Sample records for 17-7 ph stainless

  1. Cellular Precipitation at a 17-7 PH Stainless Steel Interphase Interface During Low-Temperature Nitridation

    NASA Astrophysics Data System (ADS)

    Wang, Danqi; Ernst, Frank; Kahn, Harold; Heuer, Arthur H.

    2014-07-01

    Cellular precipitation of Cr-rich nitrides was observed at an austenite-ferrite interface in 17-7 PH stainless steel after low-temperature nitridation. Fine-scale lamellar rocksalt-structured nitride (MN1- x , M: randomly distributed Fe, Cr, and Al) was identified at the interfaces between austenite and ferrite by local-electrode atom-probe tomography and transmission electron microscopy. The small size and spacing of the nitride lamellae reflect the low mobility of substitutional atoms under the conditions of low-temperature nitridation. Nitrides of the same structure were formed within the ferrite grain as extremely small particles. The face-centered cubic nitride precipitates in the Bain orientation relationship with the ferrite.

  2. Irradiation effects on 17-7 PH stainless steel, A-201 carbon steel, and titanium-6-percent-aluminum-4-percent-vanadium alloy

    NASA Technical Reports Server (NTRS)

    Hasse, R. A.; Hartley, C. B.

    1972-01-01

    Irradiation effects on three materials from the NASA Plum Brook Reactor Surveillance Program were determined. An increase of 105 K in the nil-ductility temperature for A-201 steel was observed at a fluence of approximately 3.1 x 10 to the 18th power neutrons/sq cm (neutron energy E sub n greater than 1.0 MeV). Only minor changes in the mechanical properties of 17-7 PH stainless steel were observed up to a fluence of 2 x 10 to the 21st power neutrons/sq cm (E sub n greater than 1.0 MeV). The titanium-6-percent-aluminum-4-percent-vanadium alloy maintained its notch toughness up to a fluence of 1 x 10 to the 21st power neutrons/sq cm (E sub n greater than 1.0 MeV).

  3. A scanning tunneling microscopy study of PH 3 adsorption on Si(1 1 1)-7 7 surfaces, P-segregation and thermal desorption

    NASA Astrophysics Data System (ADS)

    Ji, Jeong-Young; Shen, T.-C.

    2007-04-01

    PH 3 adsorption on Si(1 1 1)-7 7 was studied after various exposures between 0.3 and 60 L at room temperature by means of scanning tunneling microscopy (STM). PH 3-, PH 2-, H-reacted, and unreacted adatoms can be identified by analyzing empty-state STM images at different sample biases. PH x-reacted rest-atoms can be observed in empty-state STM images if neighboring adatoms are hydrogen terminated. Most of the PH 3 adsorbs dissociatively on the surface, generating H- and PH 2-adsorbed rest-atom and adatom sites. Dangling-bonds at rest-atom sites are more reactive than adatom sites and the faulted half of the 7 7 unit cell is more reactive than the unfaulted half. Center adatoms are overwhelmingly preferred over corner adatoms for PH 2 adsorption. The saturation P coverage is 0.18 ML. Annealing of PH 3-reacted 7 7 surfaces at 900 K generates disordered, partially P-covered surfaces, but dosing PH 3 at 900 K forms P/Si(1 1 1)- 6?{3} surfaces. Si deposition at 510 K leaves disordered clusters on the surface, which cannot be reordered by annealing up to 800 K. However, annealing above 900 K recreates P/Si(1 1 1)- 6?{3} surfaces. Surface morphologies formed by sequential rapid thermal annealing are also presented.

  4. High temperature tensile behavior of a PH stainless steel

    Microsoft Academic Search

    M. Aghaie-Khafri; A. Zargaran

    2010-01-01

    High temperature tensile deformation of 15-5 PH stainless steel in peak age and overaged conditions has been studied over the temperature range of 300 to 600C and different strain rates. Dynamic recrystallization was the main softening mechanism when the alloy deformed at imposed temperature and strain rate region. The apparent activation energy was calculated as 284.8 and 323.1kJ\\/mol for peak

  5. Hot deformation of 15-5 PH stainless steel

    Microsoft Academic Search

    M. Aghaie-Khafri; F. Adhami

    2010-01-01

    The hot deformation behavior of 15-5 PH stainless steel has been studied using hot compression tests over the temperature range of 9001150C and strain rates varying between 0.001 and 0.5s?1. The results showed that dynamic recrystallization is the main softening mechanism when the alloy deformed at imposed temperature and strain rate region. Strain rate sensitivity of the material was evaluated

  6. Production and aging of highly porous 17-4 PH stainless steel

    Microsoft Academic Search

    Ilven Mutlu; Enver Oktay

    This study describes production of highly porous 17-4 PH stainless steel for biomedical implant applications by space holder-sintering\\u000a technique. 17-4 PH stainless steel powders were mixed with space holder and then compacted. For designing pore properties,\\u000a both spherical and irregular shaped carbamide with different particle size ranges were used as space holder and removed by\\u000a water leaching. Porous 17-4 PH

  7. OBSERVATIONS ON CORROSION RESISTANCE OF HIGH STRENGTH STAINLESS STEELS FOR AIRCRAFT

    Microsoft Academic Search

    J. Halbig; O. B. Ellis

    1958-01-01

    Stainless steels of the precipitation hardening type are used ; extensively in airframe components. In this paper, compositions and properties ; of several of these alloys are described. The corrosion performances of the ; Armco 17-4 PH and 17-7 PH precipitation hardening alloys are compared with these ; of other hardenable stainless steels. The results of accelerated corrosion tests ;

  8. Weldability of 17-4 PH stainless steel in centrifugal compressor impeller applications

    Microsoft Academic Search

    J. Nowacki

    2004-01-01

    Weldability of 17-4 PH stainless steel for centrifugal compressor impeller was considered. Welding tests were carried out on the precipitation-hardened steel of the 17-4 PH type. Possibilities of joining centrifugal compressor impeller parts as important elements of turbo machines were considered. Two means of welding (111) and (114), as well as following heat treatment have been considered. The best results:

  9. Effect of Applied Potentials on Environmental Cracking Behavior of 17-4 PH Stainless Steel Weldments

    Microsoft Academic Search

    K. S. Raja; K. P. Rao

    1995-01-01

    The effects of anodic, cathodic, and open-circuit potentials (OCP) on the environmental cracking behavior of 17% Cr-4% Ni (17-4 [UNS S17400]) precipitation-hardenable (PH) stainless steel (SS) welds subjected to different thermal treatments were studied. Sheets of 17-4 PH SS 1.5 mm thick and in solution-treated condition were full-penetration welded autogenously using the gas tungsten arc welding process (GTAW). Weldments were

  10. Pitting Behavior of Type 17-4 PH Stainless Steel Weldments

    Microsoft Academic Search

    K. S. Raja; K. P. Rao

    1995-01-01

    Electrochemical methods of measuring pitting potentials (E{sub pit}) were used to study the pitting resistance of type 17% Cr-4% Ni (17-4, UNS S17400) precipitation hardenable (PH) stainless steel (SS) weldments. The main objectives were to evaluate the pitting resistance of the base metal, the heat-affected zone (HAZ), and the weld metal portions of 17-4 PH SS welds welded autogenously using

  11. Metal Injection Molding of PH 13-8 Mo Stainless Steel

    Microsoft Academic Search

    Dianne Chong

    1995-01-01

    Powder metal injection molding has been used for fabrication of near net shape parts from a number of ferrous alloys including carbonyl steels and stainless steels in the 3XX series and PH 17-4. However, no work has been performed to-date on the metal injection molding of PH 13-8 Mo. Because of a special application, this alloy was injection molded and

  12. STRESS-CORROSION CRACKING OF 17-4 PH STAINLESS STEEL

    Microsoft Academic Search

    1962-01-01

    Exposure of 17-4 PH stainless steel to a simulated HWCTR environment ; indicates that this alloy is susceptible to stress-corrosion cracking when aged ; at 900 deg F, but is not susceptible when aged at 1100 deg F. (auth);

  13. Failure of a 17-4 PH stainless steel sailboat propeller shaft

    Microsoft Academic Search

    C. Fahir Arisoy; Gokhan Ba?man; M. Kelami ?e?en

    2003-01-01

    In this study, a 17-4 PH precipitation hardening stainless steel propeller shaft failed in use when installed in a sailboat working in a marine environment. Failure analysis was conducted on the propeller shaft. Results indicate that the failure was caused by the fracture of the propeller shaft by torsional fatigue and stress corrosion cracking (SCC). SCC progressed transgranulary in the

  14. The characterization of small fatigue crack growth in PH13-8 molybdenum stainless steel

    Microsoft Academic Search

    Ohchang Jin

    2000-01-01

    The rotor hubs of Navy CH-46 helicopters have been made of 4340 steel and had extensive corrosion fatigue problems. Since these helicopters have to be used until the year 2020, the Navy decided to replace 4340 steel with PH 13-8 Mo stainless steel. Because the rotors are exposed to high frequency high cycle fatigue, small fatigue cracks are important in

  15. Failure analysis of holding yokes made of investment cast 17-4 PH stainless steel

    Microsoft Academic Search

    Ahmad Reza Etemadi; Peiman Behjati; Armin Emami; Sayyed Majd-al-Din Motiei; Saeed Mirsaeedi

    2011-01-01

    Holding yokes made of investment cast 17-4PH stainless steel were too soft (below 20HRC). Optical microscopy of the parts showed that there is a high fraction of retained austenite after oil quench due to high amount of molybdenum found in parts as an impurity. Subzero treatment in liquid nitrogen after solution heat treating was used to convert retained austenite to

  16. Activated gas nitriding of 17-4 PH stainless steel

    Microsoft Academic Search

    P. Kochma?ski; J. Nowacki

    2006-01-01

    Results of the investigation of nitrided precipitation-hardened steel 17-4 PH surface have been presented. The layers have been created as a result of the gas nitriding process in a partly dissociated ammonia. Hydrogen chloride admixture to ammonia was used as a steel surface activator. The influence of the steel heat treatment before nitriding on the diffusive process has been considered.

  17. Physical and mechanical properties of cast 17-4 PH stainless steel

    SciTech Connect

    Rack, H. J.

    1981-02-01

    The physical and mechanical properties of an overaged 17-4 PH stainless steel casting have been examined. The tensile and compressive properties of cast 17-4 PH are only influenced to a slight degree by changing test temperature and strain rate. However, both the Charpy impact energy and dynamic fracture toughness exhibit a tough-to-brittle transition with decreasing temperature - this transition being related to a change in fracture mode from ductile, dimple to cleavage-like. Finally, although the overaged 17-4 PH casting had a relatively low room temperature Charpy impact energy when compared to wrought 17-4 PH, its fracture toughness was at least comparable to that of wrought 17-4 PH. This observation suggests that prior correlations between Charpy impact energies and fracture toughness, as derived from wrought materials, must be approached with caution when applied to cast alloys.

  18. Electroless nickel plating on stainless steels and aluminum

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Procedures for applying an adherent electroless nickel plating on 303 SE, 304, and 17-7 PH stainless steels, and 7075 aluminum alloy was developed. When heat treated, the electroless nickel plating provides a hard surface coating on a high strength, corrosion resistant substrate.

  19. Embrittlement of laser surface-annealed 17-4 PH stainless steel

    Microsoft Academic Search

    L. W Tsay; T. Y Yang; M. C Young

    2001-01-01

    Stress corrosion cracking and fatigue crack growth behavior were determined in 17-4 PH stainless steel under various metallurgical conditions, including the H900 (482C\\/1 h), H1025 (552C\\/4 h) aging and laser surface annealing treatments. Peak-aged (H900) specimens locally irradiated by laser beam consisted of a portion of composite region (CR), in which comprised of soft laser-annealed (LA) zones on the outer

  20. Effects of ion implantation on friction and wear of stainless steels. [15-5PH

    Microsoft Academic Search

    L. E. Pope; F. G. Yost; D. M. Follstaedt; J. A. Knapp; S. T. Picraux

    1982-01-01

    Friction and wear of 304, 15-5 PH and 440C stainless steels and of pure Fe are shown to be reduced by ion implantation of Ti and C. Mechanically polished samples were ion implanted to fluences of 2 x 10¹⁵ Ti\\/mm² (90 to 180 keV) and 2 x 10¹⁵ C\\/mm² (30 keV); the implantation profiles of the two elements extended to

  1. Microstructural evolution in a 17-4 PH stainless steel after aging at 400 C

    Microsoft Academic Search

    M. Murayama; K. Hono; Y. Katayama

    1999-01-01

    The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 C, and long-term aging at 400 C, have been studied by atom probe field\\u000a ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite\\u000a with a small fraction of ?-ferrite. No precipitates are present

  2. Characterisation of mechanically milled 17-4 PH gas atomized stainless steel powders

    Microsoft Academic Search

    Cemil etinkaya; Tayfun F?nd?k; Sedat zbilen

    2007-01-01

    A laboratory scale Szegvari type vertical mechanical alloying (MA)\\/mechanical milling (MM) attritor for research purposes was designed and constructed at Gazi University. By using this attritor, optimum processing parameters such as milling time, milling speed (rev\\/min), diameter and the amount of milling balls, milling atmosphere were determined when MMing of gas atomized 17-4PH stainless steel powders were carried out. After

  3. The strength, fracture toughness, and low cycle fatigue behavior of 17-4 PH stainless steel

    Microsoft Academic Search

    H. J. Rack; David Kalish

    1974-01-01

    The influence of microstructure on the strength, fracture toughness and low cycle fatigue behavior of 17-4 PH stainless steel\\u000a has been examined. Aging hardening involves initial formation of coherent copper-rich clusters which transform to incoherent\\u000a fee ?-copper precipitates upon further aging. The changes in strength level and strain hardening rates observed during aging\\u000a are consistent with previously suggested models for

  4. Sintering densification and microstructural evolution of injection molding grade 17-4 PH stainless steel powder

    Microsoft Academic Search

    Yunxin Wu; Debby Blaine; Connie Schlaefer; Brian Marx; Randall M. German

    2002-01-01

    Densification behavior is investigated by means of dilatometry for powder-injection-molded (PIM) and die-compacted 17-4 PH\\u000a stainless steel during sintering in pure H2 and H2 + N2. The corresponding microstructural evolution is examined by quenching in a vertical furnace at various stages of sintering.\\u000a The results show that in comparison with pure H2, the H2 + N2 atmosphere retards densification and

  5. Processing and properties of highly porous 17-4 PH stainless steel

    Microsoft Academic Search

    I. Mutlu; E. Oktay

    2011-01-01

    Highly porous 17-4 PH stainless steel having porosities in the range of 3982% with an average pore size of around 700?m\\u000a was successfully fabricated using space holder technique in powder metallurgy. Irregular carbamide particles were used as\\u000a a space holder material. The final porosity was directly related to the added fraction of carbamide. The specimens were sintered\\u000a at either 1300C

  6. High-temperature fatigue crack growth behavior of 17-4 PH stainless steels

    Microsoft Academic Search

    Kuei-Chang Hsu; Chih-Kuang Lin

    2004-01-01

    The fatigue crack growth (FCG) behavior was investigated for 17-4 PH stainless steels in three heat-treated conditions, i.e., unaged (condition A), peak-aged (condition H900), and overaged (condition H1150), at temperatures ranging from 300 C to\\u000a 500 C. The high-temperature fatigue crack growth rates (FCGRs) of condition H1150 were increased with an increase in temperature.\\u000a However, for conditions A and H900

  7. Tensile and fatigue properties of 17-4 PH stainless steel at high temperatures

    Microsoft Academic Search

    Jui-Hung Wu; Chih-Kuang Lin

    2002-01-01

    The tensile and high-cycle fatigue properties for 17-4 PH* stainless steels in three different conditions were investigated\\u000a at temperatures ranging from room temperature to 400 C. Results indicated that the yield strength and fatigue strength for\\u000a the three conditions at a given temperature took the following order: condition H900 > condition A> condition H1150. The yield\\u000a strength of each condition

  8. Infrared brazing of Ti6Al4V and 17-4 PH stainless steel with a nickel barrier layer

    Microsoft Academic Search

    R. K. Shiue; S. K. Wu; C. H. Chan; C. S. Huang

    2006-01-01

    Infrared brazing of Ti-6Al-4V and 17-4 PH stainless steel using the BAg-8 filler metal was performed in this study. A nickel\\u000a barrier layer 10 m thick was introduced on the 17-4 PH stainless steel before infrared brazing. For the specimen that was\\u000a infrared brazed at 800 C and 850 C for less than 300 seconds, the Ni layer served as

  9. Effect of FeB additions on sintering characteristics of injection moulded 17-4PH stainless steel powder

    Microsoft Academic Search

    H. . Glsoy; S. Salman; S. zbek

    2004-01-01

    High density sintering of precipitation hardening stainless steel such as 17-4 PH involves a combination of relatively high temperature (>1350C) and extended sintering time. In this study, the effect of addition of FeB on sintering characteristics of 17-4 PH stainless steel was investigated. Addition of boron is promoted to get highly dense sintered steels. The amount of boron plays a

  10. Hot-cracking mechanism in CO laser beam welds of dissimilar metals involving PH martensitic stainless steels

    Microsoft Academic Search

    Cieslak

    1987-01-01

    Autogenous CO laser beam welds were made between Alloy HP 9-4-20 and both 15-5 PH and PH 13-8 Mo stainless steel. Small scale circular-patch test specimens revealed that the combination involving the Nb-bearing alloy, 15-5 PH, was far more crack susceptible than the combination involving the Nb-free alloy, PH 13-8 Mo. Analytical electron microscopy was used to identify an NbC\\/austenite

  11. Properties of cryogenically worked metals. [stainless steels

    NASA Technical Reports Server (NTRS)

    Schwartzberg, F. R.; Kiefer, T. F.

    1975-01-01

    A program was conducted to determine whether the mechanical properties of cryogenically worked 17-7PH stainless steel are suitable for service from ambient to cryogenic temperatures. It was determined that the stress corrosion resistance of the cryo-worked material is quite adequate for structural service. The tensile properties and fracture toughness at room temperature were comparable to titanium alloy 6Al-4V. However, at cryogenic temperatures, the properties were not sufficient to recommend consideration for structural service.

  12. Hydrogen embrittlement behavior of palladium modified PH 13-8 Mo stainless steel as a function of age hardening

    Microsoft Academic Search

    J. R. Scully; M. J. Cieslak; J. A. Van Den Avyle

    1994-01-01

    The hydrogen embrittlement (HE) susceptibility of precipitation age hardened stainless steels (17-4 PH, PH 15-5, PH 13-8 Mo, and others) is well established in the literature. Susceptibility is a strong function of strength and hence lower aging temperatures produce alloys which are more prone to HE. Recently it was shown that uniformly distributed PdAl precipitates improve the HE resistance of

  13. Effect of pH and oxygen on stress corrosion cracking of stainless steel in reactor moderator service

    Microsoft Academic Search

    Rideout

    1964-01-01

    Intergranular cracking of Type 304 stainless steel outlet nozzles in reactor moderator service prompted a broad program of laboratory studies to determine the cause of the failures. It was demonstrated that sensitized and pickled Type 304 stainless steel is extremely susceptible to both intergranular and transgranular chloride stress corrosion cracking in hot water of pH 4.5 to 5.0 which contains

  14. Effect of Casting Defect on Mechanical Properties of 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Yup; Lee, Joon-Hyun; Nahm, Seung-Hoon

    Damage and integrity evaluation techniques should be developed steadily in order to ensure the reliability and the economic efficiency of gas turbine engines. Casting defects may exist in most casting components of gas turbine engines, and the defects could give serious effect on mechanical properties and fracture toughness. Therefore, it is very important to understand the effect of casting defects on the above properties in order to predict the safety and life of components. In this study, specimens with internal casting defects, made from 17-4PH stainless steel, were prepared and evaluated and characterized based on the volume fraction of defects. The relation between mechanical properties such as tensile, low cycle fatigue and fracture toughness and volume fraction of defect has been investigated. As a result of the analysis, the mechanical properties of 17-4PH decreased as the defect volume fraction increased with very good linearity. The mechanical properties also showed an inversely proportional relationship to electrical resistivity.

  15. Flow Curve Analysis of 17-4 PH Stainless Steel under Hot Compression Test

    NASA Astrophysics Data System (ADS)

    Mirzadeh, Hamed; Najafizadeh, Abbas; Moazeny, Mohammad

    2009-12-01

    The hot compression behavior of a 17-4 PH stainless steel (AISI 630) has been investigated at temperatures of 950 C to 1150 C and strain rates of 10-3 to 10 s-1. Glass powder in the Rastegaev reservoirs of the specimen was used as a lubricant material. A step-by-step procedure for data analysis in the hot compression test was given. The work hardening rate analysis was performed to reveal if dynamic recrystallization (DRX) occurred. Many samples exhibited typical DRX stress-strain curves with a single peak stress followed by a gradual fall toward the steady-state stress. At low Zener-Hollomon ( Z) parameter, this material showed a new DRX flow behavior, which was called multiple transient steady state (MTSS). At high Z, as a result of adiabatic deformation heating, a drop in flow stress was observed. The general constitutive equations were used to determine the hot working constants of this material. Moreover, after a critical discussion, the deformation activation energy of 17-4 PH stainless steel was determined as 337 kJ/mol.

  16. Surface laser alloying of 17-4PH stainless steel steam turbine blades

    NASA Astrophysics Data System (ADS)

    Yao, Jianhua; Wang, Liang; Zhang, Qunli; Kong, Fanzhi; Lou, Chenghua; Chen, Zhijun

    2008-09-01

    As a known high-quality precipitation hardening stainless steel with high strength, high antifatigue, excellent corrosion resistance and good weldability, 17-4PH has been widely used to produce steam turbine blades. However, under the impact of high-speed steam and water droplets, the blades are prone to cavitation, which could lead to lower efficiency, shorter life time, and even accidents. In this article, the 17-4PH blade's surface was alloyed using a high power CO 2 laser. The microstructure and microhardness of hardened 17-4PH were tested by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy disperse spectroscopy (EDS) and a microhardness tester. After laser alloying, the surface layer was denser and the grain refined, while the microhardness of the surface (average 610HV 0.2) was about one times higher than that of the substrate material (330HV 0.2). The friction coefficient of the laser-alloyed 17-4PH layer was much lower than that of the substrate.

  17. The Structure and Properties of Diffusion Assisted Bonded Joints in 17-4 PH, Type 347, 15-5 PH and Nitronic 40 Stainless Steels

    NASA Technical Reports Server (NTRS)

    Wigley, D. A.

    1981-01-01

    Diffusion assisted bonds are formed in 17-4 PH, 15-5 PH, type 347 and Nitronic 40 stainless steels using electrodeposited copper as the bonding agent. The bonds are analyzed by conventional metallographic, electron microprobe analysis, and scanning electron microscopic techniques as well as Charpy V-notch impact tests at temperatures of 77 and 300 K. Results are discussed in terms of a postulated model for the bonding process.

  18. The characterization of small fatigue crack growth in PH13-8 molybdenum stainless steel

    NASA Astrophysics Data System (ADS)

    Jin, Ohchang

    The rotor hubs of Navy CH-46 helicopters have been made of 4340 steel and had extensive corrosion fatigue problems. Since these helicopters have to be used until the year 2020, the Navy decided to replace 4340 steel with PH 13-8 Mo stainless steel. Because the rotors are exposed to high frequency high cycle fatigue, small fatigue cracks are important in estimating remaining lifetime of the components. The objective of this study was to characterize the small crack growth behavior in the PH 13-8 Mo stainless steel under various loading conditions. Constant amplitude loading was conducted at the stress ratios, R, 0.1 and 0.4. The crack growth rate was affected by the microstructures in early stage of the growth, mainly by the size of the martensite packets and oscillated up to the crack length of 200 mum. It was found that the crack growth rate was little influenced by the stress amplitudes and stress ratios. In addition, the small crack growth rate was found to be similar to the long crack growth rate at R = 0.1 and 0.4. Overload tests and simple block loading were performed to understand load interaction effects on the small crack growth rate. The overload tests indicated that the crack growth rate was little affected by the overload. This might result from the fact that the overload ratio used in this study was low (<1.3). However, the results of the simple block loading showed overall crack growth retardation. The compressive residual stress present at the notch root of the specimen tested at R = 0.1 may lower the effective stress ratio, Reff, from 0.1 to negative R, and may result in the crack growth retardation. The small crack growth behavior was also examined under the saltwater. There was no difference in the crack growth rate between under air and under saltwater. In addition, the crack growth rate of the specimens tested under the saltwater was not affected by the test frequencies of 10, 1 and 0.1 Hz. It was shown that under the saltwater the PH 13-8 Mo stainless steel had an excellent corrosion fatigue resistance.

