Mazaheri, Yousef

    2017-02-01

    In this study, it was revealed that the electrochemical behavior of AISI 430 ferritic stainless steel can be modified and improved to a large extent by the application of repetitive cyclic voltammetry in the anodic polarization branch of the alloy. The efficiency of this method was evaluated on the basis of the alloy grain size which is of great importance in corrosion studies. In fact, a coarse grain structure versus a fine grain structure was the subject of the used surface treatment method. Coarsening and refining of the grain size were conducted through a heat treatment and an advanced thermomechanical process. On the basis of cyclic voltammetry tests and also the electrochemical tests performed after that, it was shown that cyclic voltammetry had a significant improving effect on the passive behavior of both fine- and coarse-grained samples. Moreover, superior behavior of fine-grained sample in comparison with coarse-grained one was distinguished by its smaller cyclic voltammogram loops, more noble free potentials, larger capacitive arcs in the Nyquist plots, and less charge carrier densities within the passive film.

  7. Investigation of the Kinetics of the Ferrite/Austenite Phase Transformation in the HAZ of a 2205 Duplex Stainless Steel Weldment

    SciTech Connect

    Palmer, T A; Elmer, J W; Wong, J; Babu, S S; Vitek, J M

    2002-03-14

    A semi-quantitative map based on a series of spatially resolved X-ray diffraction (SRXRD) scans shows the progression of the ferrite ({delta})/austenite ({gamma}) phase balance throughout the HAZ during GTA welding of a 2205 duplex stainless steel (DSS). This map shows an unexpected decrease in the ferrite fraction on heating, followed by a recovery to the original ferrite fraction on cooling at locations within the HAZ. Even though such behavior is supported by thermodynamic calculations, it has not been confirmed by either experimental methods or have the kinetics been evaluated. Both Gleeble thermal simulations and time resolved x-ray diffraction measurements on spot welds in the 2205 DSS provide further evidence for this rather low-temperature transformation. On the other hand, calculations of the diffusion of alloying elements across the 6/y interface under a variety of conditions shed no further light on the driving force for this transformation. Further work on the mechanisms and driving forces for this transformation is on-going.

  8. Radioactive waste isolation in salt: Peer review of the Office of Nuclear Waste Isolation's draft report on a multifactor test design to investigate uniform corrosion of low-carbon steel

    SciTech Connect

    Paddock, R.A.; Lerman, A.; Ditmars, J.D.; Macdonald, D.D.; Peerenboom, J.P.; Was, G.S.; Harrison, W.

    1987-01-01

    This report documents Argonne National Laboratory's review of an internal technical memorandum prepared by Battelle Memorial Institute's Office of Nuclear Waste Isolation (ONWI) entitled Multifactor Test Design to Investigate Uniform Corrosion of Low-Carbon Steel in a Nuclear Waste Salt Repository Environment. The several major areas of concern identified by peer review panelists are important to the credibility of the test design proposed in the memorandum and are to adequately addressed there. These areas of concern, along with specific recommendations to improve their treatment, are discussed in detail in Sec. 2 of this report. The twenty recommendations, which were abstracted from those discussions, are presented essentially in the order in which they are introduced in Sec. 2.

  9. 78 FR 79670 - Steel Threaded Rod From Thailand: Preliminary Determination of Sales at Less Than Fair Value and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ...] [FR Doc No: 2013-31341] DEPARTMENT OF COMMERCE International Trade Administration [A-549-831] Steel... (the ``Department'') preliminarily determines that steel threaded rod from Thailand is being, or is...: Scope of the Investigation The merchandise covered by this investigation is steel threaded rod. Steel...

  10. Effect of steel metallurgy on it magneto-mechanical behavior in weak magnetic fields

    SciTech Connect

    Robertson, I.M. )

    1994-03-01

    The magneto-mechanical behavior of five steels, mild steel, HSLA 80, HY100 and a quenched alloy steel, has been investigated. Magnetic fields of the order of the Earth's field and compressive stresses up to 200 MPa were applied to the steels. The increase in magnetization due to stress cycling in a constant applied field and to field cycling at constant stress was measured. The results show that the differential permeability of the steel largely determines the magnetization increase and that steels with similar microstructures have similar microstructures have similar magneto-mechanical response. The strength or hardness of the steel is a less reliable indicator of magneto-mechanical response.

  11. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-02

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  12. Methods of forming steel

    DOEpatents

    Branagan, Daniel J.; Burch, Joseph V.

    2001-01-01

    In one aspect, the invention encompasses a method of forming a steel. A metallic glass is formed and at least a portion of the glass is converted to a crystalline steel material having a nanocrystalline scale grain size. In another aspect, the invention encompasses another method of forming a steel. A molten alloy is formed and cooled the alloy at a rate which forms a metallic glass. The metallic glass is devitrified to convert the glass to a crystalline steel material having a nanocrystalline scale grain size. In yet another aspect, the invention encompasses another method of forming a steel. A first metallic glass steel substrate is provided, and a molten alloy is formed over the first metallic glass steel substrate to heat and devitrify at least some of the underlying metallic glass of the substrate.

  13. Investigation of a Novel NDE Method for Monitoring Thermomechanical Damage and Microstructure Evolution in Ferritic-Martensitic Steels for Generation IV Nuclear Energy Systems

    SciTech Connect

    Nagy, Peter

    2013-09-30

    The main goal of the proposed project is the development of validated nondestructive evaluation (NDE) techniques for in situ monitoring of ferritic-martensitic steels like Grade 91 9Cr-1Mo, which are candidate materials for Generation IV nuclear energy structural components operating at temperatures up to ~650{degree}C and for steam-generator tubing for sodium-cooled fast reactors. Full assessment of thermomechanical damage requires a clear separation between thermally activated microstructural evolution and creep damage caused by simultaneous mechanical stress. Creep damage can be classified as "negligible" creep without significant plastic strain and "ordinary" creep of the primary, secondary, and tertiary kind that is accompanied by significant plastic deformation and/or cavity nucleation and growth. Under negligible creep conditions of interest in this project, minimal or no plastic strain occurs, and the accumulation of creep damage does not significantly reduce the fatigue life of a structural component so that low-temperature design rules, such as the ASME Section III, Subsection NB, can be applied with confidence. The proposed research project will utilize a multifaceted approach in which the feasibility of electrical conductivity and thermo-electric monitoring methods is researched and coupled with detailed post-thermal/creep exposure characterization of microstructural changes and damage processes using state-of-the-art electron microscopy techniques, with the aim of establishing the most effective nondestructive materials evaluation technique for particular degradation modes in high-temperature alloys that are candidates for use in the Next Generation Nuclear Plant (NGNP) as well as providing the necessary mechanism-based underpinnings for relating the two. Only techniques suitable for practical application in situ will be considered. As the project evolves and results accumulate, we will also study the use of this technique for monitoring other GEN IV

  14. Thermal treatment of dissimilar steels' welded joints

    NASA Astrophysics Data System (ADS)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  15. Improved High Strength Armor Steel through Texturing

    DTIC Science & Technology

    1979-09-01

    80 I 14 02w INTRODUCTION During metal manufacturing processing, such as rolling of sheet and plate, the polycrystalline aggregate of the material...of the quenched martensite has been documented by previous investigators including Kula and Dhosi who ob- served that thermomechanical processing can...textured armor steel exhibits improved ballistic resistance to conventionally uncontrolled rolled steels of equal hardness at normal obliquity. This

  16. Microbially induced corrosion of carbon steel in deep groundwater environment

    PubMed Central

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  17. Automated Steel Cleanliness Analysis Tool (ASCAT)

    SciTech Connect

    Gary Casuccio; Michael Potter; Fred Schwerer; Dr. Richard J. Fruehan; Dr. Scott Story

    2005-12-30

    or bloom disposition; and alloy development. Additional benefits of ASCAT include the identification of inclusions that tend to clog nozzles or interact with refractory materials. Several papers outlining the benefits of the ASCAT have been presented and published in the literature. The paper entitled ''Inclusion Analysis to Predict Casting Behavior'' was awarded the American Iron and Steel Institute (AISI) Medal in 2004 for special merit and importance to the steel industry. The ASCAT represents a quantum leap in inclusion analysis and will allow steel producers to evaluate the quality of steel and implement appropriate process improvements. In terms of performance, the ASCAT (1) allows for accurate classification of inclusions by chemistry and morphological parameters, (2) can characterize hundreds of inclusions within minutes, (3) is easy to use (does not require experts), (4) is robust, and (5) has excellent image quality for conventional SEM investigations (e.g., the ASCAT can be utilized as a dual use instrument). In summary, the ASCAT will significantly advance the tools of the industry and addresses an urgent and broadly recognized need of the steel industry. Commercialization of the ASCAT will focus on (1) a sales strategy that leverages our Industry Partners; (2) use of ''technical selling'' through papers and seminars; (3) leveraging RJ Lee Group's consulting services, and packaging of the product with a extensive consulting and training program; (4) partnering with established SEM distributors; (5) establishing relationships with professional organizations associated with the steel industry; and (6) an individualized plant by plant direct sales program.

  18. Maraging Steel Machining Improvements

    DTIC Science & Technology

    2007-04-23

    APR 2007 2. REPORT TYPE Technical, Success Story 3. DATES COVERED 01-12-2006 to 23-04-2007 4. TITLE AND SUBTITLE Maraging Steel Machining...consumers of cobalt-strengthened maraging steel . An increase in production requires them to reduce the machining time of certain operations producing... maraging steel ; Success Stories 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 1 18. NUMBER OF PAGES 1 19a. NAME OF RESPONSIBLE

  19. Welding irradiated stainless steel

    SciTech Connect

    Kanne, W.R. Jr.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-12-31

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials.

  20. Diffusion bonding between ODS ferritic steel and F82H steel for fusion applications

    NASA Astrophysics Data System (ADS)

    Noh, Sanghoon; Kim, Byungjun; Kasada, Ryuta; Kimura, Akihiko

    2012-07-01

    Diffusion bonding techniques were employed to join high Cr oxide dispersion strengthened (ODS) ferritic steel (Fe-15Cr-2W-0.2Ti-0.35Y2O3) and F82H steel under uni-axial hydrostatic pressure using a high vacuum hot press, and the microstructure and mechanical properties of the joints were investigated. The dissimilar joints were bonded by solid-state diffusion bonding (SSDB) and liquid phase diffusion bonding (LPDB). After bonding process, heat treatments were conducted to utilize the phase transformation of F82H steel for recovering the martensitic structure. Tensile tests with miniaturized specimens were carried out to investigate and compare the bonding strengths of each joint. Microstructure was observed for the bonding interface, and fracture mode was investigated after the tensile tests. LPDB joint of interfacial F82H steel fully recovered to martensite phase by post-joining heat treatments, while SSDB joint had ferrite phases at the interface even after heat treatment, which is considered to be due to decarburization of F82H steel during the bonding process. Therefore it is considered that the insert material plays a role as diffusion barrier of carbon during LPDB process. Microstructure observations and tensile tests of the joints revealed that the LPDB joints possess suitable tensile properties which are comparable to that of F82H steel. This indicates that LPDB is more promising method to bond ODS-FS and F82H steel than SSDB.