  19. Failure Maps for Rectangular 17-4PH Stainless Steel Sandwiched Foam Panels

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Ghosn, L. J.

    2007-01-01

    A new and innovative concept is proposed for designing lightweight fan blades for aircraft engines using commercially available 17-4PH precipitation hardened stainless steel. Rotating fan blades in aircraft engines experience a complex loading state consisting of combinations of centrifugal, distributed pressure and torsional loads. Theoretical failure plastic collapse maps, showing plots of the foam relative density versus face sheet thickness, t, normalized by the fan blade span length, L, have been generated for rectangular 17-4PH sandwiched foam panels under these three loading modes assuming three failure plastic collapse modes. These maps show that the 17-4PH sandwiched foam panels can fail by either the yielding of the face sheets, yielding of the foam core or wrinkling of the face sheets depending on foam relative density, the magnitude of t/L and the loading mode. The design envelop of a generic fan blade is superimposed on the maps to provide valuable insights on the probable failure modes in a sandwiched foam fan blade.

  20. Mechanical Properties of 17-4PH Stainless Steel Foam Panels

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Ghosn, L. J.; Lerch, B. a.; Hebsur, M.; Cosgriff, L. M.; Fedor, J.

    2007-01-01

    Rectangular 17-4PH stainless steel sandwiched foam panels were fabricated using a commercial manufacturing technique by brazing two sheets to a foam core. Microstructural observations and ultrasonic nondestructive evaluation of the panels revealed large variations in the quality of the brazed areas from one panel to the next as well as within the same panel. Shear tests conducted on specimens machined from the panels exhibited failures either in the brazed region or in the foam core for the poorly brazed and well-brazed samples, respectively. Compression tests were conducted on the foam cores to evaluate their elastic and plastic deformation behavior. These data were compared with published data on polymeric and metallic foams, and with theoretical deformation models proposed for open cell foams.

  1. Characterization of 17-4PH stainless steel powders produced by supersonic gas atomization

    NASA Astrophysics Data System (ADS)

    Zhao, Xin-Ming; Xu, Jun; Zhu, Xue-Xin; Zhang, Shao-Ming; Zhao, Wen-Dong; Yuan, Guo-Liang

    2012-01-01

    17-4PH stainless steel powders were prepared using a supersonic nozzle in a close-coupled gas atomization system. The characteristics of powder particles were carried out by means of a laser particle size analyzer, scanning electron microscopy (SEM), and the X-ray diffraction (XRD) technique. The results show that the mass median particle diameter is about 19.15 ?m. Three main types of surface microstructures are observed in the powders: well-developed dendrite, cellular, and cellular dendrite structure. The XRD measurements show that, as the particle size decreases, the amount of fcc phase gradually decreases and that of bcc phase increases. The cooling rate is inversely related to the particle size, i.e., it decreases with an increase in particle size.

  2. Mitigation of FOD and Corrosion Fatigue Damage in 17-4 PH Stainless Steel Compressor Blades with Surface Treatment

    Microsoft Academic Search

    Paul S. Prevy; N. Jayaraman; Ravi Ravindranath

    Compressor blades of a military aircraft turbine engine made of 17 -4 PH stainless steel have been reported to have blade edge foreign object damage (FOD), corrosion pitting, and erosion damage that reduce fatigue life. This paper reports the findings of a comprehensive investigation of the effect of residual compressive stresses, imparted by various surface treatments, to improve leading edge

  3. LOW PLASTICITY BURNISHING (LPB) TREATMENT TO MITIGATE FOD AND CORROSION FATIGUE DAMAGE IN 17-4 PH STAINLESS STEEL

    Microsoft Academic Search

    Paul S. Prevy; N. Jayaraman

    The benefits of applying low plasticity burnishing (LPB) to 17-4PH Stainless Steel (H1100) on both the fatigue and corrosion fatigue performance were compared with the shot peened (SP) and low stress ground (LSG) conditions. LPB treatment dramatically improved both the high cycle fatigue (HCF) performance and fatigue strength. The baseline LSG and SP treatments showed similar fatigue strengths of about

  4. Weldability, microstructure and properties of precipitation strenghtened martensitic stainless steels. [Custom 450; PH 13-8 Mo

    Microsoft Academic Search

    J. A. Brooks; W. R. Cieslak; W. M. Jr. Garrison

    1986-01-01

    We have investigated the influence of welding on the mechanical properties and corrosion resistance of two precipitation strengthened martensitic stainless steels: Custom 450 and PH 13-8 Mo. The two alloys exhibited very good weld cracking resistance, although the formation of a low melting NbC eutectic constituent did cause some solidification cracking in Custom 450. The effects of aging temperature on

  5. On the correlation between fracture toughness and precipitation hardening heat treatments in 15-5PH Stainless Steel

    Microsoft Academic Search

    M. Abdelshehid; K. Mahmodieh; K. Mori; L. Chen; P. Stoyanov; D. Davlantes; J. Foyos; J. Ogren; R CLARKJR; O. S. Es-Said

    2007-01-01

    In this study, the fracture toughness, Kq, and the yield strength of precipitation heat-treated Stainless Steel 15-5 PH was determined. Thirty six cylindrical tensile bars and eighteen compact tension C(T) specimens were tested. It was found that the high tolerance for solution heat treatment decreases the Kq value significantly, while the yield strength remains virtually unaltered.

  6. Effect of implantation species on the tribological response of stainless steel surfaces. [SS15-5PH

    Microsoft Academic Search

    L. E. Pope; S. T. Picraux; D. M. Follstaedt; J. A. Knapp; F. G. Yost

    1984-01-01

    The friction and wear properties of 304 and 15-5 PH stainless steels which were ion implanted with P and with P plus C have been examined and are compared with the properties of the same steels implanted with N and with Ti plus C. While benefits are obtained with the P and the P plus C implantation treatments, the N

  7. Influence of nickel boride additions on sintering behaviors of injection moulded 17-4 PH stainless steel powder

    Microsoft Academic Search

    H. zkan Glsoy

    2005-01-01

    Effect of nickel boride additions on sintering behavior of injection molded 17-4 PH stainless powder. With increases nickel boride amount, sintering time and temperature, relative density and mechanical properties of specimens increase. Sintering to full density was obtained with the addition of 1wt.% NiB at 1280C for 45min.

  8. Alloy Shrinkage Factors for the Investment Casting of 17-4PH Stainless Steel Parts

    NASA Astrophysics Data System (ADS)

    Sabau, Adrian S.; Porter, Wallace D.

    2008-04-01

    In this study, alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. The dimensions of the die tooling, wax pattern, and casting were measured using a coordinate measurement machine (CMM). For all the properties, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. A comparison between the predicted material property data and measured property data is made. It was found that most material properties were accurately predicted over most of the temperature range of the process. Several assumptions were made, in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted during heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed a different evolution on heating and cooling. Thus, one generic simulation was performed with thermal expansion obtained on heating, and another one was performed with thermal expansion obtained on cooling. The alloy dimensions were obtained from the numerical simulation results of the solidification, heat transfer, and deformation phenomena. As compared with experimental results, the numerical simulation results for the shrinkage factors were slightly overpredicted.

  9. Hydrogen embrittlement of stainless steels by lithium hydride

    Microsoft Academic Search

    Anthony W. Thompson

    1973-01-01

    Tests were made on 304L and 17-7 PH stainless steels in contact with LiH powder. Reduction in area relative to ductility in\\u000a air decreased for both alloys. It was essential that the LiH be baked in contact with the alloys for the ductility loss to\\u000a be observed; thermodynamic and kinetic evidence indicated that the LiH was reacting with surface oxides

  10. Microstructural evolution in a 17-4 PH stainless steel after aging at 400 C

    SciTech Connect

    Murayama, M.; Hono, K. [National Research Inst. for Metals, Tsukuba (Japan). Materials Physics Div.; Katayama, Y. [Toshiba Corp., Yokohama (Japan). Heavy Apparatus Engineering Lab.

    1999-02-01

    The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 C, and long-term aging at 400 C, have been studied by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite with a small fraction of {delta}-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the {delta}-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the {delta}-ferrite. After tempering for 4 hours as 580 C, coherent Cu particles precipitate in the martensite phase. At this stage, the Cr concentration in the martensite phase is still uniform. After 5000 hours aging at 400 C, the martensite spinodaly decomposes into Fe-rich {alpha} and Cr-enriched {alpha}{prime}. In addition, fine particles of the G-phase (structure type D8{sub a}, space group Fm{bar 3}m) enriched in Si, Ni, and Mn have been found in intimate contact with the Cu precipitates. Following spinodal decomposition of the martensite phase, G-phase precipitation occurs after long-term aging.

  11. Microstructural evolution in a 17-4 PH stainless steel after aging at 400 C

    NASA Astrophysics Data System (ADS)

    Murayama, M.; Hono, K.; Katayama, Y.

    1999-02-01

    The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 C, and long-term aging at 400 C, have been studied by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite with a small fraction of ?-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the ?-ferrite. After tempering for 4 hours at 580 C, coherent Cu particles precipitate in the martensite phase. At this stage, the Cr concentration in the martensite phase is still uniform. After 5000 hours aging at 400 C, the martensite spinodaly decomposes into Fe-rich ? and Cr-enriched ??. In addition, fine particles of the G-phase (structure type D8 a , space group Fmbar 3m) enriched in Si, Ni, and Mn have been found in intimate contact with the Cu precipitates. Following spinodal decomposition of the martensite phase, G-phase precipitation occurs after long-term aging.

  12. An investigation on the sintering behavior of 316L and 17-4PH stainless steel powders for graded composites

    Microsoft Academic Search

    A. Simchi; A. Rota; P. Imgrund

    2006-01-01

    This paper presents the densification and microstructure of bilayer structures made from 316L and 17-4PH stainless steels powders during sintering. The requirements for such objects could be magnetic properties at one area of the part and non-magnetic properties at another area of the object. A pressureless solid state sintering method in conjunction with a powder layering technique was used. The

  13. POSTIRRADIATION EXAMINATION OF 17-4 PH STAINLESS STEEL CONTROL ROD DRIVE RACK FROM SM1 REACTOR

    Microsoft Academic Search

    K. K. Klindt; A. E. Richt; W. C. Thurber

    1961-01-01

    A portion of the control rod drive system in the SM-1 Reactor, ; fabricated from l7-4 PH stainless steel, was examined at the Oak Ridge National ; Laboratory (ORNL) hot cells after successful operation in a pressurized-water ; environment for approximately three years. Examination included visual ; inspection, magnetic-particle tests, fluorescent penetrant tests, and ; metallography. No evidence of stress-corrosion

  14. Effect of molybdenum on SCC of 17-4PH stainless steel under different aging conditions in chloride solutions

    Microsoft Academic Search

    M. Karaminezhaad; S. Sharafi; K. Dalili

    2006-01-01

    Type 17-4 PH martensitic precipitation-hardenable stainless steel, having a combination of high mechanical properties and\\u000a good corrosion resistance is widely used in aerospace, chemical, and petrochemical and food industries This alloy has a high\\u000a resistance to stress corrosion cracking but age hardening treatment, increases its sensitivity to stress corrosion cracking.\\u000a There are several works investigating the influence of different aging

  15. Notch tensile properties of laser-surface-annealed 17-4 PH stainless steel in hydrogen-related environments

    Microsoft Academic Search

    L. W. Tsay; W. C. Lee; R. K. Shiue; J. K. Wu

    2002-01-01

    Slow displacement rate tensile tests were performed to determine the notched tensile strength (NTS) of 17-4 PH stainless steel with various microstructures in hydrogen-related environments. Solution-annealed (SA), peak-aged (H900), over-aged (H1025), and laser-annealed (LA) specimens were included in the study. Based on the results of NTS in air, the NTS loss in both gaseous hydrogen and H2S-saturated solution was used

  16. The effect of ageing upon the microstructure and mechanical properties of type 15-5 PH stainless steel

    Microsoft Academic Search

    H. R. Habibi Bajguirani

    2002-01-01

    Microstructures developed in commercial 15-5 PH precipitation-hardened stainless steel after different heat treatments have been studied. In the as received condition, two types of carbides, NbC and M7C3, were present. Age hardening involves initial formation of fine precipitates rich in copper. Conventional transmission electron microscopy (TEM) and high resolution electron microscopy (HREM) studies have revealed the formation of a 9R

  17. The corrosion and corrosionwear behaviour of plasma nitrided 17-4PH precipitation hardening stainless steel

    Microsoft Academic Search

    M. Esfandiari; H. Dong

    2007-01-01

    Plasma surface nitriding of 17-4 PH martensitic precipitation hardening stainless steels was conducted at 350C, 420C and 500C for 10h using a DC plasma nitriding unit, and the surface properties of the plasma surface engineered samples were systematically evaluated. Experimental results have shown that the surface properties of the plasma nitrided layers in terms of hardness, wear resistance, corrosion behaviour

  18. Dry sliding wear in injection molded 17-4 PH stainless steel powder with nickel boride additions

    Microsoft Academic Search

    H. zkan Glsoy

    2007-01-01

    Dry sliding wear behavior of injection molded 17-4 PH stainless steel powder with nickel boride additions has been studied on a pin-on-disc wear tester using an alloy steel pin and disc of hardness 63 HRC. The PIM alloys in the as sintered as well as in the precipitate-hardened conditions were investigated for their wear behavior. Wear rate was found to

  19. Microstructures and mechanical properties of injection molded 17-4PH stainless steel powder with nickel boride additions

    Microsoft Academic Search

    H. . Glsoy; S. Salman

    2005-01-01

    This paper describes the sintering of an injection molded 17-4 PH stainless steel with additions of nickel boride (NiB), with the aim of producing high mechanical properties. Boron is evaluated as the best sintering enhancing element in terms of densifying the iron-based materials by formation the liquid phase. Sintered density and mechanical properties were increased with the increased amount of

  20. Simulation of the sintering densification and shrinkage behavior of powder-injection-molded 17-4 PH stainless steel

    Microsoft Academic Search

    Young-Sam Kwon; Yunxin Wu; Pavan Suri; Randall M. German

    2004-01-01

    This study simulates the sintering behavior of powder-injection-molded 17-4 PH stainless steel to predict the geometry of\\u000a the sintered components. Sintering is considered as the viscous deformation process of a porous body under the influence of\\u000a sintering stress. Consequently, modified constitutive equations applicable to linear viscous, compressible material, based\\u000a on a continuum-mechanics approach, were utilized in simulating the sintering kinetics,

  1. Relationship between binder contents and mechanical properties of 17-4 ph stainless steel fabricated by PIM process and sintering

    Microsoft Academic Search

    K. A. Khalil; Sug Won Kim

    2006-01-01

    Mechanical properties and microstructures of 17-4 ph stainless steel parts produced using different binder contents (powder\\u000a loading) of powder injection molding (PIM) feedstock have been studied. The tensile and wear properties have been evaluated.\\u000a Wear tests were conducted by a pin-on-disk tribometer, without lubricant, at different loads and sliding distance. SEM examination\\u000a of the fracture sufaces revealed good particle bonding

  2. Effects of the Process Parameters on the Microstructure and Properties of Nitrided 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Lin, Yuanhua; Zeng, Dezhi; Yan, Jing; Fan, Hongyuan

    2013-04-01

    The effects of process parameters on the microstructure, microhardness, and dry-sliding wear behavior of plasma nitrided 17-4PH stainless steel were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and wear testing. The results show that a wear-resistant nitrided layer was formed on the surface of direct current plasma nitrided 17-4PH martensitic stainless steel. The microstructure and thickness of the nitrided layer is dependent on the treatment temperature rather than process pressure. XRD indicated that a single ? N phase was formed during nitriding at 623 K (350 C). When the temperature increased, the ? N phase disappeared and CrN transformed in the nitrided layer. The hardness measurement demonstrated that the hardness of the stainless substrate steel increased from 320 HV0.1 in the untreated condition increasing to about 1275HV0.1 after nitriding 623 K (350 C)/600 pa/4 hours. The extremely high values of the microhardness achieved by the great misfit-induced stress fields associated with the plenty of dislocation group and stacking fault. Dry-sliding wear resistance was improved by DC plasma nitriding. The best wear-resistance performance of a nitrided sample was obtained after nitriding at 673 K (350 C), when the single ? N-phase was produced and there were no CrN precipitates in the nitrided layer.

  3. Surface modification of 17-4PH stainless steel by DC plasma nitriding and titanium nitride film duplex treatment

    NASA Astrophysics Data System (ADS)

    Qi, F.; Leng, Y. X.; Huang, N.; Bai, B.; Zhang, P. Ch.

    2007-04-01

    17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.

  4. Effects of Temperature on Microstructure and Wear of Salt Bath Nitrided 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Lin, Yuanhua; Fan, Hongyuan; Zeng, Dezhi; Peng, Qian; Shen, Baoluo

    2012-08-01

    Salt bath nitriding of 17-4 PH martensitic precipitation hardening stainless steels was conducted at 610, 630, and 650 C for 2 h using a complex salt bath heat-treatment, and the properties of the nitrided surface were systematically evaluated. Experimental results revealed that the microstructure and phase constituents of the nitrided surface alloy are highly process condition dependent. When 17-4PH stainless steel was subjected to complex salt bathing nitriding, the main phase of the nitrided layer was expanded martensite (?'), expanded austenite (?N), CrN, Fe4N, and (Fe,Cr) x O y . In the sample nitrided above 610 C, the expanded martensite transformed into expanded austenite. But in the sample nitrided at 650 C, the expanded austenite decomposed into ?N and CrN. The decomposed ?N then disassembled into CrN and alpha again. The nitrided layer depth thickened intensively with the increasing nitriding temperature. The activation energy of nitriding in this salt bath was 125 5 kJ/mol.

  5. Weldability, microstructure and properties of precipitation strenghtened martensitic stainless steels. [Custom 450; PH 13-8 Mo

    SciTech Connect

    Brooks, J.A.; Cieslak, W.R.; Garrison, W.M. Jr.

    1986-01-01

    We have investigated the influence of welding on the mechanical properties and corrosion resistance of two precipitation strengthened martensitic stainless steels: Custom 450 and PH 13-8 Mo. The two alloys exhibited very good weld cracking resistance, although the formation of a low melting NbC eutectic constituent did cause some solidification cracking in Custom 450. The effects of aging temperature on tensile and impact properties were similar in the base metal and Gas-Tungsten-Arc (GTA) weldment for both alloys. The similarity of weld and base metal properties is attributed to the uniform precipitate distribution throughout the weld, as shown by Transmission Electron Microscopy (TEM) and electron microprobe analyses. The susceptibility to pitting corrosion was not impaired by aging or by welding, with the possible exception of a narrow band in the heat-affected zone (HAZ), and both materials were more resistant than 304 stainless steel. The narrow band is identified by electrochemical reactivation testing as a region of increased matrix activity likely caused by localized Cr and/or Mo depletion.

  6. An investigation into the effect of experimental parameters on powder grain size of the mechanically milled 17-4 PH stainless steel powders

    Microsoft Academic Search

    Cemil etinkaya; Tayfun Findik; Sedat zbilen

    2007-01-01

    In this study, a Szegvari type vertical mechanical alloying\\/milling attritor was designed and constructed for research purposes. By using this attritor, optimum processing parameters such as milling time, milling speed (rpm), diameter and the amount of the milling balls, milling atmosphere and raw material properties were determined when mechanical milling of gas and water atomised 17-4 PH stainless steel powders.

  7. 7 CFR 17.7 - Notice of sale procedures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Notice of sale procedures. 17.7 Section 17.7...Office of the Secretary of Agriculture SALES OF AGRICULTURAL COMMODITIES MADE AVAILABLE...1954, AS AMENDED 17.7 Notice of sale procedures. (a) Telephonic...

  8. Numerical simulation of the solidification microstructure of a 17-4PH stainless steel investment casting and its experimental verification

    NASA Astrophysics Data System (ADS)

    Li, You Yun; Tsai, DeChang; Hwang, Weng Sing

    2008-06-01

    The purpose of this study is to develop a technique of numerically simulating the microstructure of 17-4PH (precipitation hardening) stainless steel during investment casting. A cellular automation (CA) algorithm was adopted to simulate the nucleation and grain growth. First a calibration casting was made, and then by comparing the microstructures of the calibration casting with those simulated using different kinetic growth coefficients (a2, a3) in CA, the most appropriate set of values for a2 and a3 would be obtained. Then, this set of values was applied to the microstructure simulation of a separate casting, where the casting was actually made. Through this approach, this study has arrived at a set of growth kinetic coefficients from the calibration casting: a2 is 2.9 10-5, a3 is 1.49 10-7, which is then used to predict the microstructure of the other test casting. Consequently, a good correlation has been found between the microstructure of actual 17-4PH casting and the simulation result.

  9. A pH Sensor Based on a Stainless Steel Electrode Electrodeposited with Iridium Oxide

    ERIC Educational Resources Information Center

    Martinez, C. C. M.; Madrid, R. E.; Felice, C. J.

    2009-01-01

    A simple procedure to make an iridium oxide (IrO[subscript 2]) electrodeposited pH sensor, that can be used in a chemical, biomedical, or materials laboratory, is presented here. Some exercises, based on this sensor, that can be used to teach important concepts in the field of biomedical, biochemical, tissue, or materials engineering, are also

  10. Role of alloy additions on strengthening in 17-4 PH stainless steel

    NASA Astrophysics Data System (ADS)

    Murthy, Arpana Sudershan

    Alloy modifications by addition of niobium (Nb), vanadium (V), nitrogen (N) and cobalt (Co) to cast 17-4 PH steel were investigated to determine the effect on mechanical properties. Additions of Nb, V, and N increased the yield strength from 1120 MPa to 1310 MPa while decreased the room temperature charpy V notch (CVN) toughness from 20 J to four Joules. The addition of Co to cast 17-4 PH steel enhanced the yield strength and CVN toughness from 1140 MPa to 1290 MPa and from 3.7 J to 5.5 J, respectively. In the base 17-4 PH steel, an increase in block width from 2.27 0.10 ?m in the solution treated condition to 3.06 0.17 ?m upon aging at 755 K was measured using orientation image microscopy. Cobalt inhibited recrystallization and block boundary migration during aging resulting in a finer martensitic block structure. The influence of Co on copper (Cu) precipitation in steels was studied using atom probe tomography. A narrower precipitate size distribution was observed in the steels with Co addition. The concentration profile across the matrix / precipitate interface indicated rejection of Co atoms from the copper precipitates. This behavior was observed to be energetically favorable using first principle calculations. The activation energies for Cu precipitation increased from 205 kJ/ mol in the non-cobalt containing alloy, to 243 kJ/ mol, and 272 kJ/ mol in alloys with 3 wt. %Co, and 7 wt. % Co, respectively. The role of Co on Cu precipitation in cast 17-4 PH steel is proposed as follows: (i) Co is rejected out of the Cu precipitate and sets up a barrier to the growth of the Cu precipitate; (ii) results in Cu precipitates of smaller size and narrower distribution; (iii) the coarsening of Cu precipitates is inhibited; and (iv) the activation energy for Cu precipitation increases.

  11. Mechanism of austenitic transformation in the martensitic stainless steel of type PH 15-5

    Microsoft Academic Search

    H. R. HABIBI BAJGUIRANI

    1994-01-01

    By dilatometric analysis and TEM experiments, the martensite (M)+austenite (y) transformation and the formation of the precipitates in PH 15-5 alloy were studied between 20 and 1050C, using heating rate (Rh) , and cooling rate &) = 300OC.h-1. For this heating rate the M+ y transformation develops in two steps. Detailed analysis of the diffusion processes controlling the two stages

  12. Constituted oxides/nitrides on nitriding 304, 430 and 17-4 PH stainless steel in salt baths over the temperature range 723 to 923 K

    NASA Astrophysics Data System (ADS)

    Shih, Teng-Shih; Huang, Yung-Sen; Chen, Chi-Fan

    2011-10-01

    The progressively developed oxides and nitrides that form on nitriding 304, 430 and 17-4 PH stainless steel are analysed by X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) in this study. The experimental results show that the Cr contents and matrix structures (ferrite, austenite and martensite) play an important role in forming FeCr 2O 4, Cr 2O 3 and Fe 2O 3 oxides as well as nitrides. After a short immersion time, oxides of Cr 2O 3 and FeCr 2O 4 form in nitride films on 304 stainless steel samples. Fe 2O 3 oxide will subsequently form following an increasing immersion time. For the 430 stainless steel, Cr 2O 3 predominately forms after a short dipping time which hinders the growth of the nitride layer. As a result, this sample had the thinnest nitride film of the three for a given immersion time. After the formation of oxides, both CrN and Cr 2N were detected near the surface of the nitride films of three samples while Cr 2N phases formed in the deeper zone. The greatest amount of Fe 2O 3 oxide among the three samples was obtained on the nitriding 17-4 PH stainless steel which also had a high intensity count of N 1s.

  13. Influence of pH on the electrochemical behaviour of a duplex stainless steel in highly concentrated LiBr solutions

    Microsoft Academic Search

    V. Guin-Pina; A. Igual-Muoz; J. Garca-Antn

    2011-01-01

    The objective is to study the influence of pH on the corrosion and passive behaviour of duplex stainless steels (DSS) using potentiodynamic measurements, potentiostatic tests and electrochemical impedance spectroscopy (EIS).DSS are spontaneously passive in heavy brine LiBr solutions. Under potentiostatic conditions at applied anodic potentials within the passive domain an equivalent circuit with two time constants is the most suitable

  14. Metallurgical Analysis of Crack Initiation of Wire-Cut Electrical Discharge-Machined Spline Actuators Made of 17-4 PH Stainless Steel

    Microsoft Academic Search

    Ahmad-Reza Etemadi; Bahram Fazel; Armin Emami

    Spline actuators made of investment cast 17-4 PH (precipitation hardening) stainless steel were found to contain micro-cracks.\\u000a The cracked actuators were subjected to optical and scanning electron microscopy and hardness testing, which revealed that\\u000a the failure occurred due to fatigue crack initiation and growth after electrical discharge machining (EDM). The rehardened\\u000a layer produced by the EDM remained after machining, and

  15. Influence of hardness on the wear resistance of 17-4 PH stainless steel evaluated by the pin-on-disc testing

    Microsoft Academic Search

    J. D. Bressan; D. P. Daros; A. Sokolowski; R. A. Mesquita; C. A. Barbosa

    2008-01-01

    Present work aimed at investigating the wear resistance of AISI 630 (UNS S17400) or 17-4 PH stainless steel hardened by precipitation hardening or aging at various hardness levels. The PHs steels are an interesting family of steels for applying in highly stressed parts for its corrosion resistance and relative high hardness, attaining up to 49 HRC by low-temperature aging heat

  16. Constituted oxides\\/nitrides on nitriding 304, 430 and 17-4 PH stainless steel in salt baths over the temperature range 723 to 923 K

    Microsoft Academic Search

    Teng-Shih Shih; Yung-Sen Huang; Chi-Fan Chen

    2011-01-01

    The progressively developed oxides and nitrides that form on nitriding 304, 430 and 17-4 PH stainless steel are analysed by X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) in this study. The experimental results show that the Cr contents and matrix structures (ferrite, austenite and martensite) play an important role in forming FeCr2O4, Cr2O3 and Fe2O3 oxides as well as

  17. Microstructures of stainless steels exhibiting reduced friction and wear after implantation with Ti and C. [304; 15-5 PH; Nitronic 60; 440C

    Microsoft Academic Search

    D. M. Follstaedt; F. G. Yost; L. E. Pope

    1983-01-01

    Implantation of Ti and C into stainless steel discs of Types 304, 15-5 PH, Nitronic 60 and 440C has previously been reported to reduce wear depths by up to approx. 85% and friction by approx. 50% in unlubricated pin-on-disc tests. Our earlier studies relating microstructure to friction and wear results in Type 304 are first summarized: these indicate that the

  18. Nuclear microprobe analysis of wear tracks on ¹⁴N-implanted steels. [15-5 PH and 304 stainless steels

    Microsoft Academic Search

    B. L. Doyle; D. M. Follstaedt; S. T. Picraux; F. G. Yost; L. E. Pope; J. A. Knapp

    1984-01-01

    Two nuclear microbeam analysis techniques (3.7 MeV (..cap alpha..,p) and 6 MeV (..cap alpha..,..cap alpha..)) have been used to determine the local areal density of ¹⁴N which remains in wear tracks resulting from pin-on-disc testing of nitrogen implanted 15-5 PH and 304 stainless steels. The microbeam analysis shows that the extent of N migration into the 15-5 substrate was to

  19. The effect of 17-4PH stainless steel on the lifetime of a Pennzane lubricated Microwave Limb Sounder Antenna Actuator Assembly ball screw for the AURA spacecraft

    Microsoft Academic Search

    William R. Jones Jr.; Mark J. Jansen; Gun-Shing Chen; Jonathan Lam; Mark Balzer; John Lo; Mark Anderson; Joseph P. Schepis

    2005-01-01

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10% of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing

  20. Effects of residual carbon content on sintering shrinkage, microstructure and mechanical properties of injection molded 17-4 PH stainless steel

    Microsoft Academic Search

    Yunxin Wu; R. M. German; D. Blaine; B. Marx; C. Schlaefer

    2002-01-01

    Carbon contamination from the thermoplastic binder is an inherent problem with the metal powder injection molding process. Residual carbon in the compacts after debinding has a strong impact on the sintering process, microstructure, and mechanical properties. In this study, injection molded 17-4 PH stainless steel was debound to two levels of residual carbon, 0.203 0.014 wt% and 0.113

  1. Powder injection molding of a 17-4 PH stainless steel and the effect of sintering temperature on its microstructure and mechanical properties

    Microsoft Academic Search

    Hwan-Jin Sung; Tae Kwon Ha; Sangho Ahn; Young Won Chang

    2002-01-01

    The 17-4 PH stainless steel powders with average diameter of 10?m were injection-molded into plate-type tensile specimens. Sintering of the compacts was carried out at the various temperatures ranging from 900 to 1350C after solution extraction and thermal decomposition. Sintering behavior of the powder injection-molded specimens and room temperature tensile properties of sintered specimens were investigated. With increase in the

  2. Heat treatment of investment cast PH 13-8 Mo stainless steel; Part 2: Isothermal aging kinetics

    SciTech Connect

    Robino, C.V.; Cieslak, M.J. (Sandia National Labs., Albuquerque, NM (United States). Physical and Joining Metallurgy Dept.); Hochanadel, P.W.; Edwards, G.R. (Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering)

    1994-04-01

    The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 C to 593 C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 C, 538 C, 566 C, and 593 C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that [beta]-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the [beta]-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels.

  3. Influence of stress and pH on susceptibility of copper-containing type 304 stainless steels to stress corrosion cracking in sulfuric acid

    SciTech Connect

    Asawa, M.; Minoda, D. [Shinshu Univ., Nagano (Japan)

    1996-07-01

    Stress corrosion tests on type 304 (UNS S30400) stainless steels (SS) with 0.3 wt% or 1.3 wt% Cu addition were conducted in hot sulfuric acid-sodium hydroxide solutions under constant loads. Cracking susceptibility, corrosion morphology, average crack growth rate (CGR), and average uniform corrosion rate were examined as functions of pH, sulfate ion concentration, and applied stress. The steel with 0.3 wt% Cu exhibited stress corrosion cracking from pH 0.3 to 2.4, in which range the CGR was greater than the corrosion rate. The steel with 1.3 wt% Cu exhibited pit-like attack, crevice corrosion, pit-like attack with cracking, or cracking, depending upon pH ({minus}0.3 to 0.3) and stress level (150 MPa to 325 MPa).

  4. 43 CFR 17.7 - Procedure for effecting compliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin 17.7 Procedure for effecting compliance. (a) General. If there...

  5. 43 CFR 17.7 - Procedure for effecting compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin 17.7 Procedure for effecting compliance. (a) General. If there...

  6. 43 CFR 17.7 - Procedure for effecting compliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin 17.7 Procedure for effecting compliance. (a) General. If there...

  7. 43 CFR 17.7 - Procedure for effecting compliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin 17.7 Procedure for effecting compliance. (a) General. If there...

  8. 43 CFR 17.7 - Procedure for effecting compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin 17.7 Procedure for effecting compliance. (a) General. If there...

  9. Contribution of solution pH and buffer capacity to suppress intergranular stress corrosion cracking of sensitized type 304 stainless steel at 95 C

    SciTech Connect

    Zhang, S.; Shibata, T.; Haruna, T. (Osaka Univ., Suita, Osaka (Japan). Dept. of Materials Science and Processing)

    1999-05-01

    Controlling pH of high-temperature water to [approximately]pH 7 at 300 C by adding lithium hydroxide (LiOH) into the coolant system of a pressurized water reactor (PWR) successfully has been mitigating the corrosion of PWR component materials. The effects of solution pH and buffer capacity on intergranular stress corrosion cracking (IGSCC) of sensitized type 304 stainless steel ([SS] UNS S30400) was examined at 95 C by slow strain rate technique (SSRT) with an in-situ cracking observation system. It was found that an increase in solution pH or buffer capacity increased crack initiation time and decreased mean crack initiation frequency, but exerted almost no effect on crack propagation. This inhibition effect on IGSCC initiation was explained as resulting from a retarding effect of solution pH and buffer capacity on the decrease in pH at crack nuclei caused by the hydrolysis of metal ions dissolved when the passive film was ruptured by strain in SSRT.

  10. The effect of 17-4PH stainless steel on the lifetime of a Pennzane lubricated Microwave Limb Sounder Antenna Actuator Assembly ball screw for the AURA spacecraft

    NASA Astrophysics Data System (ADS)

    Jones, William R., Jr.; Jansen, Mark J.; Chen, Gun-Shing; Lam, Jonathan; Balzer, Mark; Lo, John; Anderson, Mark; Schepis, Joseph P.

    2005-07-01

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10% of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

  11. Effects of the Treating Time on Microstructure and Erosion Corrosion Behavior of Salt-Bath-Nitrided 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Lin, Yuanhua; Li, Mingxing; Fan, Hongyuan; Zeng, Dezhi; Xiong, Ji

    2013-08-01

    The effects of salt-bath nitriding time on the microstructure, microhardness, and erosion-corrosion behavior of nitrided 17-4PH stainless steel at 703 K (430 C) were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and erosion-corrosion testing. The experimental results revealed that the microstructure and phase constituents of the nitrided surface alloy are highly process condition dependent. When 17-4PH stainless steel was subjected to complex salt-bathing nitriding, the main phase of the nitrided layer was expanded martensite ( ?`), expanded austenite (S), CrN, Fe4N, and Fe2N. The thickness of nitrided layers increased with the treating time. The salt-bath nitriding improves effectively the surface hardness. The maximum values measured from the treated surface are observed to be 1100 HV0.1 for 40 hours approximately, which is about 3.5 times as hard as the untreated material (309 HV0.1). Low-temperature nitriding can improve the erosion-corrosion resistance against two-phase flow. The sample nitrided for 4 hours has the best corrosion resistance.

  12. Initation of pitting corrosion in martensitic stainless steels. [17-4PH; 13-8Mo; Custom 450

    Microsoft Academic Search

    W. R. Cieslak; R. E. Semarge; F. S. Bovard

    1986-01-01

    The form of localized corrosion known as pitting often initiates preferentially at microstructural inhomogeneities. The pit initiation resistance, therefore, is controlled by the characteristics of the initiation sites, rather than by the bulk material composition. This investigation correlates the pit initiation resistance, as measured by critical pitting potentials, with preferred pit initiation sites for 3 martensitic stainless steels. Pit initiation

  13. Initation of pitting corrosion in martensitic stainless steels. [17-4PH; 13-8Mo; Custom 450

    SciTech Connect

    Cieslak, W.R.; Semarge, R.E.; Bovard, F.S.

    1986-01-01

    The form of localized corrosion known as pitting often initiates preferentially at microstructural inhomogeneities. The pit initiation resistance, therefore, is controlled by the characteristics of the initiation sites, rather than by the bulk material composition. This investigation correlates the pit initiation resistance, as measured by critical pitting potentials, with preferred pit initiation sites for 3 martensitic stainless steels. Pit initiation sites are determined by secondary electron (SE) and backscattered electron (BSE) imaging and energy dispersive and wavelength dispersive spectrometries (EDS and WDS) with a scalling electron microscope (SEM) and an electron probe microanalyzer (EPMA).

  14. Stress corrosion study of PH13-8Mo stainless steel using the Slow Strain Rate Technique

    NASA Technical Reports Server (NTRS)

    Torres, Pablo D.

    1989-01-01

    The need for a fast and reliable method to study stress corrosion in metals has caused increased interest in the Slow Strain Rate Technique (SSRT) during the last few decades. PH13-8MoH950 and H1000 round tensile specimens were studied by this method. Percent reduction-in-area, time-to-failure, elongation at fracture, and fracture energy were used to express the loss in ductility, which has been used to indicate susceptibility to stress corrosion cracking (SCC). Results from a 3.5 percent salt solution (corrosive medium) were compared to those in air (inert medium). A tendency to early failure was found when testing in the vicinity of 1.0 x 10(-6) mm/mm/sec in the 3.5 percent salt solution. PH13-8Mo H1000 was found to be less likely to suffer SCC than PH13-8Mo H950. This program showed that the SSRT is promising for the SCC characterization of metals and results can be obtained in much shorter times (18 hr for PH steels) than those required using conventional techniques.

  15. An investigation of the high-temperature and solidification microstructures of PH 13-8 Mo stainless steel

    Microsoft Academic Search

    M. J. Cieslak; C. R. Hills; P. F. Hlava; S. A. David

    1990-01-01

    Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were\\u000a used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 C\\/s, this\\u000a alloy begins to transform from austenite to ?-ferrite at ?1350 C. Transformation is complete by ?1435 C. The solidus is\\u000a reached at ?1447 C,

  16. An investigation of the high-temperature and solidification microstructures of PH 13-8 Mo stainless steel

    Microsoft Academic Search

    M. J. Cieslak; C. R. Hills; P. F. Hlava; S. A. David

    1990-01-01

    Differential thermal analysis (DTA), high-temperature water-quench (WQ) experiments, and optical and electron microscopy were used to establish the near-solidus and solidification microstructures in PH 13-8 Mo. On heating at a rate of 0. 33 C\\/s, this alloy begins to transform from austenite to delta-ferrite at ≈1350 C. Transformation is complete by ≈1435 C. The solidus is reached at ≈1447 C,

  17. Microstructure and dry-sliding wear properties of DC plasma nitrided 17-4 PH stainless steel

    NASA Astrophysics Data System (ADS)

    Li, Gui-jiang; Wang, Jun; Li, Cong; Peng, Qian; Gao, Jian; Shen, Bao-luo

    2008-05-01

    An attempt that the precipitation hardening steel 17-4PH was conducted by DC plasma nitriding (DCPN) is made to develop a kind of candidate material for nuclear reactor. Nitriding process performed at temperature ? 400 C takes effect on creation of the layers composed of S-phase (expanded austenite) and ?N' (expanded martensite). Up to the temperature of 420 C, the S-phase peaks disappear due to the transformation occurrence (S-phase ? ?N' + CrN). For the samples nitrided at temperature ? 450 C, no evidence of ?N' is found owing to a precipitation ( ?N'??+CrN) taking place. For the 480 C/4 h treated sample, it is the surface microhardness that plays the lead role in the wear rate reduction but the surface roughness; while for the 400 C/4 h treated sample, it is both of the surface roughness and the S-phase formation. Dry sliding wear of the untreated 17-4PH is mainly characterized by strong adhesion, abrasion and oxidation mechanism. Samples nitrided at 400 C which is dominated by slight abrasion and plastic deformation exhibit the best dry sliding wear resistance compared to the samples nitrided at other temperatures.

  18. THE EFFECT OF 17-4PH STAINLESS STEEL ON THE LIFETIME OF A PENNZANE LUBRICATED MICROWAVE LIMB SOUNDER ANTENNA ACTUATOR ASSEMBL Y BALL SCREW FOR THE AURA SPACECRAFT

    Microsoft Academic Search

    William R. Jones; Mark J. Jansen; Jonathan Lam; Mark Balzer; John Lo; Joseph P. Schepis; Mark Anderson

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss w ere noted when approximately 10% of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  20. The Effect of 17-4 PH Stainless Steel on the Lifetime of a Pennzane(Trademark) Lubricated Microwave Limb Sounder Antenna Actuator Assembly Ball Screw for the AURA Spacecraft

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Jansen, Mark J.; Chen, Gun-Shing; Lam, Jonathan; Balzer, Mark; Anderson, Mark; Lo, John; Schepis, Joseph P.

    2005-01-01

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10 percent of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50 C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

  1. THE PHYSICAL METALLURGY OF PRECIPITATION-HARDENABLE STAINLESS STEELS

    Microsoft Academic Search

    D. C. Ludwigson; A. M. Hall

    1959-01-01

    The present knowledge on the physical metallurgy of precipitation-; hardenable stainless steels is presented. The alloys discussed include the ; martensitic types (Stainless W and 17-4 PH), the semiaustenitic types (177 PH, PH ; 15-7 Mo, AM 350, and AM 355), and the austenitic types (A-286 and HNM). The ; areas of metallurgy common to most or all of these

  2. Tool wear and tool life in end milling of 155 PH stainless steel under different cooling and lubrication conditions

    Microsoft Academic Search

    Aldo Braghini Junior; Anselmo Eduardo Diniz; Fernando Teixeira Filho

    2009-01-01

    Most of the machining operations on stainless steel alloys are carried out with cutting fluid due to the poor machinability\\u000a of this kind of material. Tool wear mechanisms are directly influenced by the cooling and lubrication condition to which the\\u000a tool is exposed, especially in interrupted cutting processes. This work investigates tool wear mechanisms for an end milling\\u000a operation of

  3. 47 CFR 17.7 - Antenna structures requiring notification to the FAA.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Antenna structures requiring notification to the...CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES Federal Aviation Administration Notification Criteria 17.7 Antenna structures requiring notification to...

  4. 47 CFR 17.7 - Antenna structures requiring notification to the FAA.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Antenna structures requiring notification to the...CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES Federal Aviation Administration Notification Criteria 17.7 Antenna structures requiring notification to...

  5. 47 CFR 17.7 - Antenna structures requiring notification to the FAA.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Antenna structures requiring notification to the...CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES Federal Aviation Administration Notification Criteria 17.7 Antenna structures requiring notification to...

  6. 47 CFR 17.7 - Antenna structures requiring notification to the FAA.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Antenna structures requiring notification to the...CONSTRUCTION, MARKING, AND LIGHTING OF ANTENNA STRUCTURES Federal Aviation Administration Notification Criteria 17.7 Antenna structures requiring notification to...

  7. Bladed-shrouded-disc aeroelastic analyses: Computer program updates in NASTRAN level 17.7

    NASA Technical Reports Server (NTRS)

    Gallo, A. M.; Elchuri, V.; Skalski, S. C.

    1981-01-01

    In October 1979, a computer program based on the state-of-the-art compressor and structural technologies applied to bladed-shrouded-disc was developed. The program was more operational in NASTRAN Level 16. The bladed disc computer program was updated for operation in NASTRAN Level 17.7. The supersonic cascade unsteady aerodynamics routine UCAS, delivered as part of the NASTRAN Level 16 program was recorded to improve its execution time. These improvements are presented.

  8. UNIT 17.7Chromatin Immunoprecipitation for Determining the Association of Proteins

    E-print Network

    Gozani, Or

    IP protocol for cells of the baker's yeast Saccharomyces cerevisiae (see Basic Protocol); however, it is also PROTOCOL CHROMATIN IMMUNOPRECIPITATION Materials Saccharomyces cerevisae cells to be studied 37 mg/ml Pronase (Roche) in TBS; store up to 1 year at -20 C TE buffer, pH 7.5 (APPENDIX 2A) 20 mg

  9. 47 CFR 15.252 - Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0 GHz.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29...Additional Provisions 15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and...

  10. 47 CFR 15.252 - Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0 GHz.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29...Additional Provisions 15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and...

  11. 47 CFR 15.252 - Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0 GHz.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29...Additional Provisions 15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and...

  12. 47 CFR 15.252 - Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0 GHz.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29...Additional Provisions 15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and...

  13. 47 CFR 15.252 - Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29.0 GHz.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and 23.12-29...Additional Provisions 15.252 Operation of wideband vehicular radar systems within the bands 16.2-17.7 GHz and...

  14. Stress corrosion cracking evaluation of martensitic precipitation hardening stainless steels

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.; Nelson, E. E.

    1980-01-01

    The resistance of the martensitic precipitation hardening stainless steels PH13-8Mo, 15-5PH, and 17-4PH to stress corrosion cracking was investigated. Round tensile and c-ring type specimens taken from several heats of the three alloys were stressed up to 100 percent of their yield strengths and exposed to alternate immersion in salt water, to salt spray, and to a seacoast environment. The results indicate that 15-5PH is highly resistant to stress corrosion cracking in conditions H1000 and H1050 and is moderately resistant in condition H900. The stress corrosion cracking resistance of PH13-8Mo and 17-4PH stainless steels in conditions H1000 and H1050 was sensitive to mill heats and ranged from low to high among the several heats included in the tests. Based on a comparison with data from seacoast environmental tests, it is apparent that alternate immersion in 3.5 percent salt water is not a suitable medium for accelerated stress corrosion testing of these pH stainless steels.

  15. Capacitance behaviour of passive films on ferritic and austenitic stainless steel

    Microsoft Academic Search

    M. J. Carmezim; A. M. Simes; M. F. Montemor; M. Da Cunha Belo

    2005-01-01

    The electrochemical behaviour of passive films formed on one austenitic stainless steel (AISI 304) and one ferritic stainless steel (AISI 446) in solutions with pH between 0.6 and 8.4 was studied by capacitance measurements and photocurrent spectroscopy. Compositional characterization of the passive films was done by X-ray photoelectron spectroscopy. The capacitance increases with decreasing pH. Doping densities evaluated from MottSchottky

  16. PRECIPITATION-HARDENING STAINLESS STEELS IN WATER-COOLED REACTORS

    Microsoft Academic Search

    M. C. Rowland; W. R. Sr. Smith

    1962-01-01

    A study is made of the stress corrosion susceptibiity of unirradiated ; precipitation-hardening stainless steels. This study is made because of the ; failures encouatered with these materials in the Dresden and Vallecltos boiling ; water reactors. Service experience, static steam autoclave tests, and dynamic ; water and steam corrosion loop tests have demonstrated that 17-4 PH in the high-;

  17. Effect of powder loading on metal injection molding stainless steels

    Microsoft Academic Search

    Yimin Li; Liujun Li; K. A. Khalil

    2007-01-01

    Powder loading is one of the most critical factors which has important influence on metal injection molding processes. Using the gas atomized spherical 17-4 PH stainless steel powder and the binder of 65% PW+30% EVA+5% SA, four kinds of feedstocks were prepared at the powder loading of 60, 64, 68 and 72%, respectively. The effects of the powder loading on

  18. Chromium-Makes stainless steel stainless

    USGS Publications Warehouse

    Kropschot, S.J.; Doebrich, Jeff

    2010-01-01

    Chromium, a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point, is a silvery white, hard, and bright metal plating on steel and other material. Commonly known as chrome, it is one of the most important and indispensable industrial metals because of its hardness and resistance to corrosion. But it is used for more than the production of stainless steel and nonferrous alloys; it is also used to create pigments and chemicals used to process leather.