  1. 78 FR 46570 - Suspension Agreement on Certain Cut-to-Length Carbon Steel Plate From Ukraine; Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... International Trade Administration Suspension Agreement on Certain Cut-to-Length Carbon Steel Plate From Ukraine... & Steel Works (Azovstal) and Ilyich Iron and Steel Works (Ilyich), are in compliance with the agreement suspending the antidumping investigation of certain cut-to-length carbon steel plate (CTL plate) from...

  2. DETECTION OF BACTERIAL BIOFILM ON STAINLESS STEEL BY HYPERSPECTRAL FLUORESCENCE IMAGING

    USDA-ARS?s Scientific Manuscript database

    In this study, hyperspectral fluorescence imaging techniques were investigated for detection of microbial biofilm on stainless steel plates typically used to manufacture food processing equipment. Stainless steel coupons were immersed in bacterium cultures consisting of nonpathogenic E. coli, Pseudo...

  3. Abbreviated annealing of high-speed steel

    SciTech Connect

    Zablotskii, V.K.; Bartel, G.P.

    1987-07-01

    The authors investigate the structural and phase transformations during the heating, holding, and cooling of high-speed steels of two basic groups: tungsten (R18, R12, R12F3, and R12F4K5) and tungsten-molybdenum (R6M5, 10R6M5, R6M5K5, R8M3, 10R8M3, and R8M3K6S) steels in the forged state. They propose a cooling regime with complete alpha-gamma recrystallization whose implementation at a Soviet steel plant has made it possible to reduce the duration of heat treatment and increase productivity by 20% in cutting the annealed high-speed steels.

  4. Determination of the Transverse Properties of ESR 4340 Steel.

    DTIC Science & Technology

    1980-09-01

    PROPERTIES OF ESR 4340 STEEL SEPTEMBER 1980 D TIC ELECTE John T. Berry JAN 2 2 1981, School of Mechanical Engineering 0 Georgia Institute of Technology...of the Transverse Properties of ESR 4340 Steel Covering period from August 3, 1978 to June 20, 1980. DATED: June 20, 1980 John T. Berry S. Peter Kezios...the plates, a thorough investigation was performed with respect to fabricating and testing AISI 4340 steel DLT bars. Materials from previous ESR 4340

  5. The Steel Band.

    ERIC Educational Resources Information Center

    Weil, Bruce

    1996-01-01

    Describes studying the steel drum, an import from Trinidad, as an instrument of intellectual growth. Describes how developing a steel drum band provided Montessori middle school students the opportunity to experience some important feelings necessary to emotional growth during this difficult age: competence, usefulness, independence, and…

  6. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  7. High Nitrogen Stainless Steel

    DTIC Science & Technology

    2011-07-19

    Hydrogen Embrittlement in Steel by the Increment Loading Technique. Fractography: After the stress-life fatigue tests, the fracture surface morphology...study was conducted to clarify the mechanical properties and stress corrosion cracking (SCC) resistance of high nitrogen stainless steel (HNSS) plates...Corrosion Cracking 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON

  8. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  9. Thermal helium desorption behavior in advanced ferritic steels

    NASA Astrophysics Data System (ADS)

    Kimura, Akihiko; Sugano, R.; Matsushita, Y.; Ukai, S.

    2005-02-01

    Thermal helium desorption measurements were performed to investigate the difference in the helium trapping and accumulation behavior among a reduced activation ferritic (RAF) steel and oxide dispersion strengthening (ODS) steels after implantation of He+ ions at room temperature. Thermal helium desorption spectra (THDS) were obtained during annealing to 1200 °C at a heating rate of 1 °C/s. The THDS of the ODS steels are very similar to that of the RAF steel, except for the presence of the peak in the temperature range from 800 to 1000 °C, where the α γ transformation related helium desorption from the γ-phase is considered to occur in the 9Cr-ODS martensitic steels. The fraction of helium desorption becomes larger at higher temperatures, and this trend is increased with the amount of implanted helium. In the 9Cr-ODS steels, the fraction of helium desorption by bubble migration mechanism was smaller than that in the RAF steel. This suggests that the bubble formation was suppressed in the ODS steels. In the 12Cr-ODS steel, the fraction of helium desorption by bubble migration reached more than 90%, suggesting that the trapping capacity of martensite phase in the 9Cr-ODS steel is rather large.

  10. Experimental investigation of egg ovalbumin scaling on heated stainless steel surface and scale-removal compared with that of whey protein.

    PubMed

    Li, Lin; Lv, Hui Ting; Deng, Ren Pan; Liao, Zhen Kai; Wu, Xue E; Chen, Xiao Dong

    2013-07-01

    Fouling and cleaning on a heat exchanger surface during milk processing have been studied extensively in the past due to their great importance in energy, product quality, and safety. However, little information is available for egg ovalbumin (OVA) fouling and cleaning behavior. In the present work, fouling and cleaning behaviors of OVA were investigated using a real-time monitoring system for heat transfer coefficient. A comparison was made between the behavior of whey protein concentrate (WPC) and that of OVA. WPC has been well studied which can be used as a benchmark. Ultrasonic cleaning was also applied to investigate the cleaning behavior of OVA fouling. Results have shown that OVA created more thermal resistance than WPC in the 2 h fouling process. It was also much more difficult to remove the OVA deposit than the WPC fouling. Different from what were observed from WPC deposit, there was no optimal cleaning rate for OVA deposit in the NaOH concentration range tested (0-2.0 wt%), while WPC fouling is known to have the highest cleaning rate around 0.5 wt% NaOH concentration at moderate temperatures.

  11. EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, BUFFALO PLANT. VIEW LOOKING SOUTHWEST FROM ROLL SHOP. 8" BAR MILL DESIGNED AND BUILT BY DONNER STEEL CO. (PREDECESSOR OF REPUBLIC), 1919-1920. FOR DESCRIPTION OF ORIGINAL MILL SEE "IRON AGE", 116\\4 (23 JULY 1925): 201-204. - LTV Steel, 8-inch Bar Mill, Buffalo Plant, Buffalo, Erie County, NY

  12. Investigation of Phase Transformations in High-Alloy Austenitic TRIP Steel Under High Pressure (up to 18 GPa) by In Situ Synchrotron X-ray Diffraction and Scanning Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Ackermann, Stephanie; Martin, Stefan; Schwarz, Marcus R.; Schimpf, Christian; Kulawinski, Dirk; Lathe, Christian; Henkel, Sebastian; Rafaja, David; Biermann, Horst; Weidner, Anja

    2016-01-01

    In order to clarify the difference between the deformation-induced ɛ-martensite ( ɛ 1) and the pressure-induced ɛ-iron ( ɛ 2), high-pressure quasi-hydrostatic experiments were performed on a low-carbon, high-alloy metastable austenitic steel. In situ synchrotron X-ray diffraction measurements as well as post-mortem investigations of the microstructure by electron backscatter diffraction were carried out to study the microstructural transformations. Three processes were observed during compression experiments: first, the formation of deformation-induced hexagonal ɛ 1-martensite, as well as small nuclei of deformation-induced bcc α'-martensite ( α 1') within the fcc γ-matrix due to non-hydrostaticity in the experiments; second, the onset of the phase transformation from the metastable fcc γ-austenite into the hexagonal pressure-induced ɛ 2-iron phase occurred at around 6 GPa; third, during decompression, the hexagonal pressure-induced ɛ 2-iron transformed partially into bcc α'-martensite ( α 2'). Completely different characteristics with regard to habitus as well as to orientation relationships were observed between the pressure-induced phases ( ɛ 2-iron phase and α 2'-martensite) and the deformation-induced martensites ( ɛ 1- and α 1'-martensite).

  13. Laboratory investigation of the microbiologically influenced corrosion (MIC) resistance of a novel Cu-bearing 2205 duplex stainless steel in the presence of an aerobic marine Pseudomonas aeruginosa biofilm.

    PubMed

    Xia, Jin; Yang, Chunguang; Xu, Dake; Sun, Da; Nan, Li; Sun, Ziqing; Li, Qi; Gu, Tingyue; Yang, Ke

    2015-01-01

    The microbiologically influenced corrosion (MIC) resistance of a novel Cu-bearing 2205 duplex stainless steel (2205 Cu-DSS) against an aerobic marine Pseudomonas aeruginosa biofilm was investigated. The electrochemical test results showed that Rp increased and icorr decreased sharply after long-term immersion in the inoculation medium, suggesting that 2205 Cu-DSS possessed excellent MIC resistance to the P. aeruginosa biofilm. Fluorescence microscope images showed that 2205 Cu-DSS possessed a strong antibacterial ability, and its antibacterial efficiency after one and seven days was 7.75% and 96.92%, respectively. The pit morphology comparison after 14 days between 2205 DSS and 2205 Cu-DSS demonstrated that the latter showed a considerably reduced maximum MIC pit depth compared with the former (1.44 μm vs 9.50 μm). The experimental results suggest that inhibition of the biofilm was caused by the copper ions released from the 2205 Cu-DSS, leading to its effective mitigation of MIC by P. aeruginosa.

  14. Thermal stability study for candidate stainless steels of GEN IV reactors

    NASA Astrophysics Data System (ADS)

    Simeg Veternikova, J.; Degmova, J.; Pekarcikova, M.; Simko, F.; Petriska, M.; Skarba, M.; Mikula, P.; Pupala, M.

    2016-11-01

    Candidate stainless steels for GEN IV reactors were investigated in term of thermal and corrosion stability at high temperatures. New austenitic steel (NF 709), austenitic ODS steel (ODS 316) and two ferritic ODS steels (MA 956 and MA 957) were exposed to around 1000 °C in inert argon atmosphere at pressure of ∼8 MPa. The steels were further studied in a light of vacancy defects presence by positron annihilation spectroscopy and their thermal resistance was confronted to classic AISI steels. The thermal strain supported a creation of oxide layers observed by scanning electron microscopy (SEM).

  15. Wear of Cast Chromium Steels With TiC Reinforcement

    SciTech Connect

    Dogan,O.N.; Hawk, J.A.; Tylczak, J.H.

    2001-10-01

    Wear resistance of a series of new titanium carbide reinforced cast chromium steels was investigated under various wear conditions. The steels which were melted in a vacuum induction furnace contained 12 Cr, 3-5 Ti, 1-2 C in weight percent. Microstructure of these materials was characterized using scanning electron microscopy, light optical microscopy, and X-ray diffraction. Microstructure of steels consisted of TiC phase dispersed in a martensitic matrix. High-stress and low-stress abrasion tests, and an erosion test, were utilized to understand the wear behavior of these materials under different environments. The steels were tested in as-cast and heat treated conditions. Wear rates of the cast Cr/TiC steels were compared to those of an AISI type 440C steel and P/M composites reinforced with TiC.

  16. Undervehicle corrosion testing of zinc and zinc alloy coated steels

    SciTech Connect

    Neville, R.J.; de Souza, K.M.

    1986-12-01

    Undervehicle and on-vehicle coupon corrosion test programs are initiated by Dofasco Inc. in 1981, using two commercial trucks operated in the deicing salt/snow belt area of Southern Ontario, Canada. The purpose was to investigate the relative corrosion performance of numerous zinc and zinc alloy coated steels. Seventeen coated steels were tested. Results to date indicate that the hot dip coated steels with the thicker coatings are outperforming the electrolytic coated steels in both the unpainted and phosphated/cathodic primed conditions. Fully painted on-vehicle test coupons show minimal corrosion and little difference to date.