  19. Corrosion of Welded Stainless Steel

    Microsoft Academic Search

    T. Defee; H. G. Wheat; S. Landsberger

    Stainless steels are usually chosen for their low corrosion rates and in some cases their resistance to pitting. In addition, when welded stainless steels are used, measures are taken to reduce the susceptibility to sensitization and other forms of corrosion. Additional care may have to be taken when the environmental conditions associated with the use of the stainless steels are

  20. Welding of Stainless Materials

    NASA Technical Reports Server (NTRS)

    Bull, H; Johnson, Lawrence

    1929-01-01

    It would appear that welds in some stainless steels, heat-treated in some practicable way, will probably be found to have all the resistance to corrosion that is required for aircraft. Certainly these structures are not subjected to the severe conditions that are found in chemical plants.

  1. Effect of microstructure on pitting and corrosion fatigue of 17-4 PH turbine blade steel in chloride environments

    Microsoft Academic Search

    B. C. Syrett; R. Viswanathan

    1982-01-01

    Depending on its heat treatment, 17-4 PH stainless steel may contain significant levels of reformed austenite and untempered martensite in a matrix of tempered martensite. Shot peening can cause changes in the microstructure of the surface layers by transforming the austenite to untempered martensite. The effect of these microstructural varations on the resistance of 17-4 PH stainless steel to pitting

  2. Improvement of the thermal stability of sintered Nd-Fe-B magnets by intergranular addition of Dy{sub 82.3}Co{sub 17.7}

    SciTech Connect

    Zhang, Xiaofeng; Guo, Shuai; Yan, Changjiang; Cai, Lingwen; Chen, Renjie; Yan, Aru, E-mail: aruyan@nimte.ac.cn [Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang (China); Lee, Don [University of Dayton, Dayton, Ohio 45469 (United States)

    2014-05-07

    In this study, microstructure and magnetic properties of sintered Nd-Fe-B magnets with addition of Dy{sub 82.3}Co{sub 17.7} (wt.?%) were investigated. By adding a small amount of Dy{sub 82.3}Co{sub 17.7}, the coercivity is improved greatly, and the irreversible loss is decreased sharply. The increase of Curie temperature suggests that Co atoms have entered into the 2:14:1 main phase. Microstructural analysis indicates that a well-developed core-shell structure was formed in the magnets with the addition of Dy{sub 82.3}Co{sub 17.7}. The improvement of magnetic properties can be attributed to the microstructural modification and the intrinsic properties' improvement.

  3. A SURVEY OF THE CORROSION OF MARTENSITIC AND FERRITIC STAINLESS STEELS IN PRESSURIZED WATER

    Microsoft Academic Search

    R. J. Beaver; C. F. Jr. Leitten

    1963-01-01

    The corrosion resistance of mantensitic and ferritic austenitic ; stainless steels and carbon steels in pressurized water at 500 to 600 deg F is ; compared. Included are specific out-of-pile data for austenitic stainless ; steels, AISI types types 410, 420, 431, and 440C; the ferritic AISI types 430, ; 442, and 446; the precipitation-hardening type 17-4PH; and carbon steels,

  4. Low-chromium stainless steels

    NASA Technical Reports Server (NTRS)

    Barrett, C. A.; Gyorgak, C. A.; Stephens, J. R.

    1978-01-01

    Two modified stainless-steel formulations, with only two-thirds chromium content found in conventional type 304, have mechanical and chemical properties comparable to type 304. Low-chromium stainless steels have potential uses in heat exchangers, transfer lines for chemicals, automobile trim, and other applications.

  5. Corrosion resistance of stainless steels

    Microsoft Academic Search

    1995-01-01

    This book reviews the mechanisms and forms of corrosion and examines the corrosion of stainless steels and similar chromium-bearing nickel containing higher alloys, detailing various corrosive environments including atmospheric and fire-side corrosion, corrosion by water and soil, and corrosion caused by particular industrial processes. It provides information on specific groups and grades of stainless steels; summarizes typical applications for specific

  6. The transpassive dissolution mechanism of highly alloyed stainless steels

    Microsoft Academic Search

    Iva Betova; Martin Bojinov; Timo Laitinen; Kari Mkel; Pekka Pohjanne; Timo Saario

    2002-01-01

    The effect of pH and solution anion on the kinetics of transpassive dissolution of highly alloyed austenitic stainless steels (AISI 904L, 254SMO and 654SMO) was studied by a combination of electrochemical techniques. The experiments were performed in 0.5 M sulphate and 0.5 M chloride solutions, and in an equimolar mixture of the two. The transpassive dissolution was found to start

  7. The transpassive dissolution mechanism of highly alloyed stainless steels

    Microsoft Academic Search

    Iva Betova; Martin Bojinov; Timo Laitinen; Kari Mkel; Pekka Pohjanne; Timo Saario

    2002-01-01

    The transpassive dissolution of austenitic stainless steels (AISI 316L, AISI 904L, 254SMO and 654SMO) in a 0.5 M sulphate solution with pH 2 was studied by conventional and rotating ringdisc voltammetry, as well as electrochemical impedance spectroscopy. The main process in the transpassive potential region was found to be the release of soluble Cr(VI), while small amounts of lower-valency Cr

  8. Crack Initiation Mechanisms for Corrosion Fatigue of Austenitic Stainless Steel

    Microsoft Academic Search

    Y. R. Qian; J. R. Cahoon

    1997-01-01

    Corrosion fatigue tests on annealed type 316 stainless steel showed the maximum stress level for failure in 0.5 M sodium chloride aqueous solution at pH = 4.2 was one-third lower than in air after a similar number of cycles. Crack initiation mechanisms of corrosion fatigue were studied by scanning electron microscopy of prepolished specimen surfaces. Fatigue tests were conducted at

  9. 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.

  10. 19.6 A 0.27V 30MHz 17.7nJ/transform 1024-pt Complex FFT Core with Super-Pipelining

    E-print Network

    Kambhampati, Subbarao

    19.6 A 0.27V 30MHz 17.7nJ/transform 1024-pt Complex FFT Core with Super-Pipelining Mingoo Seok1 on an FFT core in 65nm CMOS. Pipelining is a well-known method to improve performance, typically to the multipliers in an FFT core, we find that it consumes minimum energy when pipelined in 6 stages at a stage

  11. Stress corrosion cracking of 2205 duplex stainless steel in H 2 SCO 2 environment

    Microsoft Academic Search

    Z. Y. Liu; C. F. Dong; X. G. Li; Q. Zhi; Y. F. Cheng

    2009-01-01

    Stress corrosion cracking (SCC) behavior of 2205 duplex stainless steel (DSS) in H2SCO2 environment was investigated by electrochemical measurements, slow strain rate test (SSRT), and scanning electron microscopy\\u000a (SEM) characterization. Results demonstrated that the passive current density of steel increases with the decrease of solution\\u000a pH and the presence of CO2. When solutions pH was 2.7, the steel SCC in

  12. Weld microstructure development and properties of precipitation-strengthened martensitic stainless steels

    Microsoft Academic Search

    J. A. Brooks; W. R. Jr. Garrison

    1999-01-01

    The weld microstructural evolution, mechanical properties and solidification cracking susceptibility of three precipitation-strengthened martensitic stainless steels--PH 13-8 Mo, Custom 450 and 15-5 PH--were investigated. Liquid tin quenching of gas tungsten arc welds revealed that all three welds solidified as single-phase ferrite with a high degree of microsegregation. However, during further solidification and cooling almost complete homogenization occurred as a result

  13. Achievement of a superpolish on bare stainless steel

    NASA Astrophysics Data System (ADS)

    Howells, Malcolm R.; Casstevens, John M.

    1997-11-01

    We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 angstroms, as measured by an optical profiler with a bandwidth 0.29 - 100 mm-1. The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufacturability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible reasons for its unusual stability and polishability.

  14. Achievement of a superpolish on bare stainless steel

    SciTech Connect

    Howells, M.R. [Lawrence Berkeley National Lab., CA (United States); Casstevens, J. [Dallas Optical Systems, Rockwell, TX (United States)

    1997-08-01

    We report the achievement of a superpolished surface, suitable for x-ray reflection, on bare stainless steel. The rms roughness obtained on various samples varied from 2.2 to 4.2 {angstrom}, as measured by an optical profiler with a bandwidth 0.29-100 mm{sup -1}. The type 17-4 PH precipitation-hardening stainless steel used to make the mirrors is also capable of ultrastability and has good manufactureability. This combination of properties makes it an excellent candidate material for mirror substrates. We describe the successful utilization of this type of steel in making elliptical-cylinder mirrors for a soft-x-ray microprobe system at the Advanced Light Source, and discuss possible for its unusual stability and polishability.

  15. Metallurgical investigations of pulsed Nd:YAG laser welding of AISI 321 and AISI 630 stainless steels

    Microsoft Academic Search

    S. A. A. Akbari Mousavi; A. R. Sufizadeh

    2009-01-01

    In this paper, pulsed Nd:YAG laser welding of 321 austenitic stainless steel and 630 (17-4PH) precipitation hardening stainless steel is being studied. The joints had a circular geometry and butt welded. Studies were focused on the effects of laser power, beam diameter and pulse duration on the depth and width of the welds. Microstructures of the welded joints were investigated

  16. Effect of nitrogen-mediated changes in alkalinity on ph control and CO supply in intensive microalgal cultures

    Microsoft Academic Search

    Joel C. Goldman; Mark R. Dennett; Carol B. Riley

    1982-01-01

    The freshwater alga Scenedesmus obliquus was grown in continuous culture at a fixed dilution rate of 0.5 per day, but at varying pH in the range 4.17-10.67. The pH was regulated in the range 4.17-7.67 by continuously bubbling 1% CO-enriched air into the cultures and by varying the source of nitrogen (NO-, NH+, or urea) in the growth medium, which,

  17. Ratcheting Behavior of a Non-conventional Stainless Steel and Associated Microstructural Variations

    NASA Astrophysics Data System (ADS)

    Sahu, Lopamudra; Mishra, Awanish Kumar; Dutta, Krishna

    2014-09-01

    Ratcheting fatigue behavior of a non-conventional stainless steel X12CrMnNiN17-7-5 has been investigated with varying combinations of mean stress (?m) and stress amplitude (?a) at room temperature using a servo-hydraulic universal testing machine. X-ray diffraction profile analysis has been carried out for assessing possible martensitic phase transformation in the steel subjected to ratcheting deformation. The results indicate that ratcheting strain as well as volume fraction of martensite increases with increasing ?m and/or ?a; the phenomenon of strain accumulation is considered to be governed by the associated mechanics of cyclic loading, increased plastic damage as well as martensitic transformation. A correlation between strain produced by ratcheting deformation and martensitic transformation has been established.

  18. Ratcheting Behavior of a Non-conventional Stainless Steel and Associated Microstructural Variations

    NASA Astrophysics Data System (ADS)

    Sahu, Lopamudra; Mishra, Awanish Kumar; Dutta, Krishna

    2014-11-01

    Ratcheting fatigue behavior of a non-conventional stainless steel X12CrMnNiN17-7-5 has been investigated with varying combinations of mean stress (?m) and stress amplitude (?a) at room temperature using a servo-hydraulic universal testing machine. X-ray diffraction profile analysis has been carried out for assessing possible martensitic phase transformation in the steel subjected to ratcheting deformation. The results indicate that ratcheting strain as well as volume fraction of martensite increases with increasing ?m and/or ?a; the phenomenon of strain accumulation is considered to be governed by the associated mechanics of cyclic loading, increased plastic damage as well as martensitic transformation. A correlation between strain produced by ratcheting deformation and martensitic transformation has been established.

  19. Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9

    SciTech Connect

    Farmer, J C; Haslam, J; Day, S D; Lian, T; Saw, C K; Hailey, P D; Choi, J S; Rebak, R B; Yang, N; Payer, J H; Perepezko, J H; Hildal, K; Lavernia, E J; Ajdelsztajn, L; Branagan, D J; Buffa, E J; Aprigliano, L F

    2007-04-25

    An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was prepared as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. During electrochemical testing in several environments, including seawater at 90 C, the passive film stability was found to be comparable to that of high-performance nickel-based alloys, and superior to that of stainless steels, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. This material also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. This material and its parent alloy maintained corrosion resistance up to the glass transition temperature, and remained in the amorphous state during exposure to relatively high neutron doses.

  20. pH Protocol

    NSDL National Science Digital Library

    The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

    2005-06-02

    The purpose of this resource is to measure the pH of water. Students use either a pH meter or pH paper to measure the pH. If using the pH meter, the meter needs to be calibrated with buffer solutions that have pH values of 4, 7, and 10.

  1. Physiology of dairy-associated Bacillus spp. over a wide pH range.

    PubMed

    Lindsay, D; Brzel, V S; Mostert, J F; von Holy, A

    2000-03-10

    Bacillus species isolated from alkaline wash solutions used for cleaning in place in South African dairy factories have been suggested to contaminate product contact surfaces of dairy processing equipment and result in post-pasteurization spoilage of milk and milk products. Growth and attachment of such Bacillus isolates under alkaline and acidic conditions have not been previously described. Therefore, the in vitro growth temperature and pH ranges, attachment abilities and hydrophobicity, and enzyme production capabilities of four Bacillus isolates (tentatively identified as B. subtilis115, B. pumilus122, B. licheniformis137 and B. cereus144) previously isolated from the alkaline wash solutions in a South African dairy were examined. Growth pH ranges were determined in buffered Standard One-like Nutrient Broth and in unbuffered 1% Milk Medium at pH values ranging from 3 to 12. Growth and attachment to stainless steel surfaces and production of protease and lipase enzymes were determined in 1% Milk Medium at pH 4, 7 and 10. Colony hydrophobicity of each isolate by the Direction of Spreading Method (DOS) was also determined at pH 4, 7 and 10. In addition, Arrhenius plots were used to examine the growth temperature ranges of the isolates. All isolates grew at pH values ranging from 4.5 to 9.5 in buffered Standard One-like Nutrient Broth, and from pH 4 to 10 in 1% Milk Medium. All isolates also attached to stainless steel at pH 4, 7 and 10 in 1% Milk Medium. Generally the attachment of B. subtilis115, B. pumilus122 and B. lichenformis137 to stainless steel surfaces was enhanced at pH 4 and 10, compared to pH 7. By contrast, the best attachment of B. cereus144 cells to stainless steel surfaces was at pH 7. Planktonic and attached cells of all isolates produced proteolytic enzymes at pH 7 and 10, but not at pH 4. Similarly, planktonic and attached cells of B. subtilis115, B. pumilus122 and B. licheniformis137 produced lipolytic enzymes at pH 7 and 10, and weak lipolysis was observed at pH 4. The Bacillus cereus144 isolate showed no lipolytic activity at pH 10. All isolates exhibited low hydrophobic properties at all pH values even though attachment to stainless steel at the same pH values occurred. None of the isolates grew below 11 degrees C or above 56 degrees C, and optimum growth temperatures were in the high mesophilic range (36-44 degrees C). PMID:10746574

  2. Comparative Study on the Corrosion Resistance of Fe-Based Amorphous Metal, Borated Stainless Steel and Ni-Cr-Mo-Gd Alloy

    SciTech Connect

    Lian, Tiangan; Day, Daniel; Hailey, Phillip; Choi, Jor-Shan; Farmer, Joseph [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

    2007-07-01

    Iron-based amorphous alloy Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} was compared to borated stainless steel and Ni-Cr-Mo-Gd alloy on their corrosion resistance in various high-concentration chloride solutions. The melt-spun ribbon of this iron-based amorphous alloy have demonstrated a better corrosion resistance than the bulk borated stainless steel and the bulk Ni-Cr-Mo-Gd alloy, in high-concentration chloride brines at temperatures 90 deg. C or higher. (authors)

  3. Hydrogen damage in stainless steel

    Microsoft Academic Search

    Caskey; G. R. Jr

    1981-01-01

    Hydrogen damage has been studied in a wide variety of stainless steels. Both internal and external hydrogen damage were evaluated by ductility or J-integral under rising tensile loads and by fractography. Analysis of the data has emphasized the potential effects of strain-induced martensite on hydrogen damage. Strain-induced martensite was neither necessary nor sufficient for hydrogen damage in the alloys studied.

  4. Comminution of stainless steel powders

    Microsoft Academic Search

    B. A. Borok; R. P. Schchegoleva; L. S. Golubeva; F. S. Sariadi; E. M. Rabinovich

    1974-01-01

    1.Atmospheric milling in barrel type mixers at a powder-to-ball weight ratio of 1::2 is an effective means of comminuting stainless steel powders produced by the coreduction process. In the work described, milling for 27 h was found to increase the amount of the -0.063-mm fraction from ~15 to ~75% for a Kh18N15 steel powder and from ~24.6 to ~70%for a

  5. Nickel: makes stainless steel strong

    USGS Publications Warehouse

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  6. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Gold or stainless steel cusp. 872.3350 Section 872.3350...Devices 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made...

  7. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Gold or stainless steel cusp. 872.3350 Section 872.3350...Devices 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made...

  8. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Gold or stainless steel cusp. 872.3350 Section 872.3350...Devices 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made...

  9. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Gold or stainless steel cusp. 872.3350 Section 872.3350...Devices 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp is a prefabricated device made...

  10. Characterisation of severely deformed austenitic stainless steel wire

    E-print Network

    Cambridge, University of

    : Martensite, Mechanical Stabilization, Interface structure, Stainless steel Introduction Textiles woven using stainless steel threads have applications requiring softness, flexibility, abrasion resistanceCharacterisation of severely deformed austenitic stainless steel wire H. S. Wang1 , J. R. Yang1

  11. Stainless Steel Bipolar Plates Deposited with Multilayer Films for PEMFC Applications

    NASA Astrophysics Data System (ADS)

    Cho, Hyun; Yun, Young-Hoon

    2013-08-01

    A chromium nitride (CrN, Cr2N)/chromium (Cr)/indium-tin-oxide (ITO) system and a gold (Au)/titanium (Ti) system were separately deposited using a sputtering method and an E-beam method, respectively, onto stainless steel 316 and 304 plates. The XRD patterns of the deposited stainless steel plates showed the crystalline phase of typical indium-tin oxide and of metallic phases, such as chromium, gold, and the metal substrate, as well as those of external chromium nitride films. The nitride films were composed of two metal nitride phases that consisted of CrN and Cr2N compounds. The surface morphologies of the modified stainless steel bipolar plates were observed using atomic force microscopy and FE-SEM. The chromium nitride (CrN, Cr2N)/chromium (Cr)/indium-tin-oxide (ITO) multilayer that was formed on the stainless steel plates had a surface microstructural morphology that consisted of fine columnar grains 10 nm in diameter and 60 nm in length. The external gold films that were formed on the stainless steel plates had a grain microstructure approximately 100 nm in diameter. The grain size of the external surface of the stainless steel plates with the gold (Au)/titanium (Ti) system increased with increasing gold film thickness. The electrical resistances and water contact angles of the stainless steel bipolar plates that were covered with the multilayer films were examined as a function of the thickness of the ITO film or of the external gold film. In the corrosion test, ICP-MS results indicated that the gold (Au)/titanium (Ti) films showed relatively excellent chemical stability after exposure to H2SO4 solution with pH 3 at 80 C.

  12. Effect of Plasma Nitriding and Nitrocarburizing on HVOF-Sprayed Stainless Steel Coatings

    NASA Astrophysics Data System (ADS)

    Park, Gayoung; Bae, Gyuyeol; Moon, Kyungil; Lee, Changhee

    2013-12-01

    In this work, the effects of plasma nitriding (PN) and nitrocarburizing on HVOF-sprayed stainless steel nitride layers were investigated. 316 (austenitic), 17-4PH (precipitation hardening), and 410 (martensitic) stainless steels were plasma-nitrided and nitrocarburized using a N2 + H2 gas mixture and the gas mixture containing C2H2, respectively, at 550 C. The results showed that the PN and nitrocarburizing produced a relatively thick nitrided layer consisting of a compound layer and an adjacent nitrogen diffusion layer depending on the crystal structures of the HVOF-sprayed stainless steel coatings. Also, the diffusion depth of nitrogen increased when a small amount of C2H2 (plasma nitrocarburizing process) was added. The PN and nitrocarburizing resulted in not only an increase of the surface hardness, but also improvement of the load bearing capacity of the HVOF-sprayed stainless steel coatings because of the formation of CrN, Fe3N, and Fe4N phases. Also, the plasma-nitrocarburized HVOF-sprayed 410 stainless steel had a superior surface microhardness and load bearing capacity due to the formation of Cr23C6 on the surface.

  13. Effect of different environmental parameters on pitting behavior of AISI type 316L stainless steel: Experimental studies and neural network modeling

    Microsoft Academic Search

    K. V. S. Ramana; T. Anita; Sumantra Mandal; S. Kaliappan; H. Shaikh; P. V. Sivaprasad; R. K. Dayal; H. S. Khatak

    2009-01-01

    AISI type 316L stainless steel was subjected to electrochemical polarization tests in an aqueous environment of varying chloride ion concentration (17,50070,000ppm), pH (1.235.0) and temperature (298333K). Values of critical pitting potentials (Epit) were determined from the polarization tests. Increasing concentration and temperature, and decreasing pH were found to decrease the Epit. Eighty values of Epit, at different chloride concentrations, pH

  14. pH

    NSDL National Science Digital Library

    This lab activity is designed to teach students how to test for pH and understand its relationship to them and their environment. They will learn what pH is, draw and label a pH scale, measure the pH of various items, and explain why it's important to understand pH, for example, the danger presented by substances having very high or low pH.

  15. Friction Drilling of Stainless Steels Pipes

    Microsoft Academic Search

    A. Fernndez; L. N. Lopez de Lacalle; A. Lamikiz

    2011-01-01

    This work describes the experimental study of the friction drilling process in stainless steel by means of an optimization of the machining conditions. For such purpose austenitic stainless steel with different thicknesses were analyzed through controlled tests at different rotation speeds and feed rates. On one hand, the torque and the thrust force were computed and monitorized. On the other

  16. PRECIPITATION HARDENING P\\/M STAINLESS STEELS

    Microsoft Academic Search

    Chris Schade; Pat Stears; Alan Lawley; Roger Doherty

    Applications requiring high strength stainless steels are growing rapidally. Precipitation- hardening stainless steels have seen limited use in powder metallurgy despite their high strength. Strengthening of these alloys is achieved by adding elements such as copper and niobium, which form intermetallic precipitates during aging. The precipitation-hardening grades exhibit corrosion resistance levels comparable with those of the chromium-nickel (300 series) grades.

  17. The energy benefit of stainless steel recycling

    Microsoft Academic Search

    Jeremiah Johnson; B. K. Reck; T. Wang; T. E. Graedel

    2008-01-01

    The energy used to produce austenitic stainless steel was quantified throughout its entire life cycle for three scenarios: (1) current global operations, (2) 100% recycling, and (3) use of only virgin materials. Data are representative of global average operations in the early 2000s. The primary energy requirements to produce 1 metric ton of austenitic stainless steel (with assumed metals concentrations

  18. Corrosionerosion behavior of TiN-coated stainless steels in aqueous slurries

    Microsoft Academic Search

    Diana Lpez; Carlos Snchez; Alejandro Toro

    2005-01-01

    The corrosionerosion resistance of TiN-coated AISI 304 and AISI 420 stainless steels in aqueous slurries was studied. TiN films with a thickness of 0.6?m were obtained by using the pulsed-arc plasma-assisted physical vapour deposition technique. The corrosionerosion experiments were performed in a test machine in which the impingement velocity, impact angle, concentration of solids and pH of the solution were

  19. Influence of friction on the local mechanical and electrochemical behaviour of duplex stainless steels

    Microsoft Academic Search

    V. Vignal; N. Mary; P. Ponthiaux; F. Wenger

    2006-01-01

    The electrochemical behaviour of ferritic and austenitic phases in duplex stainless steel (UNS S32304) and the modifications induced by straining during sliding were studied by potentiodynamic polarisation curves determined at the microscale in a 1M NaCl (pH 3) solution, using an electrochemical microcell. The mechanical properties and stress state of each phase were determined by microhardness and X-ray microdiffraction measurements,

  20. Effects of alloy and solution chemistry on the fracture of passive films on austenitic stainless steel

    Microsoft Academic Search

    A. Alamr; D. F. Bahr; Michael Jacroux

    2006-01-01

    The Taguchi analysis method was used to simultaneously study the effects of alloy chemistry, pH, and halide ion concentrations on the fracture of electrochemically grown passive films using a nanoindentation technique. Three austenitic stainless steels, 304L, 316L, and 904L were potentiostatically polarized in hydrochloric acid solutions. The fracture load was dominated primarily by alloy chemistry. Passive films mechanically weaken as

  1. Acoustic emission during the electrochemical corrosion of 304 stainless steel in H 2SO 4 solutions

    Microsoft Academic Search

    Jian Xu; Xinqiang Wu; En-Hou Han

    2011-01-01

    Acoustic emission (AE) behaviour during the electrochemical corrosion of 304 stainless steel (304SS) in H2SO4 solutions was studied. AE signals which related to transpassive dissolution are detected in solutions with low pH, and are very slightly influenced by current density and pre-strain. During hydrogen bubble evolution, a weak correlation exists between the AE signal amplitude and the hydrogen bubble diameter.