  17. Production of ultra thin grain oriented silicon steel sheets

    SciTech Connect

    Nakano, M.; Ishiyama, K.; Arai, K.I.

    1995-11-01

    Grain texture and magnetic properties of ultra thin silicon steel sheets were investigated. The sheets were produced using two kinds of starting materials. One was conventional grain oriented silicon steel sheet and the other was hot rolled silicon steel. Ultra thin sheets were obtained by cold rolling with intermediate annealing. By annealing in a high vacuum a recrystallization using surface energy occurred and very sharp (110)[001] texture was obtained in sheets of 5--8 {micro}m thick. The B{sub 8} of the ultra thin silicon steel sheets obtained were over 1.95 T.

  18. Leaching of metals from steel samples in peracetic acid

    NASA Astrophysics Data System (ADS)

    Yabutani, Tomoki; Nakamura, Takamasa; Takayabagi, Toshio

    2015-03-01

    In this paper, leaching behavior of metallic species from steel samples in peracetic acid was investigated. We compared the leaching efficiency between peracetic acid and acetic acid to estimate the role of peroxo functional group for the leaching. As a result, peracetic acid enhanced the leaching ability of metallic species from the high speed steel and the alloy steel samples. MoO3, Mo, MO2C, W, WO3, VC and MnO2 were effectively leached by peracetic acid, while the stainless steel had a high resistance against corrosion by peracetic acid.

  19. The effect of microstructure on abrasive wear of steel

    NASA Astrophysics Data System (ADS)

    Kešner, A.; Chotëborský, R.; Linda, M.

    2017-09-01

    Abrasive wear of agricultural tools is one of the biggest problems in currently being. The amount of abrasive wear, depending on the microstructure, has been investigated in this work. Steels 25CrMo4 and 51CrV4 were used in this work to determine the effect of the microstructure on the abrasive wear. These steels are commonly used for components that have to withstand abrasive wear.SEM analysis was used to detect the microstructure. The standardized ASTM G65 method was used to compare the abrasive wear of steels. The results show that the abrasive wear depends on the microstructure of steels.

  20. Development of Steel Foam Materials and Structures

    SciTech Connect

    Kenneth Kremer; Anthony Liszkiewicz; James Adkins

    2004-10-20

    In the past few years there has been a growing interest in lightweight metal foams. Demands for weight reduction, improved fuel efficiency, and increased passenger safety in automobiles now has manufacturers seriously considering the use of metal foams, in contrast to a few years ago, when the same materials would have been ruled out for technical or economical reasons. The objective of this program was to advance the development and use of steel foam materials, by demonstrating the advantages of these novel lightweight materials in selected generic applications. Progress was made in defining materials and process parameters; characterization of physical and mechanical properties; and fabrication and testing of generic steel foam-filled shapes with compositions from 2.5 wt.% to 0.7 wt.% carbon. A means of producing steel foam shapes with uniform long range porosity levels of 50 to 60 percent was demonstrated and verified with NDE methods. Steel foam integrated beams, cylinders and plates were mechanically tested and demonstrated advantages in bend stiffness, bend resistance, and crush energy absorption. Methods of joining by welding, adhesive bonding, and mechanical fastening were investigated. It is important to keep in mind that steel foam is a conventional material in an unconventional form. A substantial amount of physical and mechanical properties are presented throughout the report and in a properties database at the end of the report to support designer's in applying steel foam in unconventional ways.

  1. Nickel-free duplex stainless steels

    SciTech Connect

    Wang, J.; Uggowitzer, P.J.; Magdowski, R.; Speidel, M.O.

    1998-12-04

    It is well known that nitrogen-alloying in steel produces a variety of exceptional properties such as high strength, high ductility and, eventually, resistance to stress corrosion cracking. High-nitrogen steels (HNS), therefore, have recently been developed to enhance the strength and corrosion resistance of stainless steels. However, due to a low solubility of nitrogen in a liquid steel under atmospheric pressure, the production of such high-nitrogen alloys needs high-pressure facilities that cause an extra cost. A possible route of developing high-nitrogen alloys under atmospheric pressure is to choose a duplex microstructure, where the amount of austenite and ferrite phase is nearly equal. A much lower nitrogen content is needed to maintain a 50% austenite phase compared with the necessary addition of nitrogen to reach a 100% austenitic microstructure. In addition, duplex stainless steels (DSS) with 40--60% ferrite can significantly improve the SCC-resistance. The objective of this work was to develop a new group of nickel-free, high strength and corrosion resistant DSS. Nickel was completely replaced by nitrogen in order to enhance SCC resistance and reduce the alloying element cost. The microstructure, mechanical properties, corrosion resistance and cost analysis of new alloys are investigated in comparison with some commercial stainless steels.

  2. Stainless steel recycle FY94 progress report

    SciTech Connect

    Imrich, K.J.

    1994-10-28

    The Materials Technology Section (MTS) of the Savannah River Technology Center (SRTC) was asked to demonstrate the practicality of recycling previously contaminated stainless steel components such as reactor heat exchanger heads, process water piping and slug buckets into 208 liters (55 gallon) drums and 2.8 cubic meter (100 ft{sup 3}) storage boxes. Radioactively contaminated stainless steel scrap will be sent to several industrial partners where it will be melted, decontaminated/cast into ingots, and rolled into plate and sheet and fabricated into the drums and boxes. As part of this recycle initiative, MTS was requested to demonstrate that radioactively contaminated Type 304L stainless steel could be remelted and cast to meet the applicable ASTM specification for fabrication of drums and boxes. In addition, MTS was requested to develop the technical basis of melt decontamination and establish practicality of using this approach for value added products. The findings presented in this investigation lead to the following conclusions: recycle of 18 wt% Cr-8 wt% Ni alloy can be achieved by melting Type 304 stainless steel in a air vacuum induction furnace; limited melt decontamination of the contaminated stainless steel was achieved, surface contamination was removed by standard decontamination techniques; carbon uptake in the as-cast ingots resulted from the graphite susceptor used in this experiment and is unavoidable with this furnace configuration. A new furnace optimized for melting stainless steel has been installed and is currently being tested for use in this program.

  3. Dissolution of steel slags in aqueous media.

    PubMed

    Yadav, Shashikant; Mehra, Anurag

    2017-07-01

    Steel slag is a major industrial waste in steel industries, and its dissolution behavior in water needs to be characterized in the larger context of its potential use as an agent for sequestering CO2. For this purpose, a small closed system batch reactor was used to conduct the dissolution of steel slags in an aqueous medium under various dissolution conditions. In this study, two different types of steel slags were procured from steel plants in India, having diverse structural features, mineralogical compositions, and particle sizes. The experiment was performed at different temperatures for 240 h of dissolution at atmospheric pressure. The dissolution rates of major and minor slag elements were quantified through liquid-phase elemental analysis using an inductively coupled plasma atomic emission spectroscopy at different time intervals. Advanced analytical techniques such as field emission gun-scanning electron microscope, energy-dispersive X-ray, BET, and XRD were also used to analyze mineralogical and structural changes in the slag particles. High dissolution of slags was observed irrespective of the particle size distribution, which suggests high carbonation potential. Concentrations of toxic heavy metals in the leachate were far below maximum acceptable limits. Thus, the present study investigates the dissolution behavior of different mineral ions of steel slag in aqueous media in light of its potential application in CO2 sequestration.

  4. Damascus steel ledeburite class

    NASA Astrophysics Data System (ADS)

    Sukhanov, D. A.; Arkhangelsky, L. B.; Plotnikova, N. V.

    2017-02-01

    Discovered that some of blades Damascus steel has an unusual nature of origin of the excess cementite, which different from the redundant phases of secondary cementite, cementite of ledeburite and primary cementite in iron-carbon alloys. It is revealed that the morphological features of separate particles of cementite in Damascus steels lies in the abnormal size of excess carbides having the shape of irregular prisms. Considered three hypotheses for the formation of excess cementite in the form of faceted prismatic of excess carbides. The first hypothesis is based on thermal fission of cementite of a few isolated grains. The second hypothesis is based on the process of fragmentation cementite during deformation to the separate the pieces. The third hypothesis is based on the transformation of metastable cementite in the stable of angular eutectic carbide. It is shown that the angular carbides are formed within the original metastable colony ledeburite, so they are called “eutectic carbide”. It is established that high-purity white cast iron is converted into of Damascus steel during isothermal soaking at the annealing. It was revealed that some of blades Damascus steel ledeburite class do not contain in its microstructure of crushed ledeburite. It is shown that the pattern of carbide heterogeneity of Damascus steel consists entirely of angular eutectic carbides. Believe that Damascus steel refers to non-heat-resistant steel of ledeburite class, which have similar structural characteristics with semi-heat-resistant die steel or heat-resistant high speed steel, differing from them only in the nature of excess carbide phase.

  5. 77 FR 23752 - Drawn Stainless Steel Sinks From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-20

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Drawn Stainless Steel Sinks From China Determinations On the basis of the record \\1\\ developed in... (April 2012), entitled Drawn Stainless Steel Sinks from China: Investigation Nos. 701-TA-489 and...

  6. Recommended Stainless Steel Welding Procedures for Corps of Engineers Construction.

    DTIC Science & Technology

    Two stainless steel welding methods are investigated for potential use in Corps of Engineers construction. The methods-gas tungsten-arc welding ( GTAW ...electron microscopy. Results show that GTAW and SMAW provide sound welds in the two stainless steels tested. Moreover, using low-carbon electrodes and

  7. Void nucleation in spheroidized steels during tensile deformation

    SciTech Connect

    Fisher, Jr, J R

    1980-04-01

    An investigation was conducted to determine the effects of various mechanical and material parameters on void formation at cementite particles in axisymmetric tensile specimens of spheroidized plain carbon steels. Desired microstructures for each of three steel types were obtained. Observations of void morphology with respect to various microstructural features were made using optical and scanning electron microscopy.

  8. Euler Teaches a Class in Structural Steel Design

    ERIC Educational Resources Information Center

    Boyajian, David M.

    2009-01-01

    Even before steel was a topic of formal study for structural engineers, the brilliant eighteenth century Swiss mathematician and physicist, Leonhard Euler (1707-1783), investigated the theory governing the elastic behaviour of columns, the results of which are incorporated into the American Institute of Steel Construction's (AISC's) Bible: the…

  9. Euler Teaches a Class in Structural Steel Design

    ERIC Educational Resources Information Center

    Boyajian, David M.

    2009-01-01

    Even before steel was a topic of formal study for structural engineers, the brilliant eighteenth century Swiss mathematician and physicist, Leonhard Euler (1707-1783), investigated the theory governing the elastic behaviour of columns, the results of which are incorporated into the American Institute of Steel Construction's (AISC's) Bible: the…

  10. A study of Damascus steel

    SciTech Connect

    Berge, P.

    1995-02-16

    The Damascus sword has been an article of fascination for many years to blade collectors and metallurgists alike. The blades were given their name by Europeans who encountered these blades which originated from Damascus, Syria. They are best known for the appearance of the blade face. Genuine Damascus blades show swirling patterns of alternating light and dark regions which are due to the microstructure of the steel. The microstructure consists of arrays of well rounded cementite patterns in a matrix of either pearlite, bainite, or martensite. When this structure is etched the matrix will turn dark leaving the cementite particles light. Although many blades were produced over the centuries, while some of the process is known the making of a genuine Damascus blade today is generally considered a lost art. Many scientists have studied the subject in an attempt to understand the complex process by which the clustered arrays of cementite particles develop in the steel blades. The most prominent theories to date are presented in the General Introduction to this thesis. The thesis is divided into four main parts. In the first part, four proposed mechanisms of cementite cluster sheet formation as they relate to the banding theory are introduced. Experiments to investigate these mechanisms are presented. In Part II, collaborative research focused on the methodology of the reconstructed process for making Damascus steel is presented. In the third part, a study into the graphitization of the reconstructed blades is presented. In Part IV, experimental attempts at producing Damascus steel ingots in the laboratory are presented.

  11. 78 FR 71565 - Steel Threaded Rod from India: Postponement of Preliminary Determination of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ... International Trade Administration Steel Threaded Rod from India: Postponement of Preliminary Determination of...'') published a notice of initiation of the antidumping duty investigation of steel threaded rod from India.\\1... later than December 20, 2013. \\1\\ See Steel Threaded Rod From India and Thailand: Initiation...

  12. 77 FR 73424 - Steel Wire Garment Hangers From Taiwan: Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... International Trade Administration Steel Wire Garment Hangers From Taiwan: Antidumping Duty Order AGENCY: Import... duty order on steel wire garment hangers from Taiwan. FOR FURTHER INFORMATION CONTACT: Paul Walker, AD... of sales at less than fair value in the antidumping duty investigation of steel wire garment...

  13. 76 FR 12369 - Porcelain-on-Steel Cooking Ware From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... COMMISSION Porcelain-on-Steel Cooking Ware From China Determination On the basis of the record \\1\\ developed... antidumping duty order on porcelain-on-steel cooking ware from China would be likely to lead to continuation... 2011), entitled Porcelain-on-Steel Cooking Ware from China: Investigation No. 731-TA- 298 (Third...

  14. 75 FR 59744 - Stainless Steel Plate From Belgium, Italy, Korea, South Africa, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... COMMISSION [Investigation Nos. 701-TA-376 and 379 and 731-TA-788, 790-793 (Second Review)] Stainless Steel... countervailing duty orders on stainless steel plate from Belgium and South Africa and the antidumping duty orders on stainless steel plate from Belgium, Italy, Korea, South Africa, and Taiwan. SUMMARY:...

  15. 77 FR 37377 - High Pressure Steel Cylinders From the People's Republic of China: Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-21

    ... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China... high pressure steel cylinders from the People's Republic of China (``PRC''). On June 14, 2012, the ITC... High Pressure Steel Cylinders from China (Investigation Nos. 701-TA-480 and 731-TA-1188 (Final),...

  16. 76 FR 59658 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China... antidumping duty investigation on high pressure steel cylinders from the People's Republic of China.\\1\\ The... is currently due no later than October 18, 2011. \\1\\ See High Pressure Steel Cylinders from...

  17. 77 FR 1060 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ... International Trade Administration High Pressure Steel Cylinders From the People's Republic of China... investigation on high pressure steel cylinders from the People's Republic of China (``PRC'').\\1\\ On December 15... the Preliminary Determination.\\3\\ \\1\\ See High Pressure Steel Cylinders from the People's Republic...

  18. 78 FR 73838 - Steel Concrete Reinforcing Bar From Turkey: Postponement of Preliminary Determination in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... International Trade Administration Steel Concrete Reinforcing Bar From Turkey: Postponement of Preliminary... Department of Commerce (the Department) initiated a countervailing duty investigation on steel concrete... December 16, 2013.\\3\\ \\1\\ See Steel Concrete Reinforcing Bar from Turkey: Initiation of Countervailing...

  19. 75 FR 36678 - Prestressed Concrete Steel Wire Strand From China; Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-28

    ... COMMISSION Prestressed Concrete Steel Wire Strand From China; Determinations On the basis of the record \\1... of prestressed concrete steel wire strand (PC strand), provided for in subheading 7312.10.30 of the... (June 2010), entitled Prestressed Concrete Steel Wire Strand from China: Investigation Nos....

  20. 76 FR 33242 - Galvanized Steel Wire From the People's Republic of China: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... International Trade Administration Galvanized Steel Wire From the People's Republic of China: Postponement of... of galvanized steel wire from the People's Republic of China. See Galvanized Steel Wire From the... investigation, Davis Wire Corporation, Johnstown Wire Technologies, Inc., Mid-South Wire Company, Inc., National...

  1. 75 FR 28560 - Prestressed Concrete Steel Wire Strand From the People's Republic of China: Final Determination...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... International Trade Administration Prestressed Concrete Steel Wire Strand From the People's Republic of China...'' section of this notice. \\1\\ See Prestressed Concrete Steel Wire Strand From the People's Republic of China...., Ltd. in the Antidumping Duty Investigation of Prestressed Concrete Steel Wire Strand From the...

  2. Effects of Ceric Oxide Coatings on Materials Performance of 430 Steel in Coal Synthetc Gas

    SciTech Connect

    Ziomek-Moroz, M. Jablonski, P

    2011-12-21

    The surfaces of low silicon and aluminum 430 stainless steel (UNS 43000) coupons with and without ceria (CeO2) surface treatment were investigated after exposure to simulated coal syngas based fuel at 800 C. The results indicate a different mechanism of carburization for the ceria treated steel than that for the untreated steel.

  3. Development of New Type Seawater Resistant Steel and the Research of Its Structure and Corrosion Resistance

    NASA Astrophysics Data System (ADS)

    Yin, Baoliang; Yin, Shaojiang; Liu, Zhiyong; Wang, Yunge; Yu, Hao; Li, Haixu; Zhou, Tao

    This paper investigated two kinds of corrosion resistant low alloy steels depending on the environment of the North China see (Steel S) and South China sea (Steel N), respectively. The mechanical and corrosion properties of the two steels were analyzed in this paper. Tin was added into both steels to improve the corrosion resistance. Structure and mechanical properties of the two steels were detected, and the results revealed that the microstructures of both steels were ferrite and little divorced pearlite. The yield strength and impact toughness at -40°C of the steel S are 423MPa and 98 J, respectively. The yield strength and impact toughness at -40°C of the steel N are 437 MPa and 70 J, respectively. The properties mentioned above met or even exceeded the requirement (yield strength 355 MPa, toughness 34 J) in these areas. The corrosion resistant properties of the two steels were also investigated via the means of immersion test and electrochemical experiment. The immersion test indicated that the corrosion rate of steel S and steel N was 0.00938 mg/h·cm2 and 0.00838 mg/h·cm2, respectively, when completely immersed for 168 hours, and the corrosion rate was much lower than that of E36. The Electrochemical experiments showed that the corrosion potential (Ecorr) of both steels was higher in contrast to E36, which indicated a lower corrosion trend.

  4. Residual Stress Effect on the Delayed Fracture of Twinning-Induced Plasticity Steels

    NASA Astrophysics Data System (ADS)

    Kim, Jung Gi; Yoon, Jae Ik; Baek, Seung Mi; Seo, Min Hong; Cho, Won Tae; Chin, Kwang-Geun; Lee, Sunghak; Kim, Hyoung Seop

    2017-03-01

    Residual stress effect of the deep drawn TWIP steel on delayed fracture was investigated. Microstructural features of the TWIP steels did not change after stress relief annealing, while the elastic lattice strain dropped to 0.0007. Delayed fracture of the drawn TWIP steel occurred after 203 hours of HCl immersion testing, but did not occur in the annealed one. It is clear that residual stress after the drawing is the primary reason for the delayed fracture of TWIP steels.

  5. Residual Stress Effect on the Delayed Fracture of Twinning-Induced Plasticity Steels

    NASA Astrophysics Data System (ADS)

    Kim, Jung Gi; Yoon, Jae Ik; Baek, Seung Mi; Seo, Min Hong; Cho, Won Tae; Chin, Kwang-Geun; Lee, Sunghak; Kim, Hyoung Seop

    2017-06-01

    Residual stress effect of the deep drawn TWIP steel on delayed fracture was investigated. Microstructural features of the TWIP steels did not change after stress relief annealing, while the elastic lattice strain dropped to 0.0007. Delayed fracture of the drawn TWIP steel occurred after 203 hours of HCl immersion testing, but did not occur in the annealed one. It is clear that residual stress after the drawing is the primary reason for the delayed fracture of TWIP steels.

  6. Steel Pickling Inspection Checklist

    EPA Pesticide Factsheets

    Checklist to establish whether a facility or operations within a facility are subject to and are in compliance with 40 C.F.R Part 63 Subpart CCC (Steel Pickling—HCl Process Facilities and Hydrochloric Acid Regeneration Plants NESHAP).

  7. Structural Amorphous Steels

    NASA Astrophysics Data System (ADS)

    Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

    2004-06-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

  8. Cobalt free maraging steel

    SciTech Connect

    Floreen, S.

    1984-04-17

    The subject invention is directed to ferrous-base alloys, particularly to a cobalt-free maraging steel of novel chemistry characterized by a desired combination of strength and toughness, notwithstanding that cobalt is non-essential.

  9. Glass Stronger than Steel

    DOE R&D Accomplishments Database

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  10. Mechanical characteristics of welded joints between different stainless steels grades

    NASA Astrophysics Data System (ADS)

    Topolska, S.; Łabanowski, J.

    2017-08-01

    Investigation of mechanical characteristics of welded joints is one of the most important tasks that allow determining their functional properties. Due to the very high, still rising, cost of some stainless steels it is justified, on economic grounds, welding austenitic stainless steel with steels that are corrosion-resistant like duplex ones. According to forecasts the price of corrosion resistant steels stil can increase by 26 ÷ 30%. For technical reasons welded joints require appropriate mechanical properties such as: tensile strength, bending, ductility, toughness, and resistance to aggressive media. Such joints are applied in the construction of chemical tankers, apparatus and chemical plants and power steam stations. Using the proper binder makes possible the welds directly between the elements of austenitic stainless steels and duplex ones. It causes that such joits behave satisfactorily in service in such areas like maritime constructions and steam and chemical plants. These steels have high mechanical properties such as: the yield strength, the tensile strength and the ductility as well as the resistance to general corrosion media. They are resistant to both pitting and stress corrosions. The relatively low cost of production of duplex steels, in comparison with standard austenitic steels, is inter alia, the result of a reduced amount of scarce and expensive Nickel, which is seen as a further advantage of these steels.