  2. Improvement of the forgability of 17-4 precipitation hardening stainless steel by ausforming

    Microsoft Academic Search

    Sachihiro Isogawa; Hiroaki Yoshida; Yuzo Hosoi; Yasuhisa Tozawa

    1998-01-01

    The ausforming process for 17-4 precipitation hardening (17-4PH) stainless steel is compared with the conventional warm-forging process, from the point of both the forgeability and the properties of the forged material. The forgeability is evaluated by upsetting, forward rod extrusion and backward can extrusion. The forging force required in ausforming is about half that required in conventional warm-forging: it especially

  3. Effect of ion implantation species on the tribological response of stainless steel surfaces

    Microsoft Academic Search

    L. E. Pope; S. T. Picraux; D. M. Follstaedt; J. A. Knapp; F. G. Yost

    1985-01-01

    The friction and wear properties of 304 and 155 PH stainless steels which were ion implanted with P and with P plus C have\\u000a been examined and are compared with the properties of the same steels implanted with N and with Ti plus C. While benefits\\u000a are obtained with the P and the P plus C implantation treatments, the N

  4. Friction and wear of stainless steels implanted with Ti and C

    Microsoft Academic Search

    F. G. Yost; L. E. Pope; D. M. Follstaedt; J. A. Knapp; S. T. Picraux

    1981-01-01

    Friction and wear tests were completed on Fe and stainless steels of the type 304, 15-5 pH, Nitronic 60, and 440C implanted with Ti and C. Samples were mechanically polished prior to ion implantation to fluences of 2 x 10¹⁷ Ti\\/cm² (90 to 180 keV) and 2 x 10¹⁷ C\\/cm² (30 keV); the implantation profiles of the two elements overlapped

  5. Crevice corrosion of duplex stainless steel in simulated sour gas environments

    Microsoft Academic Search

    S. Azuma; H. Tsuge; T. Kudo; T. Moroishi

    1987-01-01

    The crevice corrosion behavior of 22%Cr duplex stainless steel, which has come into wide use for its high strength and SCC resistance, was investigated in the simulated sour gas conditions below 80°C. The crevice corrosion is accelerated by following factors; partial pressure of H2S, temperature, decreasing pH of the test solution, and the addition of elemental sulfur. Compared the duplex

  6. Corrosionerosion of nitrogen bearing martensitic stainless steels in seawaterquartz slurry

    Microsoft Academic Search

    A. Toro; A. Sinatora; D. K. Tanaka; A. P. Tschiptschin

    2001-01-01

    AISI 410S stainless steel was nitrided at 1473K in N2 atmosphere, direct quenched and tempered at temperatures between 473 and 873K. Martensitic cases with circa 0.52wt.%N at the surface were obtained. Corrosionerosion tests were carried out in slurries composed by quartz particles and tap or substitute ocean water. The concentration of solids, the impact angle and the pH of solution

  7. An acoustic emission technique for monitoring pitting corrosion of austenitic stainless steels

    Microsoft Academic Search

    H. Mazille; R. Rothea; C. Tronel

    1995-01-01

    An acoustic emission (AE) technique was used to detect and study the development of pitting corrosion on AISI 316L austenitic stainless steel in laboratory experiments. Tests were conducted at room temperature in 3% NaCl solution acidified to pH 2, at the free corrosion potential or with applied anodic polarization. It appears that AE signals were easily detected during pitting corrosion

  8. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    PubMed Central

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets titanium, self-ligating stainless steel, and conventional stainless steel using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. Results and Conclusion: We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA), Student's t test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional rsistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets. PMID:23066253

  9. Interaction between stainless steel and plutonium metal

    SciTech Connect

    Dunwoody, John T [Los Alamos National Laboratory; Mason, Richard E [Los Alamos National Laboratory; Freibert, Franz J [Los Alamos National Laboratory; Willson, Stephen P [Los Alamos National Laboratory; Veirs, Douglas K [Los Alamos National Laboratory; Worl, Laura A [Los Alamos National Laboratory; Archuleta, Alonso [Los Alamos National Laboratory; Conger, Donald J [Los Alamos National Laboratory

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  10. Development of New Stainless Steel

    SciTech Connect

    Robert F. Buck

    2005-08-30

    A new family of innovative martensitic stainless steels, 521-A, 521-B, and 521-C has been developed by Advanced Steel Technology, LLC (Trafford, PA) as high strength fastener (bolt) materials for use at moderate temperatures in turbine engines, including steam turbines, gas turbines, and aircraft engines. The primary objective of the development program was to create a martensitic stainless steel with high strength at moderate temperatures, and which could replace the expensive nickel-based superalloy IN 718 in some fasteners applications. A secondary objective was to replace conventional 12Cr steels such as AISI 422 used as blades, buckets and shafts that operate at intermediate temperatures in turbine engines with stronger steel. The composition of the new alloys was specifically designed to produce excellent mechanical properties while integrating heat treatment steps into production to reduce energy consumption during manufacturing. As a result, production costs and energy consumption during production of rolled bar products is significantly lower than conventional materials. Successful commercialization of the new alloys would permit the installed cost of certain turbine engines to be reduced without sacrificing high availability or operational flexibility, thereby enhancing the global competitiveness of U.S. turbine engine manufacturers. Moreover, the domestic specialty steel industry would also benefit through increased productivity and reduced operating costs, while increasing their share of the international market for turbine engine fasteners, blades, buckets and shafts.

  11. Behavior of type 304 and type 316 austenitic stainless in 55% lithium bromide heavy brine environments

    SciTech Connect

    Itzhak, D.; Elias, O. (Ben-Gurion Univ., Beer-Sheva (Israel). Dept. of Materials Engineering)

    1994-02-01

    Cylindrical tensile specimens of AISI type 304 (UNS S30400) and type 316 (UNS S31600) stainless steels (SS) were tested under constant-load conditions in 55% lithium bromide (LiBr) heavy brines at temperatures of 120 C and 140 C. Elongation and open-circuit potential (OCP) were recorded during the tensile test. Potentiodynamic polarization measurements were conducted, and the failed surface fractures were examined by scanning electron microscopy. The tested SS were subjected to stress corrosion under the test environments. Sensitivity was affected strongly by pH values. In LiBr brine of pH = 11.6, the passivation processes were more effective than in brine of pH = 6 [approximately] 8. Because of effective passivation behavior in brine of pH = 11.6, lower values of [delta]l[sub 0] were measured, indicating lower dislocation relaxation processes and high resistance to stress corrosion cracking.

  12. LOCAL BUCKLING OF COLD-FORMED STAINLESS STEEL SECTIONS

    Microsoft Academic Search

    K J R Rasmussen; P Bezkorovainy; M R Bambach

    Research at the University of Sydney, in the stainless steel area has for the last three years concentrated on the local buckling strength of stainless steel plates with application to cold-formed sections. The research has encompassed tests on single stainless steel plates, and the finite element modelling of stainless steel plates. Research was also carried out to determine the stress-strain

  13. A porous stainless steel membrane system for extraterrestrial crop production.

    PubMed

    Koontz, H V; Prince, R P; Berry, W L

    1990-06-01

    A system was developed in which nutrient flow to plant roots is controlled by a thin (0.98 or 1.18 mm) porous (0.2 or 0.5 microns) stainless steel sheet membrane. The flow of nutrient solution through the membrane is controlled by adjusting the relative negative pressure on the nutrient solution side of the membrane. Thus, the nutrient solution is contained by the membrane and cannot escape from the compartment even under microgravity conditions if the appropriate pressure gradient across the membrane is maintained. Plant roots grow directly on the top surface of the membrane and pull the nutrient solution through this membrane interface. The volume of nutrient solution required by this system for plant growth is relatively small, since the plenum, which contains the nutrient solution in contact with the membrane, needs only to be of sufficient size to provide for uniform flow to all parts of the membrane. Solution not passing through the membrane to the root zone is recirculated through a reservoir where pH and nutrient levels are controlled. The size of the solution reservoir depends on the sophistication of the replenishment system. The roots on the surface of the membrane are covered with a polyethylene film (white on top, black on bottom) to maintain a high relative humidity and also limit light to prevent algal growth. Seeds are sown directly on the stainless steel membrane under the holes in the polyethylene film that allow a pathway for the shoots. PMID:11537562

  14. Mechanism of dissimilar metal crevice corrosion of superferritic stainless steels

    SciTech Connect

    Salamat, G.; Juhl, G.A.; Kelly, R.G. [Univ. of Virginia, Charlottesville, VA (United States)

    1995-11-01

    Superferritic stainless steels (SS) can suffer from dissimilar metal crevice (DMC) corrosion when part of a crevice with certain other stainless alloys. For example, UNS S44735 is attacked when part of a crevice with type 316 SS (UNS S30400). To understand this phenomenon better, solutions which form inside such crevices were collected and analyzed with ion chromatography and capillary electrophoresis for their metal ion content. These analyses provided the data required to design bulk solutions for electrochemical kinetics measurements. Electrochemical measurements in these simulated crevice solutions were compared to measurements made in simple hydrochloric acid solutions. The simulated crevice solutions were much more aggressive toward the materials than the simple HCl solutions. The superferritic SS was depassivated more easily in the simulated crevice solutions and exhibited a much larger active-to-passive transition in these solutions. In HCl solutions of the same pH, the superferritic SS passivated quite easily and could be depassivated only with great difficulty. These results were used to rationalize the observations of DMC corrosion of UNS S44735 when part of a crevice with type 316 SS and the failure of electrochemical measurements in simple HCl solutions to predict this attack. The origin of the specificity of the alloys that cause DMC corrosion of UNSS44735 was explained in terms of the effect of alloyed molybdenum on electrode kinetics of these alloys in the critical crevice solution. The roles of ohmic drop and chloride ion concentration on the initiation and propagation of DMC corrosion also were considered.

  15. 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).

  16. Tritiated Water Interaction with Stainless Steel

    SciTech Connect

    Glen R. Longhurst

    2007-05-01

    Experiments conducted to study tritium permeation of stainless steel at ambient and elevated temperatures revealed that HT converts relatively quickly to HTO. Further, the HTO partial pressure contributes essentially equally with elemental tritium gas in driving permeation through the stainless steel. Such permeation appears to be due to dissociation of the water molecule on the hot stainless steel surface. There is an equilibrium concentration of HTO vapor above adsorbed gas on the walls of the experimental apparatus evident from freezing transients. The uptake process of tritium from the carrier gas involves both surface adsorption and isotopic exchange with surface bound water.

  17. Phase transformations in welded supermartensitic stainless steels

    E-print Network

    Carrouge, Dominique

    (table 1.6), but with only 0.01 wt% C, supermartensitic stainless steel martensite is relatively soft. Martensite hardness is also claimed to be affected by the presence of nitrogen. In this respect, 1.3 Phases present and mechanical properties 17... . Bhadeshia and P. Woollin, Microstructural change in high temperature heat-affected zone of low carbon weldable 13 %Cr martensitic stainless steels, Proceedings of the Stainless Steel World conference 2002 (Houston, Texas, USA), 61-67. P. Woollin and D...

  18. 76 FR 34964 - Stainless Steel Bar From India: Partial Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ...Venus, Ambica Steels Limited (``Ambica''), Atlas Stainless Corporation (``Atlas Stainless''), Bhansali Bright Bars Pvt. Ltd...duty administrative review, covering Ambica, Atlas Stainless, Bhansali, Chandan, Facor,...

  19. Advantages in solution nitriding of stainless steels

    Microsoft Academic Search

    H. Berns

    2007-01-01

    Stainless steels are case-hardened with nitrogen instead of carbon to improve their resistance to pitting, wear, and cavitation.\\u000a The new heat treatment is industrially available and has gained numerous applications.

  20. Hydrogen compatibility handbook for stainless steels

    SciTech Connect

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  1. Copper\\/Stainless Steel Polyhelix Magnets

    Microsoft Academic Search

    F. Lecouturier; J. Billette; J. Beard; F. Debray; N. Ferreira; J. M. Tudela; G. Rikken; P. Frings

    2012-01-01

    The LNCMI has been involved since many years in the research and development of copper\\/stainless steel (Cu\\/SS) macrocomposite conductors for wire wound pulsed field magnets, generating magnetic fields up to 80 Tesla. The mechanical and electrical properties are adjusted to the magnet requirements by selecting the area fraction of the stainless steel reinforcement and the work-hardening state at the end

  2. High-Power Diode Laser-Treated 13Cr4Ni Stainless Steel for Hydro Turbines

    NASA Astrophysics Data System (ADS)

    Mann, B. S.

    2014-06-01

    The cast martensitic chromium nickel stainless steels such as 13Cr4Ni, 16Cr5Ni, and 17Cr4Ni PH have found wide application in hydro turbines. These steels have adequate corrosion resistance with good mechanical properties because of chromium content of more than 12%. The 13Cr4Ni stainless steel is most widely used among these steels; however, lacks silt, cavitation, and water impingement erosion resistances (SER, CER, and WIER). This article deals with characterizing 13Cr4Ni stainless steel for silt, cavitation, and water impingement erosion; and studying its improved SER, CER, and WIER behavior after high-power diode laser (HPDL) surface treatment. The WIER and CER have improved significantly after laser treatment, whereas there is a marginal improvement in SER. The main reason for improved WIER and CER is due to its increased surface hardness and formation of fine-grained microstructure after HPDL surface treatment. CER and WIER of HPDL-treated 13Cr4Ni stainless steel samples have been evaluated as per ASTM G32-2003 and ASTM G73-1978, respectively; and these were correlated with microstructure and mechanical properties such as ultimate tensile strength, modified ultimate resilience, and microhardness. The erosion damage mechanism, compared on the basis of scanning electron micrographs and mechanical properties, is discussed and reported in this article.

  3. Stress corrosion cracking of duplex stainless steels in caustic solutions

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Ananya

    Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion cracking of duplex stainless steels in chloride solution has been investigated and well documented in the literature but the SCC mechanisms for DSS in caustic solutions were not known. Microstructural changes during fabrication processes affect the overall SCC susceptibility of these steels in caustic solutions. Other environmental factors, like pH of the solution, temperature, and resulting electrochemical potential also influence the SCC susceptibility of duplex stainless steels. In this study, the role of material and environmental parameters on corrosion and stress corrosion cracking of duplex stainless steels in caustic solutions were investigated. Changes in the DSS microstructure by different annealing and aging treatments were characterized in terms of changes in the ratio of austenite and ferrite phases, phase morphology and intermetallic precipitation using optical micrography, SEM, EDS, XRD, nano-indentation and microhardness methods. These samples were then tested for general and localized corrosion susceptibility and SCC to understand the underlying mechanisms of crack initiation and propagation in DSS in the above-mentioned environments. Results showed that the austenite phase in the DSS is more susceptible to crack initiation and propagation in caustic solutions, which is different from that in the low pH chloride environment where the ferrite phase is the more susceptible phase. This study also showed that microstructural changes in duplex stainless steels due to different heat treatments could affect their SCC susceptibility. Annealed and water quenched specimens were found to be immune to SCC in caustic environment. Aging treatment at 800C gave rise to sigma and chi precipitates in the DSS. However, these sigma and chi precipitates, known to initiate cracking in DSS in chloride environment did not cause any cracking of DSS in caustic solutions. Aging of DSS at 475C had resulted in '475C embrittlement' and caused cracks to initiate in the ferrite phase. This was in contrast to the cracks initiating in the austenite phase in the as-received DSS. Alloy composition and microstructure of DSS as well as solution composition (dissolved ionic species) was also found to affect the electrochemical behavior and passivation of DSS which in turn plays a major role in stress corrosion crack initiation and propagation. Corrosion rates and SCC susceptibility of DSS was found to increase with addition of sulfide to caustic solutions. Corrosion films on DSS, characterized using XRD and X-ray photoelectron spectroscopy, indicated that the metal sulfide compounds were formed along with oxides at the metal surface in the presence of sulfide containing caustic environments. These metal sulfide containing passive films are unstable and hence breaks down under mechanical straining, leading to SCC initiations. The overall results from this study helped in understanding the mechanism of SCC in caustic solutions. Favorable slip systems in the austenite phase of DSS favors slip-induced local film damage thereby initiating a stress corrosion crack. Repeated film repassivation and breaking, followed by crack tip dissolution results in crack propagation in the austenite phase of DSS alloys. Result from this study will have a significant impact in terms of identifying the alloy compositions, fabrication processes, microstructures, and environmental conditions that may be avoided to mitigate corrosion and stress corrosion cracking of DSS in caustic solutions.

  4. 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.

  5. Corrosion Resistance of Amorphous Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 coating - a new criticality-controlled material

    SciTech Connect

    Farmer, J C; Choi, J S; Saw, C K; Rebak, R; Day, S D; Lian, T; Hailey, P; Payer, J H; Branagan, D J; Aprigliano, L F

    2007-03-28

    An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initially produced, large quantities (several tons) of gas atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent nuclear fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. Modes and rates of corrosion have been determined in various relevant environments, and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved.

  6. Long-Term Corrosion Tests of Prototypical SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) Coatings

    SciTech Connect

    Farmer, J C; Choi, J S; Saw, C K; Rebak, R H; Day, S D; Lian, T; Hailey, P D; Payer, J H; Branagan, D J; Aprigliano, L F

    2007-05-10

    An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initially produced, large quantities (several tons) of gas atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent nuclear fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. The modes and rates of corrosion have been determined in the various environments, and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved.

  7. The abrasion-wear resistance of arc sprayed stainless steel and composite stainless steel coatings

    SciTech Connect

    Dallaire, S.; Legoux, J.G.; Levert, H. [National Research Council Canada, Boucherville, Quebec (Canada)

    1994-12-31

    Stainless steels are often used to palliate wear problems in various industries. Though they are not wear resistant, they have been used to a limited extent in applications involving both corrosive and abrasive/erosive environments. The protection of industrial components by arc sprayed stainless steel composite coatings could be considered very attractive provided these coatings offer a better wear protection than bulk stainless steel. The wear resistance of stainless steel and composite stainless steel-titanium boride coatings arc sprayed with air and argon was evaluated following the ASTM G-65 Abrasion Wear Test procedures. Wear volume loss measurements show that stainless steel coatings arc sprayed with air were slightly more resistant than bulk stainless steel while those sprayed with argon were slightly less resistant. The abrasion wear resistance of composite stainless steel-titanium diboride coatings is by two or four times beyond the wear resistance of bulk stainless steel depending upon the core wire constitution and the type of gas used for spraying. Microstructural analysis of coatings, microhardness measurements of sprayed lamellae and optical profilometry were used to characterize coatings and wear damages. Spraying with air instead of argon produced much more small particles. These particles, being removed from the metal sheath surface, are individually sprayed without diluting the concentration hard phases within cores. It results in coatings that contain large lamellae with hardnesses sufficient to withstand abrasion. By considering both the wire constitution and the spraying conditions, it was found possible to fabricate composite stainless steel coatings that show a 400% increase in wear resistance over bulk stainless steel.

  8. High Mn austenitic stainless steel

    DOEpatents

    Yamamoto, Yukinori (Oak Ridge, TN) [Oak Ridge, TN; Santella, Michael L (Knoxville, TN) [Knoxville, TN; Brady, Michael P (Oak Ridge, TN) [Oak Ridge, TN; Maziasz, Philip J (Oak Ridge, TN) [Oak Ridge, TN; Liu, Chain-tsuan (Knoxville, TN) [Knoxville, TN

    2010-07-13

    An austenitic stainless steel alloy includes, in weight percent: >4 to 15 Mn; 8 to 15 Ni; 14 to 16 Cr; 2.4 to 3 Al; 0.4 to 1 total of at least one of Nb and Ta; 0.05 to 0.2 C; 0.01 to 0.02 B; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1W; up to 3 Cu; up to 1 Si; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale including alumina, nanometer scale sized particles distributed throughout the microstructure, the particles including at least one of NbC and TaC, and a stable essentially single phase FCC austenitic matrix microstructure that is essentially delta-ferrite-free and essentially BCC-phase-free.

  9. A model for prediction of possibility of localized corrosion attack of stainless steels

    SciTech Connect

    Hakkarainen, T.J.

    1996-10-01

    Empirical or semi-empirical relations were developed to express the dependence of the possibility (probability) of localized corrosion attack of various stainless steels on environmental factors. Only chloride induced attack within the range 0--100 C (32--212 F) is considered. The environmental variables considered include temperature, pH, chloride content, sulfate content, presence of oxidizing agents, crevices and deposits, flow rate and possibility of concentration of solution by evaporation. Common mathematical operations are used to formulate the trends into equations. Examples of the predictions of the model are given for type AISI 316 stainless steel in two environments: Baltic Sea water at 25 C and a solution containing 300 mg/l of chloride ions at 70 C.

  10. 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.

  11. Superplastic forming of stainless steel automotive components

    SciTech Connect

    Bridges, B. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN (United States); Elmer, J. [Lawrence Livermore National Lab., CA (United States); Carol, L. [AC Delco Systems World Headquarters, Flint, MI (United States). USCAR Low Emissions Technology Research and Development Partnership

    1997-02-06

    Exhaust emission standards are governmentally controlled standards, which are increasingly stringent, forcing alternate strategies to meet these standards. One approach to improve the efficiency of the exhaust emission equipment is to decrease the time required to get the catalytic converter to optimum operating temperature. To accomplish this, automotive manufacturers are using double wall stainless steel exhaust manifolds to reduce heat loss of the exhaust gases to the converter. The current method to manufacture double wall stainless steel exhaust components is to use a low-cost alloy with good forming properties and extensively form, cut, assemble, and weld the pieces. Superplastic forming (SPF) technology along with alloy improvements has potential at making this process more cost effective. Lockheed Martin Energy Systems (LMES), Lawrence Livermore National Laboratory (LLNL) and USCAR Low Emission Partnership (LEP) worked under a Cooperative Research And Development Agreement (CRADA) to evaluate material properties, SPF behavior, and welding behavior of duplex stainless steel alloy for automotive component manufacturing. Battelle Pacific Northwest National Laboratory (PNNL) has a separate CRADA with the LEP to use SPF technology to manufacture a double wall stainless steel exhaust component. As a team these CRADAs developed and demonstrated a technical plan to accomplish making double wall stainless steel exhaust manifolds.

  12. pH Calculation

    NSDL National Science Digital Library

    Johansson, Stig

    This pair of pH calculation programs serves as an excellent tool for anyone wishing to calculate the pH of a solution containing multiple acids and bases. These programs allow practitioners to predict the pH of simple and complex acid/base solutions and buffers. They may be downloaded free of charge via the website. Users are encouraged to carefully read the guides provided by the author.

  13. 21 CFR 872.3350 - Gold or stainless steel cusp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices 872.3350 Gold or stainless steel cusp. (a) Identification. A gold or stainless steel cusp...