  11. Performance Steel Castings

    DTIC Science & Technology

    2012-09-30

    alloys , foundry, muzzle brake, supply center, tooling, sources Notice Distribution Statement A Format Information Report created in Microsoft Word...Development of Sand Properties 103 Advanced Modeling Dataset.. 105 High Strength Low Alloy (HSLA) Steels 107 Steel Casting and Engineering Support...University, University of Northern Iowa, Non- Ferrous Founders’ Society, QuesTek, buyCASTINGS.com, Spokane Industries, Nova Precision Casting, Waukesha

  12. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  13. Joining Steel Armor - Intermix

    DTIC Science & Technology

    1979-03-01

    TARADCOM a d ki Lk A el B~ 0el RWET0 TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX March 1979 U U * S* ’ "U .by B. . A.SCEV * U...authorized documents. O "if TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX BY B. A. SCHEVO March 1979 AMS: 3197..6D.4329 TARADCOM ARMOR AND...Intermix Process ...... ........ 3 Test Procedures - Intermix Armor ........ ......... 4 Mock Hull ................. ..................... 5 Results

  14. Ferrium M54 Steel

    DTIC Science & Technology

    2015-03-18

    release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Bare and Zn-14% Ni alloy coated Ferrium M54 steels were studied to...Ni alloy coating appears to provide the steel some protection against hydrogen embrittlement/SCC and corrosion fatigue in aqueous 3.5% NaCl...301-342-8069 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18 NAWCADPAX/TIM-2014/292 ii SUMMARY Bare and Zn-14% Ni alloy

  15. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  16. Correlation Between Shear Punch and Tensile Strength for Low-Carbon Steel and Stainless Steel Sheets

    NASA Astrophysics Data System (ADS)

    Mahmudi, R.; Sadeghi, M.

    2013-02-01

    The deformation behavior of AISI 1015 low-carbon steel, and AISI 304 stainless steel sheets was investigated by uniaxial tension and the shear punch test (SPT). Both materials were cold rolled to an 80% thickness reduction and subsequently annealed in the temperature range 25-850 °C to produce a wide range of yield and ultimate strength levels. The correlations between shear punch and tensile yield and ultimate stresses were established empirically. Different linear relationships having different slopes and intercepts were found for the low-carbon and stainless steel sheets, and the possible parameters affecting the correlation were discussed. It was shown that, within limits, yield and tensile strength of thin steel sheets can be predicted from the shear data obtained by the easy-to-perform SPT.

  17. Articles comprising ferritic stainless steels

    SciTech Connect

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  18. Waste product profile: Steel cans

    SciTech Connect

    Miller, C.

    1996-07-01

    Steel cans are made from tinplate steel, which is produced in basic oxygen furnaces. A thin layer of tin is applied to the can`s inner and outer surfaces to prevent rusting and protect food and beverage flavors. As a result, steel cans are often called tin cans. Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. Continued decreases in the amount of tin used in steel cans has lessened the importance of this market. Foundries use scrap as a raw material in making castings and molds for industrial users.

  19. Castings, Steel, Homogenization of Steel Castings

    DTIC Science & Technology

    1942-12-05

    diffraction pattern of quenched and tempered steel castings. 2. Calculations based upon known diffusion rates show: A. Practical homogenizing heat ...will be largely eliminated by either the usual heating for nuenching or a homo- genizing treatment. C. Interdendritic segregation of sulfur will...26 Appendix A - History of the Heat Treatment and Composition of Centrifugal Gun Castings at W-tertown Ar- sen-.l. ..... ..................... 2

  20. Characterization of friction stir welded joint of low nickel austenitic stainless steel and modified ferritic stainless steel

    NASA Astrophysics Data System (ADS)

    Mondal, Mounarik; Das, Hrishikesh; Ahn, Eun Yeong; Hong, Sung Tae; Kim, Moon-Jo; Han, Heung Nam; Pal, Tapan Kumar

    2017-09-01

    Friction stir welding (FSW) of dissimilar stainless steels, low nickel austenitic stainless steel and 409M ferritic stainless steel, is experimentally investigated. Process responses during FSW and the microstructures of the resultant dissimilar joints are evaluated. Material flow in the stir zone is investigated in detail by elemental mapping. Elemental mapping of the dissimilar joints clearly indicates that the material flow pattern during FSW depends on the process parameter combination. Dynamic recrystallization and recovery are also observed in the dissimilar joints. Among the two different stainless steels selected in the present study, the ferritic stainless steels shows more severe dynamic recrystallization, resulting in a very fine microstructure, probably due to the higher stacking fault energy.

  1. Neutron Irradiation Resistance of RAFM Steels

    SciTech Connect

    Gaganidze, Ermile; Dafferner, Bernhard; Aktaa, Jarir

    2008-07-01

    The neutron irradiation resistance of the reduced-activation ferritic/martensitic (RAFM) steel EUROFER97 and international reference steels (F82H-mod, OPTIFER-Ia, GA3X and MANET-I) have been investigated after irradiation in the Petten High Flux Reactor up to 16.3 dpa at different irradiation temperatures (250-450 deg. C). The embrittlement behavior and hardening are investigated by instrumented Charpy-V tests with sub-size specimens. Neutron irradiation-induced embrittlement and hardening of EUROFER97 was studied under different heat treatment conditions. Embrittlement and hardening of as-delivered EUROFER97 steel are comparable to those of reference steels. Heat treatment of EUROFER97 at a higher austenitizing temperature substantially improves the embrittlement behaviour at low irradiation temperatures. Analysis of embrittlement vs. hardening behavior of RAFM steels within a proper model in terms of the parameter C={delta}DBTT/{delta}{sigma} indicates hardening-dominated embrittlement at irradiation temperatures below 350 deg. C with 0.17 {<=} C {<=} 0.53 deg. C/MPa. Scattering of C at irradiation temperatures above 400 deg. C indicates non hardening embrittlement. A role of He in a process of embrittlement is investigated in EUROFER97 based steels, that are doped with different contents of natural B and the separated {sup 10}B-isotope (0.008-0.112 wt.%). Testing on small scale fracture mechanical specimens for determination of quasi-static fracture toughness will be also presented in a view of future irradiation campaigns. (authors)

  2. Profiles in garbage: Steel cans

    SciTech Connect

    Miller, C.

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  3. Laser beam welding of new ultra-high strength and supra-ductile steels

    NASA Astrophysics Data System (ADS)

    Dahmen, Martin

    2015-03-01

    Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

  4. Influence of carbon steel grade on the initial attachment of bacteria and microbiologically influenced corrosion.

    PubMed

    Javed, M A; Neil, W C; Stoddart, P R; Wade, S A

    2016-01-01

    The influence of the composition and microstructure of different carbon steel grades on the initial attachment (≤ 60 min) of Escherichia coli and subsequent longer term (28 days) corrosion was investigated. The initial bacterial attachment increased with time on all grades of carbon steel. However, the rate and magnitude of bacterial attachment varied on the different steel grades and was significantly less on the steels with a higher pearlite phase content. The observed variations in the number of bacterial cells attached across different steel grades were significantly reduced by applying a fixed potential to the steel samples. Longer term immersion studies showed similar levels of biofilm formation on the surface of the different grades of carbon steel. The measured corrosion rates were significantly higher in biotic conditions compared to abiotic conditions and were found to be positively correlated with the pearlite phase content of the different grades of carbon steel coupons.

  5. Notch-Fatigue Properties of Advanced TRIP-Aided Bainitic Ferrite Steels

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Nobuo; Kobayashi, Junya; Sugimoto, Koh-ichi

    2012-11-01

    To develop a transformation-induced plasticity (TRIP)-aided bainitic ferrite steel (TBF steel) with high hardenability for a common rail of the next generation diesel engine, 0.2 pct C-1.5 pct Si-1.5 pct Mn-0.05 pct Nb TBF steels with different contents of Cr, Mo, and Ni were produced. The notch-fatigue strength of the TBF steels was investigated and was related to the microstructural and retained austenite characteristics. If Cr, Mo, and/or Ni were added to the base steel, then the steels achieved extremely higher notch-fatigue limits and lower notch sensitivity than base TBF steel and the conventional structural steels. This was mainly associated with (1) carbide-free and fine bainitic ferrite lath structure matrix without proeutectoid ferrite, (2) a large amount of fine metastable retained austenite, and (3) blocky martensite phase including retained austenite, which may suppress a fatigue crack initiation and propagation.

  6. Hole expansion of dual phase steels

    SciTech Connect

    Xu, Le; Barlat, Frederic; Lee, M.G.; Choi, Kyoo Sil; Sun, Xin

    2012-06-01

    In this work, the stretch-flangeability of dual phase (DP) steels was investigated through the hole expansion (HE) tests for three DP980 steel sheet samples. In order to understand the effect of hole surface quality on the HE results, the specimens were prepared with three hole machining methods, namely, electrical discharge machining (EDM), punching and laser cutting. The HE results were discussed in terms of the hole surface quality before and after testing. Moreover, the failure behaviour was analyzed based on the observations of the fracture surfaces using optical microscopy (OM) and scanning electron microscopy (SEM).

  7. Economic feasibility of radioactive scrap steel recycling

    SciTech Connect

    Balhiser, R.; Rosholt, D.; Nichols, F.

    1995-12-31

    The goal of MSE`s Radioactive Scrap Steel (RSS) Recycle Program is to develop practical methods for recycling RSS into useful product. This paper provides interim information about ongoing feasibility investigations that are scheduled for completion by September 1995. The project approach, major issues, and cost projections are outlined. Current information indicates that a cost effective RSS Recycling Facility can be designed, built, and in operation by 1999. The RSS team believes that high quality steel plate can be made from RSS at a conversion cost of $1500 per ton or less.

  8. Developments in the continuous galvanizing of steel

    NASA Astrophysics Data System (ADS)

    Bush, Glenn W.

    1989-08-01

    The performance history of galvanized steels, particularly in the automotive industry, has heightened demand for both hot-dip galvanized and electrogalvanized products. Such marketability has led to the commissioning of several new galvanizing lines in recent years. Still, for this timehonored coating process to remain competitive, researchers are investigating methods to improve surface appearance, coating uniformity, corrosion resistance and cost effectiveness.

  9. View northwest, wharf A, sheet steel bulkhead, steel lift tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northwest, wharf A, sheet steel bulkhead, steel lift tower - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

  10. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... Brazil and Japan, and the suspended investigation on hot-rolled steel from Russia. SUMMARY: The... Japan, and the suspended investigation on hot-rolled steel from Russia would be likely to lead to...

  11. 76 FR 47150 - Galvanized Steel Wire From the People's Republic of China and Mexico: Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... International Trade Administration Galvanized Steel Wire From the People's Republic of China and Mexico... duty investigations of galvanized steel wire from the People's Republic of China (PRC) and Mexico. The... Steel Wire From the People's Republic of China and Mexico: Initiation of Antidumping Duty Investigations...

  12. Dislocation substructure in fatigued duplex stainless steel

    SciTech Connect

    Polak, J. . Lab. de Mecanique de Lille Inst. of Physical Metallurgy, Brno . Academy of Sciences); Degallaix, S. . Lab. de Mecanique de Lille); Kruml, T. . Academy of Sciences)

    1993-12-15

    Cyclic plastic straining of crystalline materials results in the formation of specific dislocation structures. Considerable progress in mapping and understanding internal dislocation structures has been achieved by studying single crystal behavior: however, most structural materials have a polycrystalline structure and investigations of polycrystals in comparison to single crystal behavior of simple metals prove to be very useful in understanding more complex materials. There are some classes of materials, however, with complicated structure which do not have a direct equivalent in single crystalline form. Moreover, the specific dimensions and shapes of individual crystallites play an important role both in the cyclic stress-strain response of these materials and in the formation of their interior structure in cyclic straining. Austenitic-ferritic duplex stainless steel, which is a kind of a natural composite, is a material of this type. The widespread interest in the application of duplex steels is caused by approximately doubled mechanical properties and equal corrosion properties, when compared with classical austenitic stainless steels. Fatigue resistance of these steels as well as the surface damage evolution in cyclic straining have been studied; however, much less is known about the internal substructure development in cyclic straining. In this study the dislocation arrangement in ferritic and austenitic grains of the austenitic-ferritic duplex steel alloyed with nitrogen and cyclically strained with two strain amplitudes, is reported and compared to the dislocation arrangement found in single and polycrystals of austenitic and ferritic materials of a similar composition and with the surface relief produced in cyclic plastic straining.

  13. Aging degradation of cast stainless steel

    SciTech Connect

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450/sup 0/C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the ..cap alpha..' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450/sup 0/C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450/sup 0/C. 18 refs., 13 figs.

  14. Electron Microscopy Study of Stainless Steel Radiation Damage Due to Long-Term Irradation by Alpha Particles Emitted From Plutonium

    SciTech Connect

    Unlu, Kenan; Rios-Martinez, Carlos; Saglam, Mehmet; Hart, Ron R.; Shipp, John D.; Rennie, John

    1998-04-16

    Radiation damage and associated surface and microstructural changes produced in stainless steel encapsulation by high-fluence alpha particle irradiations from weapons-grade plutonium of 316-stainless steel are being investigated.

  15. Investigation of the Microstructure Evolution in a Fe-17Mn-1.5Al-0.3C Steel via In Situ Synchrotron X-ray Diffraction during a Tensile Test.

    PubMed

    Ma, Yan; Song, Wenwen; Bleck, Wolfgang

    2017-09-25

    The quantitative characterization of the microstructure evolution in high-Mn steel during deformation is of great importance to understanding its strain-hardening behavior. In the current study, in situ high-energy synchrotron X-ray diffraction was employed to characterize the microstructure evolution in a Fe-17Mn-1.5Al-0.3C steel during a tensile test. The microstructure at different engineering strain levels-in terms of ε-martensite and α'-martensite volume fractions, the stacking fault probability, and the twin fault probability-was analyzed by the Rietveld refinement method. The Fe-17Mn-1.5Al-0.3C steel exhibits a high ultimate tensile strength with a superior uniform elongation and a high strain-hardening rate. The remaining high strain-hardening rate at the strain level about 0.025 to 0.35 results from ε-martensite dominant transformation-induced-plasticity (TRIP) effect. The increase in the strain-hardening rate at the strain level around 0.35 to 0.43 is attributed to the synergetic α'-martensite dominant TRIP and twinning-induced-plasticity (TWIP) effects. An evaluation of the stacking fault energy (SFE) of the Fe-17Mn-1.5Al-0.3C steel by the synchrotron measurements shows good agreement with the thermodynamic calculation of the SFE.

  16. In situ investigation of the effect of hydrogen on the plastic deformation ahead of the crack tip and the crack propagation of 0.15C-1.5Mn-0.17V-0.012N steel

    SciTech Connect

    Liao, B.; Nan, Y.; Hu, Y.; Kang, D.T.

    1998-02-01

    The influence of hydrogen on the deformation ahead of the crack tip and the crack propagation were observed and studied in situ under transmission electron microscopy with dynamic tensile deformation for steel. The results show that hydrogen can promote local plastic deformation ahead of the crack tip and change the mode of crack propagation so that the crack will propagate in a zigzag path.

  17. Application of EIS and SECM Studies for Investigation of Anticorrosion Properties of Epoxy Coatings Containing Zinc Oxide Nanoparticles on Mild Steel in 3.5% NaCl Solution

    NASA Astrophysics Data System (ADS)

    Raj, X. Joseph

    2017-07-01

    The effect of corrosion protection performance of epoxy coatings containing ZnO nanoparticle on mild steel in 3.5% NaCl solution was analyzed using scanning electrochemical microscopy and electrochemical impedance spectroscopy (EIS). Line profile and topographic image analysis were measured by applying -0.70 and +0.60 V as the tip potential for the cathodic and anodic reactions, respectively. The tip current at -0.70 V for the epoxy-coated sample with ZnO nanoparticles decreased rapidly, which is due to cathodic reduction in dissolved oxygen. The EIS measurements were taken in 3.5% NaCl after wet and dry cyclic corrosion test. The increase in the film resistance ( R f) and charge transfer resistance ( R ct) values was confirmed by the addition of ZnO nanoparticles in the epoxy coating. SEM/EDX analysis showed that complex oxide layer of zinc was enriched in corrosion products at a scratched area of the coated steel after corrosion testing. FIB-TEM analysis confirmed the presence of the nanoscale complex oxide layer of Zn in the rust of the steel that had a beneficial effect on the corrosion resistance of coated steel by forming protective corrosion products in the wet/dry cyclic test.

  18. Physical metallurgy of direct-quenched steels

    SciTech Connect

    Taylor, K.A. ); Thompson, S.W. ); Fletcher, F.B. )

    1993-01-01

    This symposium was held during November 2-4, 1992 in Chicago as part of Materials Week '92''. This symposium focused on the metallurgy of steels containing martensitic or bainitic microstructures formed from thermomechanically processed austenite, and builds upon two recent topical meetings on the related subject of ferritic accelerated cooled steels. Papers in the first section deal with thermodynamics and kinetics of austenite transformation, the morphology of austenite transformation products, and alloy carbide precipitation. Results of investigations of relationships between processing variables, microstructure, and mechanical properties are contained in the following section. Section III is devoted specifically to boron hardenability effects. papers in the final section are concerned with product development; included here is a comprehensive overview of industrial accelerated cooling/direct quenching technology by researchers from the Nippon Steel Corporation.

  19. Superclean steel development

    SciTech Connect

    Richman, R.H.; McNaughton, W.P. )

    1989-12-01

    The Electric Power Research Institute has actively encouraged and sponsored a number of research projects to develop a superclean 3.5NiCrMoV steel for low pressure turbine rotors. Such steel is highly resistant to temper embrittlement and will thus facilitate increased efficiency in electricity generation through the use of higher operating temperatures and improvements in design. The objective of this interim report was to integrate the results that have been generated to date worldwide in the pursuit of superclean steel. The report contains detailed findings that enable the interested utility to evaluate how the results affect utility decision making. A companion document has been written to summarize the findings from this technical report. The results indicate that steels with impurity contents typical of the superclean specification can be manufactured for production rotors with properties that equal or exceed those for conventional 3.5NiCrMoV rotors in every detail. Of particular interest are the results that the superclean steels appear to be virtually resistant to temper embrittlement to a temperature of 500 {degrees}C. 109 refs., 51 figs., 9 tabs.

  20. [Factors influencing electrocardiogram results in workers exposed to noise in steel-making and steel-rolling workshops of an iron and steel plant].

    PubMed

    Li, Y H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Jiao, J

    2016-02-20

    To investigate the factors influencing the electrocardiogram results in the workers exposed to noise in steel-making and steel rolling workshops of an iron and steel plant. From September to December, 2013, cluster sampling was used to select 3 150 workers exposed to noise in the steel-making and steel-rolling workshops of an iron and steel plant, and a questionnaire survey and physical examinations were performed. The number of valid workers was 2 915, consisting of 1 606 workers in the steel-rolling workshop and 1 309 in the steel-making workshop. The electrocardiogram results of the workers in steel-making and steel-rolling workshops were analyzed. The overall abnormal rate of electrocardiogram was 26.35%, and the workers in the steel-making workshop had a significantly higher abnormal rate of electrocardiogram than those in the steel-rolling workshop(32.24% vs 21.54%, P<0.05). Male workers had a significantly higher abnormal rate of electrocardiogram than female workers(27.59% vs 18.61%, P<0.05). The workers with a drinking habit had a significantly higher abnormal rate of electrocardiogram than those who did not drink(28.17% vs 23.75%, P<0.05). The workers exposed to high temperature had a significantly higher abnormal rate of electrocardiogram than those who were not exposed to high temperature(29.43% vs 20.14%, P<0.05). The abnormal rates of electrocardiogram in the workers with cumulative noise exposure levels of <90, 90~94, 95~99, 100~104, and 105~113 dB(A)·year were 21.21%, 21.76%, 26.50%, 27.27%, and 32.16%, respectively, with significant differences between any two groups(P<0.05). The multivariate logistic regression analysis showed that a cumulative noise exposure of 105-113 dB(A)·year(OR=1.36, 95% CI: 1.03~1.80), a drinking habit(OR=1.20, 95% CI: 1.01~1.43), and high temperature(OR=1.60, 95% CI: 1.32~1.92) were the risk factors for abnormal electrocardiogram results. High cumulative noise exposure, alcohol consumption, and high temperature may

  1. Trends in steel technology. [Dual phase and HSLA steels

    SciTech Connect

    Not Available

    1980-01-01

    Dual phase steels, composite products, and microalloyed steels are making inroads in the automotive industry applications for bumpers, automotive parts, bodies, mechanical parts, suspension and steering equipment and truck bumpers. New steels are also used to support solar mirrors and cells, in corrosive environments in the oil and gas industry, fusion reactors, and pressure vessels in nuclear power plants. (FS)

  2. Spot welding of steel and aluminum using insert sheet

    SciTech Connect

    Oikawa, H.; Saito, T.; Yoshimura, T.

    1994-12-31

    Automobile industries have been increasingly interested in the use of aluminum and thus joining of steel and aluminum becomes of importance. The joining of the two types of metal raises a problem of brittle welds caused by the formation of intermetallic compounds. The authors solved the problem by using an insert sheet. This paper deals with the resistance spot welding of steel and aluminum sheets using insert sheets. The insert sheet used in the present development was a steel/aluminum clad sheet of the 0.8 mm thickness with 50% steel and 50% aluminum. The clad sheet was produced by warm rolling of steel and aluminum with a direct resistance heating process. Steel to be warm rolled was of EDDQ of the 0.4 mm thickness and aluminum was of JIS A1050 of 0.6 mm thickness. The mechanical properties of the insert clad sheets were in between those of the steel sheets and the aluminum sheets, while the clad sheets showed much better formability than the aluminum sheets. Resistance spot welding was conducted for 0.8 mm thick EDDQ steel sheets and 1.0 mm thick aluminum alloy (AL-5.5%Mg) sheets under the welding force of 1.96 kN, welding current ranging between 4.2 and 20.1 kA, and welding time from 0.5 to 10 cycles. The steel was spot welded to the steel side of the insert sheet while the aluminum was welded to the aluminum side. What the authors investigated were the applicable welding current range, nugget diameter, tensile shear strength, U-tension strength, and macro- and microstructures. In conclusion, steel sheets can be spot welded to aluminum sheets without difficulty by using clad sheets as insert materials while the strength level of the dissimilar metal spot welds is close to that of aluminum joints.

  3. 76 FR 21914 - Galvanized Steel Wire From China and Mexico

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject antidumping and countervailing duty investigations....

  4. 75 FR 8113 - Prestressed Concrete Steel Wire Strand From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Prestressed Concrete Steel Wire Strand From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject investigations. DATES: Effective Date: February 16,...

  5. Continuous steel production and apparatus

    DOEpatents

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  6. Brazing titanium to stainless steel

    NASA Technical Reports Server (NTRS)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  7. Transient liquid-phase bonding of ODS steels

    NASA Astrophysics Data System (ADS)

    Noto, H.; Ukai, S.; Hayashi, S.