  14. Quantification of phase transformation in stainless steel 301LN sheets

    E-print Network

    Beese, Allison M

    2008-01-01

    This thesis investigates the large deformation behavior of stainless steel 301LN cold-rolled sheets which is largely governed by the initial anisotropy combined with the phase transformation during deformation. Stainless ...

  15. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices 878.4495 Stainless steel suture. (a) Identification. A stainless steel...

  16. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices 878.4495 Stainless steel suture. (a) Identification. A stainless steel...

  17. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices 878.4495 Stainless steel suture. (a) Identification. A stainless steel...

  18. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices 878.4495 Stainless steel suture. (a) Identification. A stainless steel...

  19. Monitoring pitting corrosion of AISI 316L austenitic stainless steel by acoustic emission technique: Choice of representative acoustic parameters

    Microsoft Academic Search

    M. Fregonese; H. Idrissi; H. Mazille; L. Renaud; Y. Cetre

    2001-01-01

    This experimental work was aimed at investigating the monitoring of pitting corrosion by the acoustic emission (AE) technique, for pits developed by potentiostatic or galvanostatic polarization on two types of 316L austenitic stainless steels, in a 3% NaCl solution acidified to pH 2. The study of the evolution of AE global activity during the test showed the existence of a

  20. 21 CFR 878.4495 - Stainless steel suture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    21 Food and Drugs 8 2010-04-01 2010-04-01 false Stainless steel suture...unneedled nonabsorbable surgical suture composed of 316L stainless steel, in USP sizes 12-0 through 10, or a substantially equivalent stainless...

  1. 77 FR 64545 - Drawn Stainless Steel Sinks From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ...Register Volume 77, Number 204 (Monday, October...Final)] Drawn Stainless Steel Sinks From China Scheduling...corners. Drawn stainless steel sinks are available in...may be described in a number of ways including flush...countertop). Stainless steel sinks with multiple...

  2. Evaluation of the stress corrosion behavior of selected stainless steels

    Microsoft Academic Search

    Dorning; R. E. II

    1983-01-01

    The objective of this investigation was to determine the stress corrosion behavior of selected stainless steels in several fluorinating environments. The possibility of stress corrosion cracking or pitting which could substantially reduce the serviceability of the stainless steels was the primary concern. Laboratory testing indicated that stress corrosion cracking or other forms of localized attack of the austenitic stainless steels

  3. INTERACTION OF WHEY PROTEIN WITH MODIFIED STAINLESS STEEL SURFACES

    Microsoft Academic Search

    S. S. Premathilaka; M. M. Hyland; X. D. Chen; L. R. Watkins; B. Bansal

    2008-01-01

    Modified stainless steel surfaces were fouled with whey protein solutions to study the deposition mechanisms and the effects of surface modification. Stainless steel samples were coated with diamond-like carbon (DLC) and titanium nitride (TiN). These surfaces are expected to present different surface chemistries to stainless steel in terms of their functional groups and hydrophobic or hydrophilic nature. Thus, it is

  4. Friction Drilling of Stainless Steels Pipes

    NASA Astrophysics Data System (ADS)

    Fernndez, A.; Lopez de Lacalle, L. N.; Lamikiz, A.

    2011-01-01

    This work describes the experimental study of the friction drilling process in stainless steel by means of an optimization of the machining conditions. For such purpose austenitic stainless steel with different thicknesses were analyzed through controlled tests at different rotation speeds and feed rates. On one hand, the torque and the thrust force were computed and monitorized. On the other hand, the dimensional tolerances of the holes were evaluated, mainly the accuracy of the hole diameter and the burr thickness at different depths. Another topic of interest inherent to this special technique is the temperature level reached during the friction process which is crucial when it comes to development of microstructural transformations.

  5. Embrittlement of austenitic stainless steel welds

    SciTech Connect

    David, S.A.; Vitek, J.M.; Alexander, D.J.

    1995-06-01

    To prevent hot-cracking, austenitic stainless steel welds generally contain a small percent of delta ferrite. Although ferrite has been found to effectively prevent hot-cracking, it can lead to embrittlement of welds when exposed to elevated temperatures. The aging behavior of type-308 stainless steel weld has been examined over a range of temperatures 475--850 C for times up to 10,000 hrs. Upon aging, and depending on the temperature range, the unstable ferrite may undergo a variety of solid state transformations. These phase changes creep-rupture and Charpy impact properties.

  6. Stainless Steel Microstructure and Mechanical Properties Evaluation

    SciTech Connect

    Switzner, Nathan T

    2010-06-01

    A nitrogen strengthened 21-6-9 stainless steel plate was spinformed into hemispherical test shapes. A battery of laboratory tests was used to characterize the hemispheres. The laboratory tests show that near the pole (axis) of a spinformed hemisphere the yield strength is the lowest because this area endures the least cold-work strengthening, i.e., the least deformation. The characterization indicated that stress-relief annealing spinformed stainless steel hemispheres does not degrade mechanical properties. Stress-relief annealing reduces residual stresses while maintaining relatively high mechanical properties. Full annealing completely eliminates residual stresses, but reduces yield strength by about 30%.

  7. Study of passive films formed on AISI 304 stainless steel by impedance measurements and photoelectrochemistry

    SciTech Connect

    Simoes, A.M.P.; Ferreiro, M.G.S. (Dept. de Engenharia Quimica, Instituto Superior Tecnico, 1096 Lisboa Codex (PT)); Rondot, B.; Belo, M. (Centre National de la Recherche Scientifique, 94 - Vitry-sur-Seine (France). Centre d'Etudes de Chimie Metallurgique)

    1990-01-01

    Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe{sup 2 +} on tetrahedral sites.

  8. Materials data handbooks on stainless steels

    NASA Technical Reports Server (NTRS)

    Muraca, R. F.; Whittick, J. S.

    1973-01-01

    Two handbooks which summarize latest available data have been published. Two types of stainless steels, alloy A-286 and Type 301, are described. Each handbook is divided into twelve chapters. Scope of information presented includes physical- and mechanical-property data at cryogenic, ambient, and elevated temperatures.

  9. Forming "dynamic" membranes on stainless steel

    NASA Technical Reports Server (NTRS)

    Brandon, C. A.; Gaddis, J. L.

    1979-01-01

    "Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

  10. Failure of stainless steel water pump couplings

    Microsoft Academic Search

    C. R Gagg

    2001-01-01

    A number of lift pump couplings, that had been manufactured in India to a long established design, were submitted to determine the reasons for their in-service failure. Past history for this type of water pump would suggest that failures of this artefact were a very rare occurrence. However, failures were being encountered with a particular type of stainless steel coupling

  11. Materials data handbook: Stainless steel type 301

    NASA Technical Reports Server (NTRS)

    Muraca, R. F.; Whittick, J. S.

    1972-01-01

    A summary of the materials property information for stainless steel type 301 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

  12. Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

    NASA Astrophysics Data System (ADS)

    Zhang, Zongyang; Cheng, Xingguo; Leng, Yi; Cao, Gang; Liu, Sheng

    2014-05-01

    In this paper, a steel pressure sensor using strain gages bonded on a 17-4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17-4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors.

  13. Weld microstructure development and properties of precipitation-strengthened martensitic stainless steels

    SciTech Connect

    Brooks, J.A. (Sandia National Labs., Livermore, CA (United States)); Garrison, W.R. Jr. (Carnegie-Mellon Univ., Pittsburgh, PA (United States))

    1999-08-01

    The weld microstructural evolution, mechanical properties and solidification cracking susceptibility of three precipitation-strengthened martensitic stainless steels--PH 13-8 Mo, Custom 450 and 15-5 PH--were investigated. Liquid tin quenching of gas tungsten arc welds revealed that all three welds solidified as single-phase ferrite with a high degree of microsegregation. However, during further solidification and cooling almost complete homogenization occurred as a result of solid-state diffusion. The welds in all three alloys exhibited good resistance to solidification cracking and generally exhibited tensile and impact properties similar to those of the base metal. However, in almost all cases, the weld Charpy impact energies were somewhat less than those of the base metals. The cracking behavior and mechanical properties are discussed in terms of microstructural evolution.

  14. Biologics formulation factors affecting metal leachables from stainless steel.

    PubMed

    Zhou, Shuxia; Schneich, Christian; Singh, Satish K

    2011-03-01

    An area of increasing concern and scientific scrutiny is the potential contamination of drug products by leachables entering the product during manufacturing and storage. These contaminants may either have a direct safety impact on the patients or act indirectly through the alteration of the physicochemical properties of the product. In the case of biotherapeutics, trace amounts of metal contaminants can arise from various sources, but mainly from contact with stainless steel (ss). The effect of the various factors, buffer species, solution fill volume per unit contact surface area, metal chelators, and pH, on metal leachables from contact with ss over time were investigated individually. Three major metal leachables, iron, chromium, and nickel, were monitored by inductively coupled plasma-mass spectrometry because they are the major components of 316L ss. Iron was primarily used to evaluate the effect of each factor since it is the most abundant. It was observed that each studied factor exhibited its own effect on metal leachables from contact with ss. The effect of buffer species and pH exhibited temperature dependence over the studied temperature range. The metal leachables decreased with the increased fill volume (mL) per unit contact ss surface area (cm(2)) but a plateau was achieved at approximately 3 mL/cm(2). Metal chelators produced the strongest effect in facilitating metal leaching. In order to minimize the metal leachables and optimize biological product stability, each formulation factor must be evaluated for its impact, to balance its risk and benefit in achieving the target drug product shelf life. PMID:21360314

  15. Chromium and nickel aerosols in stainless steel manufacturing, grinding and welding

    Microsoft Academic Search

    MATTI KOPONEN; TOM GUSTAFSSON; PIRKKO-LIISA KALLIOMKI; LAURI PYY

    1981-01-01

    Composition, morphology and solubility of chromium and nickel in fumes from stainless steel manufacturing, based on ferrochrome, and in dusts from grinding of stainless steel, were studied. The results were compared with corresponding analyses of stainless steel welding fumes. In fumes from the melting of ferrochrome and stainless steel, as well as in dusts from the grinding of stainless steel,

  16. Radiation Effects in Stainless Steel and Tungsten for use in the ADS Spallation Neutron Source System

    Microsoft Academic Search

    Yongjun Xu; Zhiqiang Wang; Jiazheng Zhu; T. Minamisono; K. Matsuta; Yongnan Zheng; Dongmei Zhou; Guoji Xu; Enpeng Du; Youlin Fu; M. Fukuda; M. Mihara; Shengyun Zhu

    2003-01-01

    Radiation effects have been studied in modified 316L stainless steel and commercially available stainless steel and tungsten by the heavy ion irradiation simulation and positron lifetime techniques. The experimental results show that the radiation resistant property of stainless steel is much better than that of tungsten, and the modified 316L stainless steel is the best among them. The stainless steel

  17. 1. Abourashed E, El-Alfy A, Khan I, Walker L (2003). "Ephedra in perspective--a current review". Phytother Res 17 (7): 70312. 2. U.S. Food and Drug Administration. Ephedra is often seen in deserts. It has evergreen photosynthetic stems and leaves

    E-print Network

    , which have stimulating effects for the brain, heart rate, constriction of blood vessels and opening". Phytother Res 17 (7): 703­12. 2. U.S. Food and Drug Administration. Ephedra is often seen in deserts. It has

  18. Formability of type 304 stainless steel sheet

    SciTech Connect

    Coubrough, G.J. [EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant; Matlock, D.K.; VanTyne, C.J. [Colorado School of Mines, Golden, CO (United States)

    1992-09-01

    Punch-stretch tests to determine formability of type 304 stainless steel sheet were conducted using a hemispherical dome test. Sheets of 19.1 mm width and 177.8 mm width were stretched on a 101.6 mm diameter punch at punch rates between 0.042 to 2.12 mm/s with three lubricant systems: a mineral seal oil, thin polytetrafluoroethelyne sheet with mineral seal oil, and silicone rubber with mineral seal oil. The resulting strain distributions were measured and the amount of martensite was determined by magnetic means. Increasing lubricity resulted in more uniform strain distributions while increased punch rates tended to decrease both strain and transformation distributions. High forming limit values were related to the formation of high and uniformly distributed martensite volume fractions during deformation. The results of this study are interpreted with an analysis of the effects of strain and temperature on strain induced martensite formation in metastable austenitic stainless steels.

  19. Phase Transformation in Cast Superaustenitic Stainless Steels

    SciTech Connect

    Nathaniel Steven Lee Phillips

    2006-12-12

    Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3MCuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). The equilibrium microstructures, composed primarily of sigma and Laves within purely austenitic matrices, showed slow transformation kinetics. Factors that determine the extent of transformation, including diffusion, nucleation, and growth, are discussed.

  20. Creep cavitation in 304 stainless steel

    Microsoft Academic Search

    I. W. Chen; A. S. Argon

    1981-01-01

    Creep cavitation in 304 stainless steel at 0.5 T\\/sub m\\/ was investigated. Two specially developed techniques were used to study the nucleation and growth of grain-boundary cavities. It was found that cavities nucleated heterogeneously throughout the creep history and those observed were well in their growth stage. Comparison of these observations with the theory for cavity nucleation requires that a

  1. Corrosion of Stainless Steel During Acetate Production

    Microsoft Academic Search

    J. S. Qi; G. C. Lester

    1996-01-01

    Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CHCOOH under the process conditions commonly practiced in industry. The corrosive action of the

  2. Microstructure of Super-duplex Stainless Steels

    E-print Network

    Sharafi, Shahriar

    1993-12-07

    .2 Previous Work 77 5.3 Thermodynamic Assessment 78 Vll 5.4 High Temperature DSC Results 5.5 Microstructural Observations 5.6 Laser Welding. . . . . . . . 5.7 Conclusions . . . . . . . . . Chapter 6: Isothermal Heat Treatment and its Effect on the Ferrite... to solidify into a ferritic state using laser welds which traverse dissimilar metal junctions failed, confirming the mixed mode of solidifica- tion. These experiments lend further weight to the argument that super duplex stainless steels are highly unlikely...

  3. Welding high-molybdenum superaustenitic stainless steel

    SciTech Connect

    Ogawa, T. [Saitama Inst. of Technology, Ohsato-Okabe, Saitama (Japan). Dept. of Mechanical and Environmental Engineering; Koseki, T. [Nippon Steel Corp., Futtsu-Shintomi, Chiba (Japan). Steel Research Lab.

    1996-02-01

    A high-molybdenum, nitrogen-enriched, nickel-based filler metal was developed for welding superaustenitic stainless steels. The beneficial effects of high Ni content and nitrogen addition in reducing the solute microsegregation and the precipitation of intermetallic phases were used to design the filler alloy. The weld had a precipitate-free, fully austenitic microstructure and exhibited excellent mechanical properties, and reduced hot-cracking susceptibility and high-chloride pitting-corrosion resistance.

  4. The martensite phases in 304 stainless steel

    Microsoft Academic Search

    Pat L. Mangonon; Gareth Thomas

    1970-01-01

    A detailed analysis of martensite transformations in 18\\/8 (304) stainless steel, utilizing transmission electron microscopy\\u000a and diffraction in conjunction with X-ray and magnetization techniques, has established that the sequence of transformation\\u000a is ? ? ? ? ?. ? is a thermodynamically stable hcp phase whose formation is greatly enhanced as a result of plastic deformation.\\u000a Comparison with the ? ?

  5. Characteristics of Interdiffusion between 17-4 PH Steel and Nickel

    Microsoft Academic Search

    A. Laik; P. S. Gawde; K. Bhanumurthy; G. B. Kale

    2008-01-01

    The characteristics of interdiffusion between precipitation-hardened 17-4 PH grade stainless steel and nickel were studied\\u000a in the temperature range of 900C to 1100C, using diffusion couples of these two materials. The diffusion coefficients\\u000a of the major diffusing elements Fe, Ni, Cr, and Cu were evaluated for this multicomponent system. The diffusion paths plotted\\u000a on the Fe-Ni-Cr isotherm showed a flat

  6. Characteristics of Interdiffusion between 17-4 PH Steel and Nickel

    Microsoft Academic Search

    A. Laik; P. S. Gawde; K. Bhanumurthy; G. B. Kale

    2008-01-01

    The characteristics of interdiffusion between precipitation-hardened 17-4 PH grade stainless steel and nickel were studied in the temperature range of 900 C to 1100 C, using diffusion couples of these two materials. The diffusion coefficients of the major diffusing elements Fe, Ni, Cr, and Cu were evaluated for this multicomponent system. The diffusion paths plotted on the Fe-Ni-Cr isotherm showed

  7. Cast Stainless Steel Ferrite and Grain Structure

    SciTech Connect

    Ruud, Clayton O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Mathews, Royce; Diaz, Aaron A.; Anderson, Michael T.

    2012-09-01

    In-service inspection requirements dictate that piping welds in the primary pressure boundary of light-water reactors be subject to a volumetric examination based on the rules contained within the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI. The purpose of the inspection is the reliable detection and accurate sizing of service-induced degradation and/or material flaws introduced during fabrication. The volumetric inspection is usually carried out using ultrasonic testing (UT) methods. However, the varied metallurgical macrostructures and microstructures of cast austenitic stainless steel piping and fittings, including statically cast stainless steel and centrifugally cast stainless steel (CCSS), introduce significant variations in the propagation and attenuation of ultrasonic energy. These variations complicate interpretation of the UT responses and may compromise the reliability of UT inspection. A review of the literature indicated that a correlation may exist between the microstructure and the delta ferrite content of the casting alloy. This paper discusses the results of a recent study where the goal was to determine if a correlation existed between measured and/or calculated ferrite content and grain structure in CCSS pipe.

  8. Decontaminating and Melt Recycling Tritium Contaminated Stainless Steel

    SciTech Connect

    Clark, E.A.

    1995-04-03

    The Westinghouse Savannah River Company, Idaho National Engineering Laboratory, and several university and industrial partners are evaluating recycling radioactively contaminated stainless steel. The goal of this program is to recycle contaminated stainless steel scrap from US Department of Energy national defense facilities. There is a large quantity of stainless steel at the DOE Savannah River Site from retired heavy water moderated Nuclear material production reactors (for example heat exchangers and process water piping), that will be used in pilot studies of potential recycle processes. These parts are contaminated by fission products, activated species, and tritium generated by neutron irradiation of the primary reactor coolant, which is heavy (deuterated) water. This report reviews current understanding of tritium contamination of stainless steel and previous studies of decontaminating tritium exposed stainless steel. It also outlines stainless steel refining methods, and proposes recommendations based on this review.

  9. The pH Game

    NSDL National Science Digital Library

    This learning activity engages students in measurement of pH in water and soil samples, plants and other natural materials. By mixing different substances, they observe how pH changes, and become familiar with the pH of common household products. Through discussion, they learn how pH can be modified in the environment.

  10. pH Scale

    NSDL National Science Digital Library

    Wendy Adams

    2011-01-01

    In this online interactive simulation, learners will test the pH of liquids like coffee, spit, and soap to determine whether each is acidic, basic, or neutral. Learners will visualize the relative number of hydroxide ions and hydronium ions in a solution, and they can switch between logarithmic and linear scales. Learners will also investigate whether changing the volume or diluting with water affects the pH. They can experiment by designing their own liquids! This activity includes an online simulation, sample learning goals, a teacher's guide, and translations in over 30 languages.

  11. Hydrogen Induced Slow Crack Growth in Stable Austenitic Stainless Steels

    Microsoft Academic Search

    Wu-Yang Chu; Jing Yao; Chi-Mei Hsiao

    1984-01-01

    The behavior of hydrogen induced slow crack growth in type 310 and type 16-20-10 stable austenitic stainless steels along\\u000a with type 321 unstable austenitic stainless steel were investigated. It was found that slow crack growth could occur in all\\u000a three types of stainless steels, and the threshold values wereK\\u000a H\\/Kc = 0.55, 0.7, and 0.78 for type 321, 310, and

  12. Characterization of thermal aging of duplex stainless steel by SQUID

    SciTech Connect

    Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F. [Nuclear Fuel Industries, Ltd., Osaka (Japan)

    1995-08-01

    Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging.

  13. Stainless Steel Leaches Nickel and Chromium into Foods During Cooking

    PubMed Central

    Kamerud, Kristin L.; Hobbie, Kevin A.; Anderson, Kim A.

    2014-01-01

    Toxicological studies show that oral doses of nickel and chromium can cause cutaneous adverse reactions such as dermatitis. Additional dietary sources, such as leaching from stainless steel cookware during food preparation, are not well characterized. This study examined stainless steel grades, cooking time, repetitive cooking cycles, and multiple types of tomato sauces for their effects on nickel and chromium leaching. Trials included three types of stainless steels and a stainless steel saucepan; cooking times of 2 to 20 hours, ten consecutive cooking cycles, and four commercial tomato sauces. After a simulated cooking process, samples were analyzed by ICP-MS for Ni and Cr. After six hours of cooking, Ni and Cr concentrations in tomato sauce increased up to 26- and 7-fold respectively, depending on the grade of stainless steel. Longer cooking durations resulted in additional increases in metal leaching, where Ni concentrations increased 34 fold and Cr increased approximately 35 fold from sauces cooked without stainless steel. Cooking with new stainless steel resulted in the largest increases. Metal leaching decreases with sequential cooking cycles and stabilized after the sixth cooking cycle, though significant metal contributions to foods were still observed. The tenth cooking cycle, resulted in an average of 88 ?g of Ni and 86 ?g of Cr leached per 126 g serving of tomato sauce. Stainless steel cookware can be an overlooked source of nickel and chromium, where the contribution is dependent on stainless steel grade, cooking time, and cookware usage. PMID:23984718

  14. Stainless steel leaches nickel and chromium into foods during cooking.

    PubMed

    Kamerud, Kristin L; Hobbie, Kevin A; Anderson, Kim A

    2013-10-01

    Toxicological studies show that oral doses of nickel and chromium can cause cutaneous adverse reactions such as dermatitis. Additional dietary sources, such as leaching from stainless steel cookware during food preparation, are not well characterized. This study examined stainless steel grades, cooking time, repetitive cooking cycles, and multiple types of tomato sauces for their effects on nickel and chromium leaching. Trials included three types of stainless steels and a stainless steel saucepan, cooking times of 2-20 h, 10 consecutive cooking cycles, and four commercial tomato sauces. After a simulated cooking process, samples were analyzed by ICP-MS for Ni and Cr. After 6 h of cooking, Ni and Cr concentrations in tomato sauce increased up to 26- and 7-fold, respectively, depending on the grade of stainless steel. Longer cooking durations resulted in additional increases in metal leaching, where Ni concentrations increased 34-fold and Cr increased approximately 35-fold from sauces cooked without stainless steel. Cooking with new stainless steel resulted in the largest increases. Metal leaching decreases with sequential cooking cycles and stabilized after the sixth cooking cycle, although significant metal contributions to foods were still observed. The tenth cooking cycle resulted in an average of 88 ?g of Ni and 86 ?g of Cr leached per 126 g serving of tomato sauce. Stainless steel cookware can be an overlooked source of nickel and chromium, where the contribution is dependent on stainless steel grade, cooking time, and cookware usage. PMID:23984718

  15. 76 FR 43981 - Circular Welded Austenitic Stainless Pressure Pipe From the People's Republic of China: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ...Outokumpu Stainless Products...Austenitic Stainless Pressure Pipe from the People's...austenitic stainless pressure pipe not greater than...specifications. ASTM A-358 products are only included when...administrative review. Separate Rates In proceedings...

  16. 76 FR 31585 - Forged Stainless Steel Flanges From India: Notice of Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ...Administration [A-533-809] Forged Stainless Steel Flanges From India: Notice of...the antidumping duty order on forged stainless steel flanges from India. The period...the antidumping duty order on forged stainless steel flanges from India. See...

  17. 75 FR 62624 - WTO Dispute Settlement Proceeding Regarding United States-Final Antidumping Measures on Stainless...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ...States--Final Antidumping Measures on Stainless Steel from Mexico AGENCY: Office of...States--Final Antidumping Measures on Stainless Steel from Mexico to a panel. The request...States--Final Antidumping Measures on Stainless Steel from Mexico. The...

  18. 78 FR 7395 - Stainless Steel Bar From India: Preliminary Results of Antidumping Duty Administrative Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ...Trade Administration [A-533-810] Stainless Steel Bar From India: Preliminary Results...review of the antidumping duty order on stainless steel bar (SSB) from India. The period...Antidumping Duty Administrative Review: Stainless Steel Bar from India'' dated...

  19. 76 FR 28809 - Stainless Steel Plate From Belgium; Termination of Five-Year Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ...701-TA-376 (Second Review)] Stainless Steel Plate From Belgium; Termination...concerning the countervailing duty order on stainless steel plate from Belgium (75 FR 30777...countervailing duty order concerning stainless steel plate from Belgium, finding...

  20. 75 FR 81308 - Stainless Steel Sheet And Strip From Germany, Italy, Japan, Korea, Mexico, And Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ...Stainless Steel Sheet And Strip From Germany, Italy, Japan, Korea, Mexico, And...on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and...on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico,...

  1. 75 FR 59744 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ...Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and...on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and...on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico,...

  2. 75 FR 67110 - Forged Stainless Steel Flanges From India and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-01

    ...Forged Stainless Steel Flanges From India and Taiwan AGENCY: United States International...on forged stainless steel flanges from India and Taiwan...on forged stainless steel flanges from India and Taiwan would be likely to lead to...

  3. 78 FR 45271 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ...Preliminary)] Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam...and Vietnam of welded stainless steel pressure pipe, provided for in subheading 7306...LTFV imports of welded stainless steel pressure pipe from Malaysia, Thailand, and...

  4. 78 FR 62583 - Welded Stainless Pressure Pipe From Malaysia, Thailand, and the Socialist Republic of Vietnam...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ...A-549-830, A-552-816] Welded Stainless Pressure Pipe From Malaysia, Thailand, and the...duty investigations of welded stainless pressure pipe from Malaysia, Thailand, and the...1\\ See Welded Stainless Pressure Pipe From Malaysia, Thailand, and...

  5. pH optrode

    DOEpatents

    Northrup, M. Allen (Berkeley, CA); Langry, Kevin C. (Tracy, CA)

    1993-01-01

    A process is provided for forming a long-lasting, stable, pH-sensitive dye-acrylamide copolymer useful as a pH-sensitive material for use in an optrode or other device sensitive to pH. An optrode may be made by mechanically attaching the copolymer to a sensing device such as an optical fiber.

  6. pH Basics

    ERIC Educational Resources Information Center

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just

  7. Surface-protein interactions on different stainless steel grades: effects of protein adsorption, surface changes and metal release.

    PubMed

    Hedberg, Y; Wang, X; Hedberg, J; Lundin, M; Blomberg, E; Wallinder, I Odnevall

    2013-04-01

    Implantation using stainless steels (SS) is an example where an understanding of protein-induced metal release from SS is important when assessing potential toxicological risks. Here, the protein-induced metal release was investigated for austenitic (AISI 304, 310, and 316L), ferritic (AISI 430), and duplex (AISI 2205) grades in a phosphate buffered saline (PBS, pH 7.4) solution containing either bovine serum albumin (BSA) or lysozyme (LSZ). The results show that both BSA and LSZ induce a significant enrichment of chromium in the surface oxide of all stainless steel grades. Both proteins induced an enhanced extent of released iron, chromium, nickel and manganese, very significant in the case of BSA (up to 40-fold increase), whereas both proteins reduced the corrosion resistance of SS, with the reverse situation for iron metal (reduced corrosion rates and reduced metal release in the presence of proteins). A full monolayer coverage is necessary to induce the effects observed. PMID:23378148

  8. Cutting tool reliability analysis for variable feed milling of 17-4PH stainless steel

    Microsoft Academic Search

    Zdzislaw Klim; Elmekki Ennajimi; Marek Balazinski; Clment Fortin

    1996-01-01

    Variable feed machining has recently been proposed as a significant method to improve cutting tool life particularly for hard and diffucult to machine materials. This method, which is easy to apply in industry, has been shown to improve tool life in the order of 40% in certain cases. This paper presents a reliability model for the quantitative study of the

  9. Surface modification of superaustenitic and maraging stainless steels by low-temperature gas-phase carburization

    NASA Astrophysics Data System (ADS)

    Gentil, Johannes

    Low-temperature gas-phase carburization of 316L austenitic stainless steel was developed in recent years by the Swagelok company. This process generates great mechanical and electrochemical surface properties. Hardness, wear resistance, fatigue behavior, and corrosion resistance are dramatically improved, while the formation of carbides is effectively suppressed. This new technique is of technical, economical, but especially of scientific interest because the surface properties of common stainless steel can be enhanced to a level of more sophisticated and more expensive superalloys. The consequential continuation of previous research is the application of the carburization process to other steel grades. Differences in chemical composition, microstructure, and passivity between the various alloys may cause technical problems and it is expected that the initial process needs to be optimized for every specific material. This study presents results of low-temperature carburization of AL-6XN (superaustenitic stainless steel) and PH13-8Mo (precipitation-hardened martensitic stainless steel). Both alloys have been treated successfully in terms of creating a hardened surface by introducing high amounts of interstitially dissolved carbon. The surface hardness of AL-6XN was increased to 12GPa and is correlated with a colossal carbon supersaturation at the surface of up to 20 at.%. The hardened case develops a carburization time-dependent thickness between 10mum after one carburization cycle and up to 35mum after four treatments and remains highly ductile. Substantial broadening of X-ray diffraction peaks in low-temperature carburized superaustenitic stainless steels are attributed to the generation of very large compressive biaxial residual stresses. Those large stresses presumably cause relaxations of the surface, so-called undulations. Heavily expanded regions of carburized AL-6XN turn ferromagnetic. Non-carburized AL-6XN is known for its outstanding corrosion resistance, which is not impaired upon carburization. The passive film as analyzed by XPS is fully intact. Carbon concentration levels in PH13-8Mo reach 10 at.% and correlate with a surface hardness of up to 14GPa. Indication for the transformation from martensite to austenite during the process are observed. In this context, the shape of the carbon concentration-depth profile can be explained. Also the absence of carbides, as analyzed by TEM, can be rationalized. Upon cooling to room temperature, most of the austenite backtransforms into martensite and the surface regains its ferromagnetic properties. Compressive biaxial residual stresses in carburized PH13-8Mo are measured around (2--2.5)GPa. The applied low-temperature carburization process gives rise to a substantial loss in corrosion resistance of PH13-8Mo. Possible reasons including the observed formation of internal and external oxides as well as the change in alloy composition are discussed. Due to the penetration depth of X-rays into the probed specimen surface, a carbon concentration gradient may cause detectable asymmetry of diffraction peaks for certain alloys and under certain conditions. For the first time, this effect is rationalized, explained, and demonstrated on the basis of measured data.

  10. Aging degradation of cast stainless steel

    SciTech Connect

    Chopra, O.K.; Chung, H.M.

    1986-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich ..cap alpha..' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by ..cap alpha..' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450/sup 0/C. Data from Charpy-impact, tensile, and J-R curve 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 correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed.

  11. Stabilization and sensitization of stainless steels

    SciTech Connect

    Grubb, J.F.; Fritz, J.D. [Allegheny Ludlum Corp., Brackenridge, PA (United States)

    1997-12-01

    This investigation examines the intergranular corrosion resistance of both welded and unwelded type 304, 304L, 321, 321L, and 347 alloys after various sensitizing and or stabilizing heat treatments. The intergranular corrosion resistance was characterized using ASTM A262 test methods and the double loop electrochemical potentiodynamic reactivation testing (EPR). The results show that stabilization by itself is not sufficient to render austenitic stainless steel immune to sensitization. The EPR testing demonstrates that the double loop parameters for all alloys correlate well with corrosion rates measured with the ASTM A262 Practice B test.

  12. Helium damage in austenitic stainless steels

    SciTech Connect

    Caskey, G.R. Jr.; Mezzanotte, D.A. Jr.; Rawl, D.E. Jr.

    1983-01-01

    Helium produced by tritium decay was first shown to embrittle austenitic stainless steel at ambient temperature in tensile specimens of Nitronic-40 steel (Armco, Inc.). A long-term study was initiated to study this form of helium damage in five austenitic alloys. Results from this study have been analyzed by the J-integral technique and show a decrease in ductile fracture toughness with increasing He-3 concentration. Sustained-load cracking tests indicate that the stress intensity required to initiate and propagate a crack also decreases with increasing He-3 concentration. 9 figures, 3 tables.

  13. Superplastic deformation in two microduplex stainless steels

    SciTech Connect

    Lesuer, D.R.; Nieh, T.G.; Syn, C.K. [Lawrence Livermore National Lab., CA (United States); Taleff, E.M. [Texas Univ., Austin, TX (United States)

    1996-09-01

    The deformation behavior and mechanisms of superplastic flow in two microduplex stainless steels (SuperDux64 and Nitronic 19D) were studied at {similar_to}0.7T{sub m}. The two steels differed in initial grain size by a factor of 3. Both steels exhibited solute-drag-controlled grain boundary sliding in a high temperature {gamma}+{delta} phase field. In a lower temperature {gamma}+{sigma} phase field, the fine-grained steel ({bar L}=5{mu}m) exhibited climb-controlled grain boundary sliding and the coarser- grained steel ({bar L}=15{mu}m) exhibited solute-drag-controlled slip creep.

  14. A chromosome study among stainless steel welders

    SciTech Connect

    Husgafvel-Pursiainen, K.; Kalliomaeki, P.L.; Sorsa, M.

    1982-10-01

    The mutagenicity of welding fumes generated by manual metal arc (MMA) welding of stainless steel (SS) has been shown in several experimental in vitro systems. No data are available on possible chromosome damage among MMA/SS welders. In the present study, structural chromosome aberrations and sister chromatid exchanges (SCEs) were studied in peripheral blood lymphocytes of 23 welders and 22 control subjects. No significant differences in the frequency of chromosome aberrations or SCEs were detected between the two groups. Smokers, both welders and controls, showed a significantly higher SCE rate than non-smokers.

  15. Durable icephobic coating for stainless steel.

    PubMed

    Boinovich, Ludmila B; Emelyanenko, Alexandre M; Ivanov, Vladimir K; Pashinin, Andrei S

    2013-04-10

    In this work, we present a modification of a stainless steel surface to impart superhydrophobic properties to it that are robust with respect to mechanical stresses associated with cyclic icing/deicing treatment, as well as to long-term contact with aqueous media and high humidity. The durability of the superhydrophobic state is ensured by the texture with multimodal roughness stable against mechanical stresses and a 2D polymer network of fluorooxysilane chemically bound to the texture elements. The designed superhydrophobic coating is characterized by contact angles exceeding 155 and a maximum rolling angle of 42 after 100 icing/deicing cycles. PMID:23470194

  16. Acoustic emission from hydrogen saturated Type 304L stainless steel

    Microsoft Academic Search

    Caskey; G. R. Jr

    1979-01-01

    Effects of hydrogen on tensile deformation and fracture of austenitic stainless steels vary widely, depending upon the steel composition and treatment, hydrogen exposure, and loading conditions. In alloys such as Type 310 and Type 316 stainless steel, the ductility loss is small; and the fracture mode is unchanged. In contrast, Type 304L, 21-6-9, and Tenelon display large ductility losses with

  17. VIEW OF PRECISION EQUIPMENT USED IN STAINLESS COMPONENT MANUFACTURING. THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF PRECISION EQUIPMENT USED IN STAINLESS COMPONENT MANUFACTURING. THE FACILITY WAS DESCRIBED AS THE MOST MODERN NON-NUCLEAR MANUFACTURING BUILDING IN THE U.S. DEPARTMENT OF ENERGY COMPLEX, WITH MANY PRECISION INSTRUMENTS. (9/21/83) - Rocky Flats Plant, Stainless Steel & Non-Nuclear Components Manufacturing, Southeast corner of intersection of Cottonwood & Third Avenues, Golden, Jefferson County, CO

  18. Nanostructured nickel-free austenitic stainless steel/hydroxyapatite composites.

    PubMed

    Tulinski, Maciej; Jurczyk, Mieczyslaw

    2012-11-01

    In this work Ni-free austenitic stainless steels with nanostructure and their nanocomposites with hydroxyapatite are presented and characterized by means of X-ray diffraction and optical profiling. The samples were synthesized by mechanical alloying, heat treatment and nitriding of elemental microcrystalline powders with addition of hydroxyapatite (HA). In our work we wanted to introduce into stainless steel hydroxyapatite ceramics that have been intensively studied for bone repair and replacement applications. Such applications were chosen because of their high biocompatibility and ability to bond to bone. Since nickel-free austenitic stainless steels seem to have better mechanical properties, corrosion resistance and biocompatibility compared to 316L stainless steels, it is possible that composite made of this steel and HA could improve properties, as well. Mechanical alloying and nitriding are very effective technologies to improve the corrosion resistance of stainless steel. Similar process in case of nanocomposites of stainless steel with hydroxyapatite helps achieve even better mechanical properties and corrosion resistance. Hence nanocrystalline nickel-free stainless steels and nickel-free stainless steel/hydroxyapatite nanocomposites could be promising bionanomaterials for use as a hard tissue replacement implants, e.g., orthopedic implants. In such application, the surface roughness and more specifically the surface topography influences the proliferation of cells (e.g., osteoblasts). PMID:23421285

  19. Electrochemical noise from oxygen reduction on stainless steel surfaces

    Microsoft Academic Search

    Helmuth Sarmiento Klapper; Joachim Goellner

    2009-01-01

    Oxygen reduction occurring at the passive layer is probably the most important cathodic reaction involved in corrosion processes on stainless steel. Furthermore, the influence of the surface state on the oxygen reduction reaction is a key point for the understanding of the mechanism of localized corrosion on stainless steel. In this study, electrochemical noise measurements under cathodic polarization were carried

  20. Duplex Stainless Steel Welds and their Susceptibility to Intergranular Corrosion

    Microsoft Academic Search

    B. Gideon; L. Ward; G. Biddle

    Duplex stainless steels (DSS) as alternatives to conventional austenitic stainless steels for the construction of pipelines is becoming more wide-spread, particularly for sour service applications where corrosion resistance \\/ stress corrosion cracking resistance is required in aggressive chloride \\/ sulphide environments. While these steels show many superior characteristics, limitations are associated with the welding of these steels, particularly controlling the

  1. 6. DETAIL VIEW OF SPIN FORM FURNACE FOR STAINLESS STEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. DETAIL VIEW OF SPIN FORM FURNACE FOR STAINLESS STEEL FABRICATION. STAINLESS STEEL WAS MACHINED IN SIDE A OF THE BUILDING, BEGINNING IN 1957. (4/24/78) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  2. Mechanism of Dissimilar Metal Crevice Corrosion of Superferritic Stainless Steels

    Microsoft Academic Search

    G. Salamat; G. A. Juhl; R. G. Kelly

    1995-01-01

    Superferritic stainless steels (SS) can suffer from dissimilar metal crevice (DMC) corrosion when part of a crevice with certain other stainless alloys. For example, UNS S44735 is attacked when part of a crevice with type 316 SS (UNS S30400). To understand this phenomenon better, solutions which form inside such crevices were collected and analyzed with ion chromatography and capillary electrophoresis

  3. Metastable pitting in 25 Cr duplex stainless steel

    Microsoft Academic Search

    L. F Garfias-Mesias; J. M Sykes

    1999-01-01

    Evidence of metastable pitting in conventional austenitic stainless steels at room temperature is now common. Because of the small currents associated with individual events, most studies have been carried out on micro electrodes (typically 50 mm diameter). Here in contrast, with high chromium duplex stainless steels (DSS), metastable pitting is clearly observed on larger electrodes in tests at elevated temperatures

  4. Toward Improved Ductility and Toughness of Soft Martensitic Stainless Steel

    Microsoft Academic Search

    Yoshitaka IWABUCHI

    This paper details the factors affecting mechanical properties of soft martensitic stainless steel castings that have lower carbon contents and increased nickel contents of up to 6% compared with normal martensitic stainless steel castings. The effect of alloying elements and impurities on the microstructural features and tempering characteristics was considered in detail, with special reference to reverted austenite and temper

  5. Magnetic properties of stainless steels at room and cryogenic temperatures

    Microsoft Academic Search

    Paul Oxley; Jennifer Goodell; Robert Molt

    2009-01-01

    The magnetic properties of ten types of ferritic and martensitic stainless steels have been measured at room temperature and at 77K. The steel samples studied were in the annealed state as received from the manufacturer. Our room temperature measurements indicate significantly harder magnetic properties than those quoted in the ASM International Handbook, which studied fully annealed stainless steel samples. Despite

  6. Properties of duplex stainless steels made by powder metallurgy

    Microsoft Academic Search

    L. A. Dobrzaski; Z. Brytan; M. Actis Grande; M. Rosso

    Purpose: of this paper was to examine the mechanical properties of duplex stainless steels. Design\\/methodology\\/approach: In presented study duplex stainless steels were obtained through powder metallurgy starting from austenitic, martensitic base powders by controlled addition of alloying elements, such as Cr, Ni, Mo and Cu. In the studies behind the preparation of mixes, Schaeffler's diagram was taken into consideration. Prepared

  7. Effects of N and Mo on the electrochemical behavior of laser-alloyed stainless steels in a 3.5 wt.% NaCl solution

    Microsoft Academic Search

    Chong-Cheng Huang; Wen-Ta Tsai; Ju-Tung Lee

    1995-01-01

    The electrochemical behavior of the laser-alloyed Fe-Cr-Ni-Si-N and Fe-Cr-Ni-Mo-Si-N stainless steels was studied in a 3.5 wt.% NaCl solution. Cyclic potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) measurements were performed to evaluate the corrosion resistance of the alloyed layers in deaerated 3.5 wt.% NaCl solution at pH 4. The surfaces of the samples after EIS measurements were characterized with

  8. Open circuit potentials of metallic chromium and austenitic 304 stainless steel in aqueous sulphuric acid solution and the influence of chloride ions on them

    Microsoft Academic Search

    Bore Jegdi?; Dragutin M. Drai?; Jovan P. Popi?

    2008-01-01

    Open circuit potential measurements and cyclic voltammetry of chromium and 304 stainless steel in deaerated aqueous H2SO4 solution of pH 1, without and containing NaCl in the concentration range 14 M revealed that chromium exhibits two stable open circuit potentials both having the character of a WagnerTraud corrosion potential. One, Ecorr.1, was established on the passive surface formed by previously

  9. The performance of duplex stainless steels in chemical environments

    SciTech Connect

    Francis, R. [Weir Materials Ltd., Manchester (United Kingdom). Park Works

    1994-12-31

    The process industries have used 300 series stainless steels for many years where the corrosion resistance of carbon steel is inadequate. Where stainless steels have proved inadequate there has been a tendency to utilize high nickel alloys, with a greatly increased cost. The present paper reviews the different grades of duplex stainless steel and shows how their superior corrosion and stress corrosion cracking resistance, plus their high strength, can be utilized to provide cost effective alternatives to the high nickel alloys. The use of alternative design codes to take advantages of the properties of duplex alloys is discussed. Data is presented to show the resistance of duplex stainless steels to a variety of chemical environments. The use of duplex stainless steels and the reason for their selection in a number of applications is reviewed.

  10. Corrosion pits in thin films of stainless steel

    SciTech Connect

    Ryan, M.P.; Isaacs, H.S. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science] [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Laycock, N.J. [Materials Performance Technologies, Lower Hutt (New Zealand)] [Materials Performance Technologies, Lower Hutt (New Zealand); Newman, R.C. [Univ. of Manchester (United Kingdom). Inst. of Science and Technology] [Univ. of Manchester (United Kingdom). Inst. of Science and Technology

    1999-01-01

    Thin stainless steel films were prepared by sputter deposition onto silicon substrates using a 304 stainless steel target. The film composition was essentially that of 304 stainless steel, but they had a body-centered cubic structure and were free of sulfide inclusions. Potentiodynamic polarization curves were obtained for thin films in various chloride-containing solutions and compared to results from conventional stainless steel samples. In addition, video images of two-dimensional pits in thin films were used to determine the anodic pit current density as functions of potential and chloride concentration. Thin stainless steel films were found to be significantly more resistant to pit initiation than their bulk counterparts, but pit propagation was possible at relatively low potentials. A diffusion-controlled growth regime was identified at high potentials, with a transition to mixed activation/ohmic control at lower potentials (just above that required for repassivation).

  11. Evaluation of the stress corrosion behavior of selected stainless steels

    SciTech Connect

    Dorning, R.E. II

    1983-11-05

    The objective of this investigation was to determine the stress corrosion behavior of selected stainless steels in several fluorinating environments. The possibility of stress corrosion cracking or pitting which could substantially reduce the serviceability of the stainless steels was the primary concern. Laboratory testing indicated that stress corrosion cracking or other forms of localized attack of the austenitic stainless steels tested (304, 304-L, 316, and 316-L) would not occur in the dry gas environments investigated. AISI 316 and 316-L stainless steels exhibited no significant corrosion in any of the test environments. Stressed 304 and 304-L stainless steels exhibited increased general corrosion and pitting when moisture was added to the fluorinating environment. 3 refs., 1 fig., 3 tabs.

  12. Tensile-property characterization of thermally aged cast stainless steels

    SciTech Connect

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  13. Exercise and Pulmonary Hypertension (PH)

    MedlinePLUS

    ... Young Adult Issues Dating and Relationships College and Scholarships Family Planning Considering Adoption with PH The Adoption ... Young Adult Issues Dating and Relationships College and Scholarships Family Planning Considering Adoption with PH The Adoption ...

  14. Cast alumina forming austenitic stainless steels

    DOEpatents

    Muralidharan, Govindarajan; Yamamoto, Yukinori; Brady, Michael P

    2013-04-30

    An austenitic stainless steel alloy consisting essentially of, in terms of weight percent ranges 0.15-0.5C; 8-37Ni; 10-25Cr; 2.5-5Al; greater than 0.6, up to 2.5 total of at least one element selected from the group consisting of Nb and Ta; up to 3Mo; up to 3Co; up to 1W; up to 3Cu; up to 15Mn; up to 2Si; up to 0.15B; up to 0.05P; up to 1 total of at least one element selected from the group consisting of Y, La, Ce, Hf, and Zr; <0.3Ti+V; <0.03N; and, balance Fe, where the weight percent Fe is greater than the weight percent Ni, and wherein the alloy forms an external continuous scale comprising alumina, and a stable essentially single phase FCC austenitic matrix microstructure, the austenitic matrix being essentially delta-ferrite free and essentially BCC-phase-free. A method of making austenitic stainless steel alloys is also disclosed.

  15. Embrittlement of austenitic stainless steel welds

    SciTech Connect

    David, S.A.; Vitek, J.M. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1997-12-31

    The microstructure of type-308 austenitic stainless steel weld metal containing {gamma} and {delta} and ferrite is shown. Typical composition of the weld metal is Cr-20.2, Ni-9.4, Mn-1.7, Si-0.5, C-0.05, N-0.06 and balance Fe (in wt %). Exposure of austenitic stainless steel welds to elevated temperatures can lead to extensive changes in the microstructural features of the weld metal. On exposure to elevated temperatures over a long period of time, a continuous network of M{sub 23}C{sub 6} carbide forms at the austenite/ferrite interface. Upon aging at temperatures between 550--850 C, ferrite in the weld has been found to be unstable and transforms to sigma phase. These changes have been found to influence mechanical behavior of the weld metal, in particular the creep-rupture properties. For aging temperatures below 550 C the ferrite decomposes spinodally into {alpha} and {alpha}{prime} phases. In addition, precipitation of G-phase occurs within the decomposed ferrite. These transformations at temperatures below 550 C lead to embrittlement of the weld metal as revealed by the Charpy impact properties.