    2011-10-01

    The use of transient liquid-phase bonding of 9CrODS steels using Fe-3B-2Si-0.5C filler was investigated for bonding temperature of 1180 °C and hold times of 0.5-4.0 h. The sequential process, consisting of isothermal melting, solidification and homogenization, was confirmed for bonding the 9CrODS steel. The precipitation of chromium boride found in 19CrODS steel is avoided in 9CrODS steel due to the lower Cr content. Silicon tends to be slightly enriched inside the bonding zone. Agglomeration and coarsening of Y 2O 3 particles in 9CrODS steel lead to softening inside the bonding zone formed by incipient melting of the foil bonding alloy, and in a diffusion affected zone (DAZ) adjacent to the bonding zone.

  8. High Cycle Fatigue Behavior of Shot-Peened Steels

    NASA Astrophysics Data System (ADS)

    Mirzazadeh, M. M.; Plumtree, A.

    2012-08-01

    The uniaxial fully reversed (R = -1) long life fatigue behavior of four shot-peened engineering steels with approximately the same hardness was investigated. Shot-peening, air-cooled forged AISI 1141 and crackable AISI 1070 steels had little effect on their fatigue limits (+2.5 and -2.0 pct, respectively). In the case of a powder forged 0.5 pct C steel, an increase in the fatigue limit of 10.4 pct was observed, albeit with a large standard deviation. Shot-peening quench and tempered AISI 1151 steel decreased its fatigue limit 12.0 pct, as a result of cyclic softening. In general, the beneficial effects of shot-peening these smooth specimens were relatively small. Neither cyclic softening nor hardening occurred in the non-shot-peened steels cycled under the same conditions.

  9. Tensile properties of the modified 13Cr martensitic stainless steels

    NASA Astrophysics Data System (ADS)

    Mabruri, Efendi; Anwar, Moch. Syaiful; Prifiharni, Siska; Romijarso, Toni B.; Adjiantoro, Bintang

    2016-04-01

    This paper reports the influence of Mo and Ni on the tensile properties of the modified 13Cr martensitic stainless steels in tempered condition. Four steels with different content of Mo and Ni were prepared by induction melting followed by hot forging, quenching and tempering. The experimental results showed that the addition of about 1% and 3% Mo has a beneficial effect to increase both the tensile strength and the elongation of the steels. On the contrary, the addition of about 3% Ni into the martensitic stainless steel results in decreasing of both the tensile strength and the elongation. Among the alloys investigated the 13Cr3Mo type steel exhibited largest tensile strength of 1348 MPa and largest elongation of 12%. The observation on the tensile fractured surfaces by using scanning electron microscope supported these findings.

  10. An internal friction peak caused by hydrogen in maraging steel

    SciTech Connect

    Usui, Makoto; Asano, Shigeru

    1996-01-01

    Internal friction in hydrogen-charged iron and steel has so far been studied by a large number of investigators. For pure iron, a well-defined peak of internal friction has been observed under the cold-worked and hydrogen-charged conditions. This is called the hydrogen cold-work peak, or the Snoek-Koester relaxation, which originates from the hydrogen-dislocation interaction. In the present study, a high-strength maraging steel (Fe-18Ni-9Co-5Mo) was chosen as another high-alloy steel which is known to be very susceptible to hydrogen embrittlement. The purpose of this paper is to show a new internal friction peak caused by hydrogen in the maraging steel and to compare it with those found in stainless steels which have so far been studied as typical engineering high-alloy materials.

  11. Production of Green Steel from Red Mud: A Novel Concept

    NASA Astrophysics Data System (ADS)

    Bhoi, Bhagyadhar; Behera, Pravas Ranjan; Mishra, Chitta Ranjan

    Red mud of Indian origin contains around 55% plus of Fe2O3 and is considered as a hazardous waste for the alumina industry. For production of one tone of alumina employing the Bayer's Process, around two tones of red mud is generated from three tones of Bauxite. Conventional process of steel making is not devoid of environmental pollution. In the present investigation, efforts have been made to produce steel from red mud by adopting reduction roasting, magnetic separation and hydrogen plasma smelting route. Magnetic fraction, containing enriched iron oxide and minimal content of alumina, is produced following the first two stages which is then subjected to hydrogen plasma smelting process for production of steel. This novel concept follows a green path way for production of steel free from pollution and is termed as green steel. Further, the only by-product that is produced in the process, is water, which is eco-friendly and recyclable.

  12. Tensile properties of the modified 13Cr martensitic stainless steels

    SciTech Connect

    Mabruri, Efendi Anwar, Moch Syaiful Prifiharni, Siska Romijarso, Toni B.; Adjiantoro, Bintang

    2016-04-19

    This paper reports the influence of Mo and Ni on the tensile properties of the modified 13Cr martensitic stainless steels in tempered condition. Four steels with different content of Mo and Ni were prepared by induction melting followed by hot forging, quenching and tempering. The experimental results showed that the addition of about 1% and 3% Mo has a beneficial effect to increase both the tensile strength and the elongation of the steels. On the contrary, the addition of about 3% Ni into the martensitic stainless steel results in decreasing of both the tensile strength and the elongation. Among the alloys investigated the 13Cr3Mo type steel exhibited largest tensile strength of 1348 MPa and largest elongation of 12%. The observation on the tensile fractured surfaces by using scanning electron microscope supported these findings.

  13. Chromizing of 3Cr Steel

    SciTech Connect

    Ravi, Vilupanur; Harrison, Bradley; Koch, Jordan; Ly, Alexander; Schissler, Andrew; Pint, Bruce A; Haynes, James A

    2011-01-01

    Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N) was chromized by the halide-activated pack cementation (HAPC) process. Key process parameters, i.e., coating temperatures and pack compositions, were investigated. Ammonium chloride-activated packs in the 700-1000 C range produced coatings nominally in the 1-8 {micro}m range, as determined by optical and scanning electron microscopy (SEM). Coatings applied in the 900-1000 C temperature range resulted in Cr-rich coatings. The predominant phase in the coating was identified as Cr23C6 by X-ray diffraction. In addition, the presence of chromium nitride, Cr2N, was observed in the coating. The power generation industry is faced with an ever-increasing demand for energy while simultaneously having to reduce carbon emissions. These goals can be facilitated by increasing plant efficiency through the use of higher operating temperatures and pressures. Traditional construction materials, e.g., the ferritic Grade 22 high strength low alloy steel, are limited to operations below {approx} 550 C. Therefore, new materials are required for future plants designed to operate up to 650 C and possibly higher. These new materials need to have improved tensile strength, ductility, toughness, corrosion resistance, and creep properties at elevated temperatures. Oak Ridge National Laboratory (ORNL) is investigating the oxidation and creep behavior of various coatings on Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N), a super-bainitic steel developed for superior creep properties. Thin, chemical vapor-deposited (CVD) aluminide coatings were used to compensate for the reduced corrosion and oxidation resistance that resulted from the low chromium content of the alloy. However, the aluminized Grade 315 alloys performed less-than-favorably under conditions relevant to fossil boilers, leading to the conclusion that higher chromium contents are required for the formation of

  14. Stainless steel tanks

    SciTech Connect

    Hagen, T.

    1995-12-31

    There is currently no recognized code or standard for the design, fabrication and construction of atmospheric and low pressure stainless steel tanks. At the present time these tanks are being designed to individual specifications, manufacturers standards or utilizing other codes and standards that may not be entirely applicable. Recognizing the need, the American Petroleum Institute will be publishing a new appendix to the API STD 650 Standard which will cover stainless steel tanks. The new Appendix was put together by a Task Group of selected individuals from the API Subcommittee of Pressure Vessels and Tanks from the Committee on Refinery Equipment. This paper deals with the development and basis of the new appendix. The new appendix will provide a much needed standard to cover the material, design, fabrication, erection and testing requirements for vertical, cylindrical, austenitic stainless steel aboveground tanks in nonrefrigerated service.

  15. Effect of grain refinement on mechanical properties of martensitic steel

    NASA Astrophysics Data System (ADS)

    Islamgaliev, R. K.; Nikitina, M. A.; Ganeev, A. V.; Karavaeva, M. V.

    2017-05-01

    Microstructure and strength of commercial martensitic steel processed by equal channel angular pressing (ECAP) has been investigated using transmission electron microscopy and tensile tests. Application of ECAP led to significant grain refinement to a grain size of 0.8 µm and precipitation of particles with a size of 90 nm. Impact of annealing on thermal stability of ultrafine-grained structure was investigated. The contribution of various strengthening mechanisms to strength of steel was discussed.

  16. Mechanical behavior study of laser welded joints for DP steel

    NASA Astrophysics Data System (ADS)

    Yan, Qi

    2008-03-01

    Advanced High Strength Steels (AHSS) are gaining considerable market shares in the automotive industry. The development and application of Dual Phase (DP) steel is just a consistent step towards high-strength steel grades with improved mechanical behavior. Tailor welded blanks with DP steel are promoted in the application of Body-In-White (BIW) structure by the automotive industry. A tailor welded blank consists of several flat sheets that are laser welded together before stamping. Applied cases of tailor welded blanks of high strength steels on the automotive structural parts are investigated in this paper. The mechanical behavior of laser welded joints for DP steel is studied. Microstructure of laser welded joints for DP steel was observed by SEM. Martensite in the weld seam explains the higher strength of welded joints than the base metal. Results show that the strain safety tolerance of laser welded seam for high strength steel can meet the requirement of automobile parts for stamping if the location of laser welded seam is designed reasonably.

  17. Nickel release from nickel-plated metals and stainless steels.

    PubMed

    Haudrechy, P; Foussereau, J; Mantout, B; Baroux, B

    1994-10-01

    Nickel release from nickel-plated metals often induces allergic contact dermatitis, but, for nickel-containing stainless steels, the effect is not well-known. In this paper, AISI 304, 316L, 303 and 430 type stainless steels, nickel and nickel-plated materials were investigated. 4 tests were performed: patch tests, leaching experiments, dimethylglyoxime (DMG) spot tests and electrochemical tests. Patch tests showed that 96% of the patients were intolerant to Ni-plated samples, and 14% to a high-sulfur stainless steel (303), while nickel-containing stainless steels with a low sulfur content elicited no reactions. Leaching experiments confirmed the patch tests: in acidic artificial sweat, Ni-plated samples released about 100 micrograms/cm2/week of nickel, while low-sulfur stainless steels released less than 0.03 microgram/cm2/week of nickel, and AISI 303 about 1.5 micrograms/cm2/week. Attention is drawn to the irrelevance of the DMG spot test, which reveals Ni present in the metal bulk but not its dissolution rate. Electrochemical experiments showed that 304 and 316 grades remain passive in the environments tested, while Ni-plated steels and AISI 303 can suffer significant cation dissolution. Thus, Ni-containing 304 and 316 steels should not induce contact dermatitis, while 303 should be avoided. A reliable nitric acid spot test is proposed to distinguish this grade from other stainless steels.

  18. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  19. A-3 steel work completed

    NASA Image and Video Library

    2009-04-09

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  20. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  1. Thermally Stable Nanocrystalline Steel

    NASA Astrophysics Data System (ADS)

    Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

    2017-10-01

    Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

  2. Active wear and failure mechanisms of TiN-coated high speed steel and TiN-coated cemented carbide tools when machining powder metallurgically made stainless steels

    SciTech Connect

    Jiang, L.; Haenninen, H.; Paro, J.; Kauppinen, V.

    1996-09-01

    In this study, active wear and failure mechanisms of both TiN-coated high speed steel and TiN-coated cemented carbide tools when machining stainless steels made by powder metallurgy in low and high cutting speed ranges, respectively, have been investigated. Abrasive wear mechanisms, fatigue-induced failure, and adhesive and diffusion wear mechanisms mainly affected the tool life of TiN-coated high speed steel tools at cutting speeds below 35 m/min, between 35 and 45 m/min, and over 45 m/min, respectively. Additionally, fatigue-induced failure was active at cutting speeds over 45 m/min in the low cutting speed range when machining powder metallurgically made duplex stainless steel 2205 and austenitic stainless steel 316L. In the high cutting speed range, from 100 to 250 m/min, fatigue-induced failure together with diffusion wear mechanism, affected the tool life of TiN-coated cemented carbide tools when machining both 316L and 2205 stainless steels. It was noticed that the tool life of TiN-coated high speed steel tools used in the low cutting speed range when machining 2205 steel was longer than that when machining 316L steel, whereas the tool life of TiN-coated cemented carbide tools used in the high cutting speed range when machining 316L steel was longer than that when machining 2205 steel.

  3. Active wear and failure mechanisms of TiN-Coated high speed steel and tin-coated cemented carbide tools when machining powder metallurgically made stainless steels

    NASA Astrophysics Data System (ADS)

    Jiang, Laizhu; Hänninen, Hannu; Paro, Jukka; Kauppinen, Veijo

    1996-09-01

    In this study, active wear and failure mechanisms of both TiN-coated high speed steel and TiN-coated cemented carbide tools when machining stainless steels made by powder metallurgy in low and high cutting speed ranges, respectively, have been investigated. Abrasive wear mechanisms, fatigue-induced failure, and adhesive and diffusion wear mechanisms mainly affected the tool life of TiN-coated high speed steel tools at cutting speeds below 35 m/min, between 35 and 45 m/min, and over 45 m/min, respectively. Additionally, fatigue-induced failure was active at cutting speeds over 45 m/min in the low cutting speed range when machining powder metallurgically made duplex stainless steel 2205 and austenitic stainless steel 316L. In the high cutting speed range, from 100 to 250 m/min, fatigue-induced failure together with diffusion wear mechanism, affected the tool life of TiN-coated cemented carbide tools when machining both 316L and 2205 stainless steels. It was noticed that the tool life of TiN-coated high speed steel tools used in the low cutting speed range when machining 2205 steel was longer than that when machining 316L steel, whereas the tool life of TiN-coated cemented carbide tools used in the high cutting speed range when machining 316L steel was longer than that when machining 2205 steel.

  4. Effect of ultrafine grain on tensile behaviour and corrosion resistance of the duplex stainless steel.

    PubMed

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang; Limin, Dong

    2016-05-01

    The ultrafine grained 2205 duplex stainless steel was obtained by cold rolling and annealing. The tensile properties were investigated at room temperature. Comparing with coarse grained stainless steel, ultrafine grained sample showed higher strength and plasticity. In addition, grain size changed deformation orientation. The strain induced α'-martensite was observed in coarse grained 2205 duplex stainless steel with large strain. However, the grain refinement inhibited the transformation of α'-martensite;nevertheless, more deformation twins improved the strength and plasticity of ultrafine grained 2205 duplex stainless steel. In addition, the grain refinement improved corrosion resistance of the 2205 duplex stainless steel in sodium chloride solution.

  5. Effect of cerium on temper embrittlement of P-doped Mn structural steels

    SciTech Connect

    Zhexi, Yuan; Shenhua, Song; Faulkner, R.G.; Tingdong, Xu

    1994-01-01

    The effect of cerium on temper embrittlement of P-doped Mn structural steels has been investigated by measurements of the ductile-brittle transition temperature and observations by AES, SIMS and SEM of the fracture surfaces of isothermally embrittled steels. It is shown that P can bring about the temper embrittlement of Mn structural steels; cerium may reduce the temper embrittlement of the steels and the segregation of cerium to grain boundaries may play an important part in reducing the temper embrittlement of the steels.

  6. Braze alloy spreading on steel

    NASA Technical Reports Server (NTRS)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  7. Sensitization of stainless steel

    NASA Technical Reports Server (NTRS)

    Nagy, James P.

    1990-01-01

    The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

  8. Influence of original microstructure on the transformation behavior and mechanical properties of ultra-high-strength TRIP-aided steel

    NASA Astrophysics Data System (ADS)

    Yin, Hong-xiang; Zhao, Ai-min; Zhao, Zheng-zhi; Li, Xiao; Li, Shuang-jiao; Hu, Han-jiang; Xia, Wei-guang

    2015-03-01

    The transformation behavior and tensile properties of an ultra-high-strength transformation-induced plasticity (TRIP) steel (0.2C-2.0Si-1.8Mn) were investigated by different heat treatments for automobile applications. The results show that F-TRIP steel, a traditional TRIP steel containing as-cold-rolled ferrite and pearlite as the original microstructure, consists of equiaxed grains of intercritical ferrite surrounded by discrete particles of M/RA and B. In contrast, M-TRIP steel, a modified TRIP-aided steel with martensite as the original microstructure, containing full martensite as the original microstructure is comprised of lath-shaped grains of ferrite separated by lath-shaped martensite/retained austenite and bainite. Most of the austenite in F-TRIP steel is granular, while the austenite in M-TRIP steel is lath-shaped. The volume fraction of the retained austenite as well as its carbon content is lower in F-TRIP steel than in M-TRIP steel, and austenite grains in M-TRIP steel are much finer than those in F-TRIP steel. Therefore, M-TRIP steel was concluded to have a higher austenite stability, resulting in a lower transformation rate and consequently contributing to a higher elongation compared to F-TRIP steel. Work hardening behavior is also discussed for both types of steel.

  9. Increasing corrosion resistance of carbon steels by surface laser cladding

    NASA Astrophysics Data System (ADS)

    Polsky, V. I.; Yakushin, V. L.; Dzhumaev, P. S.; Petrovsky, V. N.; Safonov, D. V.

    2016-04-01

    This paper presents results of investigation of the microstructure, elemental composition and corrosion resistance of the samples of low-alloy steel widely used in the engineering, after the application of laser cladding. The level of corrosion damage and the corrosion mechanism of cladded steel samples were established. The corrosion rate and installed discharge observed at the total destruction of cladding were obtained. The regularities of structure formation in the application of different powder compositions were obtained. The optimal powder composition that prevents corrosion of samples of low-carbon low-alloy steel was established.

  10. 76 FR 33242 - Certain Steel Wheels From the People's Republic of China; Notice of Postponement of Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Certain Steel Wheels From the People's Republic of China; Notice of... investigation of certain steel wheels from the People's Republic of China. See Certain Steel Wheels From the...

  11. 78 FR 8107 - Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam: Countervailing Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... International Trade Administration Certain Steel Wire Garment Hangers From the Socialist Republic of Vietnam... order on certain steel wire garment hangers from the Socialist Republic of Vietnam (Vietnam). DATES... duty investigation of certain steel wire garment hangers from Vietnam.\\1\\ On January 28, 2013, the...

  12. 78 FR 50378 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan: Postponement of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ... International Trade Administration Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan... steel products from Japan. See Diffusion- Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan... Japan: Petitioner's Request for Extension of the Antidumping Investigation Preliminary Determination...

  13. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United...'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the suspended... antidumping duty orders on hot-rolled steel from Brazil and Japan, and the suspended investigation on hot...

  14. 78 FR 57619 - Prestressed Concrete Steel Rail Tie Wire From Mexico, Thailand, and the People's Republic of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From Mexico, Thailand, and the... antidumping duty investigations of imports of prestressed concrete steel rail tie wire from Mexico, Thailand, and the People's Republic of China. See Prestressed Concrete Steel Rail Tie Wire From Mexico,...

  15. 75 FR 47263 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian... carbon- quality steel products from the Russian Federation; final results. SUMMARY: On April 1, 2010, the... antidumping duty investigation of certain hot-rolled flat- rolled carbon-quality steel products (``hot-rolled...

  16. 75 FR 13255 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... International Trade Administration Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe... determination in this countervailing duty investigation of certain seamless carbon and alloy steel standard... of seamless pipe from the PRC. See Certain Seamless Carbon and Alloy Steel Standard, Line,...

  17. 75 FR 29972 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... International Trade Administration Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe... antidumping duty investigation of certain seamless carbon and alloy steel standard, line, and pressure pipe... in this proceeding. See Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure...

  18. 75 FR 6183 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... INTERNATIONAL TRADE ADMINISTRATION (A-570-956) Certain Seamless Carbon and Alloy Steel Standard, Line, and... investigation on certain seamless carbon and alloy steel standard, line, and pressure pipe from the People's Republic of China. See Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From...

  19. 77 FR 30589 - SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... Surface Transportation Board SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver Infrastructure Fund North America LP, and Patriot Funding LLC--Control Exemption--Patriot Rail Corp., et al. SteelRiver Infrastructure Partners LP (SRIP LP), SteelRiver...

  20. Effect of Stress Relief Annealing on Microstructure & Mechanical Properties of Welded Joints Between Low Alloy Carbon Steel and Stainless Steel

    NASA Astrophysics Data System (ADS)

    Nivas, R.; Das, G.; Das, S. K.; Mahato, B.; Kumar, S.; Sivaprasad, K.; Singh, P. K.; Ghosh, M.

    2017-01-01

    Two types of welded joints were prepared using low alloy carbon steel and austenitic stainless steel as base materials. In one variety, buttering material and weld metal were Inconel 82. In another type, buttering material and weld metal were Inconel 182. In case of Inconel 82, method of welding was GTAW. For Inconel 182, welding was done by SMAW technique. For one set of each joints after buttering, stress relief annealing was done at 923 K (650 °C) for 90 minutes before further joining with weld metal. Microstructural investigation and sub-size in situ tensile testing in scanning electron microscope were carried out for buttered-welded and buttered-stress relieved-welded specimens. Adjacent to fusion boundary, heat-affected zone of low alloy steel consisted of ferrite-pearlite phase combination. Immediately after fusion boundary in low alloy steel side, there was increase in matrix grain size. Same trend was observed in the region of austenitic stainless steel that was close to fusion boundary between weld metal-stainless steel. Close to interface between low alloy steel-buttering material, the region contained martensite, Type-I boundary and Type-II boundary. Peak hardness was obtained close to fusion boundary between low alloy steel and buttering material. In this respect, a minimum hardness was observed within buttering material. The peak hardness was shifted toward buttering material after stress relief annealing. During tensile testing no deformation occurred within low alloy steel and failure was completely through buttering material. Crack initiated near fusion boundary between low alloy steel-buttering material for welded specimens and the same shifted away from fusion boundary for stress relieved annealed specimens. This observation was at par with the characteristics of microhardness profile. In as welded condition, joints fabricated with Inconel 82 exhibited superior bond strength than the weld produced with Inconel 182. Stress relief annealing