  16. Weldment for austenitic stainless steel and method

    DOEpatents

    Bagnall, Christopher (Hempfield, PA); McBride, Marvin A. (Hempfield, PA)

    1985-01-01

    For making defect-free welds for joining two austenitic stainless steel mers, using gas tungsten-arc welding, a thin foil-like iron member is placed between the two steel members to be joined, prior to making the weld, with the foil-like iron member having a higher melting point than the stainless steel members. When the weld is formed, there results a weld nugget comprising melted and then solidified portions of the joined members with small portions of the foil-like iron member projecting into the solidified weld nugget. The portions of the weld nugget proximate the small portions of the foil-like iron member which project into the weld nugget are relatively rich in iron. This causes these iron-rich nugget portions to display substantial delta ferrite during solidification of the weld nugget which eliminates weld defects which could otherwise occur. This is especially useful for joining austenitic steel members which, when just below the solidus temperature, include at most only a very minor proportion of delta ferrite.

  17. Citric Acid Passivation of Stainless Steel

    NASA Technical Reports Server (NTRS)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  18. The pH scale

    NSDL National Science Digital Library

    Olivia Worland (Purdue University; Biological Sciences)

    2008-05-26

    Some animals tolerate broad changes in pH well while others do not. Human activities can create acid rain. Acid rain can change the pH of the environment and destroy entire ecosystems and habitats. For an ecosystem to function properly, its pH must be able to accommodate all of the organisms living in it.

  19. Urine pH test

    MedlinePLUS

    A urine pH test measures the level of acid in urine. ... pH - urine ... meat products or cranberries can decrease your urine pH. ... to check for changes in your body's acid levels.It may be done to ... more effective when urine is acidic or non-acidic (alkaline).

  20. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Microsoft Academic Search

    Songqing Wen; Carl Lundin; Greg Batten

    2005-01-01

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison

  1. Hydrogen assisted stress-cracking behaviour of electron beam welded supermartensitic stainless steel weldments

    Microsoft Academic Search

    P. Bala Srinivasan; S. W. Sharkawy; W. Dietzel

    2004-01-01

    Supermartensitic stainless steel (SMSS) grades are gaining popularity as an alternate material to duplex and super duplex stainless steels for applications in oil and gas industries. The weldability of these steels, though reported to be better when compared to conventional martensitic stainless steels, so far has been addressed with duplex stainless steel electrodes\\/fillers. This work addresses the stress-cracking behaviour of

  2. Global stainless steel cycle exemplifies China's rise to metal dominance.

    PubMed

    Reck, Barbara K; Chambon, Marine; Hashimoto, Seiji; Graedel, T E

    2010-05-15

    The use of stainless steel, a metal employed in a wide range of technology applications, has been characterized for 51 countries and the world for the years 2000 and 2005. We find that the global stainless steel flow-into-use increased by more than 30% in that 5 year period, as did additions to in-use stocks. This growth was mainly driven by China, which accounted for almost half of the global growth in stainless steel crude production and which tripled its flow into use between 2000 and 2005. The global stainless steel-specific end-of-life recycling rate increased from 66% (2000) to 70% (2005); the landfilling rate was 22% for both years, and 9% (2000) to 12% (2005) was lost into recycled carbon and alloy steels. Within just 5 years, China passed such traditionally strong stainless steel producers and users as Japan, USA, Germany, and South Korea to become the dominant player of the stainless steel industry. However, China did not produce any significant stainless steel end-of-life flows in 2000 or 2005 because its products-in-use are still too new to require replacements. Major Chinese discard flows are expected to begin between 2015 and 2020. PMID:20426460

  3. High-strength stainless steels for corrosion mitigation in prestressed concrete: Development and evaluation

    NASA Astrophysics Data System (ADS)

    Moser, Robert D.

    Corrosion of prestressing reinforcement in concrete structures exposed to marine environments and/or deicing chemicals is a problem of critical concern. While many corrosion mitigation technologies are available for reinforced concrete (RC), those available for use in prestressed concrete (PSC) are limited and in many cases cannot provide the 100+ year service life needed in new construction, particularly when exposed to severe marine environments. The use of stainless steel alloys in RC structures has shown great success in mitigating corrosion in even the most severe of exposures. However, the use of high-strength stainless steels (HSSSs) for corrosion mitigation in PSC structures has received limited attention. To address these deficiencies in knowledge, an experimental study was conducted to investigate the feasibility of using HSSSs for corrosion mitigation in PSC. The study examined mechanical behavior, corrosion resistance, and techniques for the production of HSSS prestressing strands. Stainless steel grades 304, 316, 2101, 2205, 2304, and 17-7 were produced as cold drawn wires with diameters of approximately 4 mm (0.16 in). A 1080 prestressing steel was also included to serve as a control. Tensile strengths of 1250 to 1550 MPa (181 to 225 ksi) were achieved in the cold-drawn candidate HSSSs. Non-ductile failure modes with no post-yield strain hardening were observed in all candidate HSSSs. 1000 hr stress relaxation of all candidate HSSSs was predicted to be between 6 and 8 % based on the results of 200 hr tests conducted at 70 % of the ultimate tensile strength. Residual stresses due to the cold drawing had a significant influence on stress vs. strain behavior and stress relaxation. Electrochemical corrosion testing found that in solutions simulating alkaline concrete, all candidate HSSSs showed exceptional corrosion resistance at chloride (Cl-) concentrations from zero to 0.25 M. However, when exposed to solutions simulating carbonated concrete, corrosion resistance was reduced and the only candidate HSSSs with acceptable corrosion resistance were duplex grades 2205 and 2304, with 2205 being resistant to corrosion initiation at Cl- concentrations of up to 1.0 M (twice the Cl- concentration in seawater). A strong correlation between microstructural defects and corrosion damage was observed in the heavily cold-drawn HSSSs. Based on these results, duplex grades 2205 and 2304 were identified as optimal HSSSs and were included in additional studies which found that: (1) 2304 is susceptible to corrosion when tested in a stranded geometry, (2) 2205 and 2304 are not susceptible to stress corrosion cracking, and (3) 2205 and 2304 are susceptible to hydrogen embrittlement. Efforts focused on the production of 2205 and 2304 prestressing strands showed that they could be produced as strands using existing ASTM A416 prestressing strand production facilities. Due to the ferromagnetic properties of 2205 and 2304, a low-relaxation heat treatment to reduce stress relaxation and improve mechanical properties was also found to be feasible. The overall conclusion of the study was that HSSSs, especially duplex grades 2205 and 2304, show excellent promise to mitigate corrosion if utilized as prestressing reinforcement in PSC structures exposed to severe marine environments.

  4. Analysis of Stainless Steel Sandwich Panels with a Metal Foam Care for Lightweight Fan Blade Design

    NASA Technical Reports Server (NTRS)

    Min, James B.; Ghosn, Louis J.; Lerch, Bradley A.; Raj, Sai V.; Holland, Frederic A., Jr.; Hebsur, Mohan G.

    2004-01-01

    The quest for cheap, low density and high performance materials in the design of aircraft and rotorcraft engine fan and propeller blades poses immense challenges to the materials and structural design engineers. Traditionally, these components have been fabricated using expensive materials such as light weight titanium alloys, polymeric composite materials and carbon-carbon composites. The present study investigates the use of P sandwich foam fan blade made up of solid face sheets and a metal foam core. The face sheets and the metal foam core material were an aerospace grade precipitation hardened 17-4 PH stainless steel with high strength and high toughness. The stiffness of the sandwich structure is increased by separating the two face sheets by a foam core. The resulting structure possesses a high stiffness while being lighter than a similar solid construction. Since the face sheets carry the applied bending loads, the sandwich architecture is a viable engineering concept. The material properties of 17-4 PH metal foam are reviewed briefly to describe the characteristics of the sandwich structure for a fan blade application. A vibration analysis for natural frequencies and P detailed stress analysis on the 17-4 PH sandwich foam blade design for different combinations of skin thickness and core volume %re presented with a comparison to a solid titanium blade.

  5. Mitigating Localized Corrosion Using Thermally Sprayed Aluminum (TSA) Coatings on Welded 25% Cr Superduplex Stainless Steel

    NASA Astrophysics Data System (ADS)

    Paul, S.; Lu, Q.; Harvey, M. D. F.

    2015-02-01

    Thermally sprayed aluminum (TSA) coating has been increasingly used for the protection of carbon steel offshore structures, topside equipment, and flowlines/pipelines exposed to both marine atmospheres and seawater immersion conditions. In this paper, the effectiveness of TSA coatings in preventing localized corrosion, such as pitting and crevice corrosion of 25% Cr superduplex stainless steel (SDSS) in subsea applications, has been investigated. Welded 25% Cr SDSS (coated and uncoated) with and without defects, and surfaces coated with epoxy paint were also examined. Pitting and crevice corrosion tests, on welded 25% Cr SDSS specimens with and without TSA/epoxy coatings, were conducted in recirculated, aerated, and synthetic seawater at 90 C for 90 days. The tests were carried out at both the free corrosion potentials and an applied cathodic potential of -1100 mV saturated calomel electrode. The acidity (pH) of the test solution was monitored daily and adjusted to between pH 7.5 and 8.1, using dilute HCl solution or dilute NaOH, depending on the pH of the solution measured during the test. The test results demonstrated that TSA prevented pitting and crevice corrosion of 25% Cr SDSS in artificial seawater at 90 C, even when 10-mm-diameter coating defect exposing the underlying steel was present.

  6. Biotherapeutic formulation factors affecting metal leachables from stainless steel studied by design of experiments.

    PubMed

    Zhou, Shuxia; Evans, Brad; Schneich, Christian; Singh, Satish K

    2012-03-01

    Trace amounts of metals are inevitably present in biotherapeutic products. They can arise from various sources. The impact of common formulation factors such as protein concentration, antioxidant, metal chelator concentration and type, surfactant, pH, and contact time with stainless steel on metal leachables was investigated by a design of experiments approach. Three major metal leachables, iron, chromium, and nickel were monitored by inductively coupled plasma-mass spectrometry. It was observed that among all the tested factors, contact time, metal chelator concentration, and protein concentration were statistically significant factors with higher temperature resulting in higher levels of leached metals. Within a pH range of 5.5-6.5, solution pH played a minor role for chromium leaching at 25C. No statistically significant difference was observed due to type of chelator, presence of antioxidant, or surfactant. In order to optimize a biotherapeutic formulation to achieve a target drug product shelf life with acceptable quality, each formulation component must be evaluated for its impact. PMID:22246735

  7. Cryogenic coefficient of thermal expansion measurements of type 440 and 630 stainless steel

    NASA Astrophysics Data System (ADS)

    Cease, H.; Alvarez, M.; Flaugher, B.; Montes, J.

    2014-01-01

    The Dark Energy Camera is now installed on the Blanco 4m telescope at the Cerro Tololo Inter-American Observatory in Chile. The camera is cooled to 170K using a closed loop two-phase liquid nitrogen system. A submerged centrifugal pump is used to circulate the liquid from the base of the telescope to the camera in the prime focus cage. As part of the pump maintenance schedule, the rotor shaft bearings are periodically replaced. Common bearing and shaft materials are type 440 and 630 (17-4 PH) stainless steel. The coefficient of thermal expansion of the materials used is needed to predict the shaft and bearing housing dimensional changes at the 77K pump operating temperature. The thermal expansion from room temperature to 77K of type 440 and 630 stainless steel is presented . Measurements are performed using the ASTM E228 standard with a quartz push-rod dilatometer test stand. Aluminum 6061-T6 is used to calibrate the test stand.

  8. Effect of condenser design on stress corrosion cracking of stainless alloys in boiling chloride solutions

    SciTech Connect

    Chiang, Y.L.; Streicher, M.A. [Univ. of Delaware, Newark, DE (United States)

    1998-09-01

    The design of condensers used to reflux boiling chloride solutions for stress corrosion tests on stainless alloys was shown to have a significant effect on time to cracking. This effect resulted from the different steady-state concentrations of oxygen produced by various types of condensers. The condenser that provided the least amount of preheating before returning the condensate to the solution established the largest concentrations of air (oxygen) in the boiling solution and the shortest times to failure by stress corrosion cracking (SCC). This was demonstrated with magnesium chloride (MgCl{sub 2}) and sodium chloride (NaCl) solutions on type 304 stainless steel (UNS S30400), Carpenter 20 Cb-3 (UNS N08020), and Incoloy 825 (UNS N08825). In MgCl{sub 2}, the effect of oxygen on stress corrosion depended upon the concentration of the solution. The effect was maximum in the range from 24% to 32% and decreased or disappeared at higher concentrations depending upon the alloy. These findings can be used to assess previously published data, for the design of new experiments, and for the development of new evaluation tests. Using a solution of 26% NaCl with phosphoric acid (H{sub 3}PO{sub 4}) to reduce the pH to 1.0 provides a more realistic method for evaluating alloys for service on plants than testing in MgCl{sub 2} solutions.

  9. Kinetics of Pseudomonas aeruginosa adhesion to 304 and 316-L stainless steel: role of cell surface hydrophobicity.

    PubMed Central

    Vanhaecke, E; Remon, J P; Moors, M; Raes, F; De Rudder, D; Van Peteghem, A

    1990-01-01

    Fifteen different isolates of Pseudomonas aeruginosa were used to study the kinetics of adhesion to 304 and 316-L stainless steel. Stainless steel plates were incubated with approximately 1.5 X 10(7) CFU/ml in 0.01 M phosphate-buffered saline (pH 7.4). After the plates were rinsed with the buffer, the number of adhering bacteria was determined by a bioluminescence assay. Measurable adhesion, even to the electropolished surfaces, occurred within 30 s. Bacterial cell surface hydrophobicity, as determined by the bacterial adherence to hydrocarbons test and the contact angle measurement test, was the major parameter influencing the adhesion rate constant for the first 30 min of adhesion. A parabolic relationship between the CAM values and the logarithm of the adhesion rate constants (In k) was established. No correlation between either the salt aggregation or the improved salt aggregation values and the bacterial adhesion rate constants could be found. Since there was no significant correlation between the bacterial electrophoretic mobilities and the In k values, the bacterial cell surface charge seemed of minor importance in the process of adhesion of P. aeruginosa to 304 and 316-L stainless steel. PMID:2107796

  10. Materials compatibility of hydride storage materials with austenitic stainless steels

    SciTech Connect

    Clark, E.A.

    1992-09-21

    This task evaluated the materials compatibility of LaNi[sub 5-x]Al[sub x] (x= 0.3, 0.75) hydrides and palladium coated kieselguhr with austenitic stainless steel in hydrogen and tritium process environments. Based on observations of retired prototype hydride storage beds and materials exposure testing samples designed for this study, no materials compatibility problem was indicated. Scanning electron microscopy observations of features on stainless steel surfaces after exposure to hydrides are also commonly found on as-received materials before hydriding. These features are caused by either normal heat treating and acid cleaning of stainless steel or reflect the final machining operation.

  11. Materials compatibility of hydride storage materials with austenitic stainless steels

    SciTech Connect

    Clark, E.A.

    1992-09-21

    This task evaluated the materials compatibility of LaNi{sub 5-x}Al{sub x} (x= 0.3, 0.75) hydrides and palladium coated kieselguhr with austenitic stainless steel in hydrogen and tritium process environments. Based on observations of retired prototype hydride storage beds and materials exposure testing samples designed for this study, no materials compatibility problem was indicated. Scanning electron microscopy observations of features on stainless steel surfaces after exposure to hydrides are also commonly found on as-received materials before hydriding. These features are caused by either normal heat treating and acid cleaning of stainless steel or reflect the final machining operation.

  12. Stress-corrosion cracking of sensitized type 304 stainless steel in thiosulfate solutions

    NASA Astrophysics Data System (ADS)

    Newman, R. C.; Sieradzki, K.; Isaacs, H. S.

    1982-11-01

    The stress corrosion cracking of a sensitized Type 304 stainless steel has been studied at room temperature using controlled potentials and two concentrations of sodium thiosulfate. In both constant extension rate and constant load tests, the crack velocities attain extremely high values, up to 8 ?m s-1. Scratching electrode experiments conducted at various pH values on simulated grain boundary material show that both the crack initiation frequency and crack velocity are closely related to the repassivation rate of the grain boundary material as expected on a dissolution-controlled mechanism; however, the maximum crack velocity at any potential is consistently about two orders of magnitude higher than that predicted from the electrochemical data. Frequent grain boundary separation ahead of the crack tip is thought to occur, but retarded repassivation of the grain boundary material is a necessary feature of the cracking. Effects of strain-generated martensite are discussed.

  13. Nanotextured stainless steel for improved corrosion resistance and biological response in coronary stenting

    NASA Astrophysics Data System (ADS)

    Mohan, Chandini C.; Prabhath, Anupama; Cherian, Aleena Mary; Vadukumpully, Sajini; Nair, Shantikumar V.; Chennazhi, Krishnaprasad; Menon, Deepthy

    2014-12-01

    Nanosurface engineering of metallic substrates for improved cellular response is a persistent theme in biomaterials research. The need to improve the long term prognosis of commercially available stents has led us to adopt a `polymer-free' approach which is cost effective and industrially scalable. In this study, 316L stainless steel substrates were surface modified by hydrothermal treatment in alkaline pH, with and without the addition of a chromium precursor, to generate a well adherent uniform nanotopography. The modified surfaces showed improved hemocompatibility and augmented endothelialization, while hindering the proliferation of smooth muscle cells. Moreover, they also exhibited superior material properties like corrosion resistance, surface integrity and reduced metal ion leaching. The combination of improved corrosion resistance and selective vascular cell viability provided by nanomodification can be successfully utilized to offer a cell-friendly solution to the inherent limitations pertinent to bare metallic stents.

  14. Corrosivity of paper mill effluent and corrosion performance of stainless steel.

    PubMed

    Ram, Chhotu; Sharma, Chhaya; Singh, A K

    2015-03-01

    Present study relates to the corrosivity of paper mill effluent and corrosion performance of stainless steel (SS) as a construction material for the effluent treatment plant (ETP). Accordingly, immersion test and electrochemical polarization tests were performed on SS 304?L, 316?L and duplex 2205 in paper mill effluent and synthetic effluent. This paper presents electrochemical polarization measurements, performed for the first time to the best of the authors' information, to see the influence of chlorophenols on the corrosivity of effluents. The corrosivity of the effluent was observed to increase with the decrease in pH and increase in Cl(-) content while the addition of [Formula: see text] tends to inhibit corrosion. Mill effluent was found to be more corrosive as compared to synthetic effluent and has been attributed to the presence of various chlorophenols. Corrosion performance of SS was observed to govern by the presence of Cr, Mo and N contents. PMID:25188842

  15. Radiation resistant austenitic stainless steel alloys

    DOEpatents

    Maziasz, Philip J. (Oak Ridge, TN); Braski, David N. (Oak Ridge, TN); Rowcliffe, Arthur F. (Oak Ridge, TN)

    1989-01-01

    An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01% to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties.

  16. Radiation resistant austenitic stainless steel alloys

    DOEpatents

    Maziasz, P.J.; Braski, D.N.; Rowcliffe, A.F.

    1987-02-11

    An austenitic stainless steel alloy, with improved resistance to radiation-induced swelling and helium embrittlement, and improved resistance to thermal creep at high temperatures, consisting essentially of, by weight percent: from 16 to 18% nickel; from 13 to 17% chromium; from 2 to 3% molybdenum; from 1.5 to 2.5% manganese; from 0.01 to 0.5% silicon; from 0.2 to 0.4% titanium; from 0.1 to 0.2% niobium; from 0.1 to 0.6% vanadium; from 0.06 to 0.12% carbon; from 0.01 to 0.03% nitrogen; from 0.03 to 0.08% phosphorus; from 0.005 to 0.01% boron; and the balance iron, and wherein the alloy may be thermomechanically treated to enhance physical and mechanical properties. 4 figs.

  17. 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.

  18. 50 CFR 17.7 - Raptor exemption.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...live migratory bird of the Order Falconiformes or the Order Strigiformes, other than a bald eagle (Haliaeetus leucocephalus ) or a golden eagle (Aquila chrysaetos )] legally held in captivity or in a controlled environment on...

  19. 50 CFR 17.7 - Raptor exemption.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...live migratory bird of the Order Falconiformes or the Order Strigiformes, other than a bald eagle (Haliaeetus leucocephalus ) or a golden eagle (Aquila chrysaetos )] legally held in captivity or in a controlled environment on...

  20. 50 CFR 17.7 - Raptor exemption.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...live migratory bird of the Order Falconiformes or the Order Strigiformes, other than a bald eagle (Haliaeetus leucocephalus ) or a golden eagle (Aquila chrysaetos )] legally held in captivity or in a controlled environment on...

  1. 50 CFR 17.7 - Raptor exemption.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...live migratory bird of the Order Falconiformes or the Order Strigiformes, other than a bald eagle (Haliaeetus leucocephalus ) or a golden eagle (Aquila chrysaetos )] legally held in captivity or in a controlled environment on...

  2. 50 CFR 17.7 - Raptor exemption.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...live migratory bird of the Order Falconiformes or the Order Strigiformes, other than a bald eagle (Haliaeetus leucocephalus ) or a golden eagle (Aquila chrysaetos )] legally held in captivity or in a controlled environment on...

  3. Stainless steel anodes for alkaline water electrolysis and methods of making

    DOEpatents

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  4. The partitioning of alloying elements in vacuum arc remelted, Pd-modified PH 13-8 Mo alloys

    Microsoft Academic Search

    M. J. Cieslak; J. A. Vandenavyle; M. J. Carr; C. R. Hills; R. E. Semarge

    1988-01-01

    The partitioning of alloying elements in as-solidified PH 13-8 Mo stainless steel containing up to 1.02 wt pct Pd has been\\u000a investigated. The as-solidified structure is composed of two major phases, martensite and ferrite. Electron probe microanalysis\\u000a reveals that Mo, Cr, and Al partition to the ferrite phase while Fe, Ni, Mn, and Pd partition to the martensite (prior austenite)

  5. The partitioning of alloying elements in vacuum arc remelted, Pd-modified PH 13-8 Mo alloys

    Microsoft Academic Search

    M. J. Cieslak; J. A. Vandenavyle; M. J. Carr; C. R. Hills; R. E. Semarge

    1988-01-01

    The partitioning of alloying elements in as-solidified PH 13-8 Mo stainless steel containing up to 1.02 wt pct Pd has been investigated. The as-solidified structure is composed of two major phases, martensite and ferrite. Electron probe microanalysis reveals that Mo, Cr, and Al partition to the ferrite phase while Fe, Ni, Mn, and Pd partition to the martensite (prior austenite)

  6. Eddy sensors for small diameter stainless steel tubes.

    SciTech Connect

    Skinner, Jack L.; Morales, Alfredo Martin; Grant, J. Brian; Korellis, Henry James; LaFord, Marianne Elizabeth; Van Blarigan, Benjamin; Andersen, Lisa E.

    2011-08-01

    The goal of this project was to develop non-destructive, minimally disruptive eddy sensors to inspect small diameter stainless steel metal tubes. Modifications to Sandia's Emphasis/EIGER code allowed for the modeling of eddy current bobbin sensors near or around 1/8-inch outer diameter stainless steel tubing. Modeling results indicated that an eddy sensor based on a single axial coil could effectively detect changes in the inner diameter of a stainless steel tubing. Based on the modeling results, sensor coils capable of detecting small changes in the inner diameter of a stainless steel tube were designed, built and tested. The observed sensor response agreed with the results of the modeling and with eddy sensor theory. A separate limited distribution SAND report is being issued demonstrating the application of this sensor.

  7. Stainless-steel elbows formed by spin forging

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Large seamless austenitic stainless steel elbows are fabricated by spin forging /rotary shear forming/. A specially designed spin forging tool for mounting on a hydrospin machine has been built for this purpose.

  8. Stainless Steel in Waste Packages for TSPA-SR

    SciTech Connect

    C.D. Leigh

    2000-06-12

    The objective of the calculation is to determine how commercial spent nuclear fuel (CSNF) stainless-steel clad assemblies are distributed over the CSNF waste packages (WPs) in the Yucca Mountain repository. The calculation defines the number of CSNF WPs that will contain stainless-steel clad assemblies, and the stainless steel content, on average, in those WPs for the Total System Performance Assessment in Support of Site Recommendation (TSPA-SR). Cladding models for TSPA-SR for stainless-steel clad assemblies differ from the models used for zirconium-clad assemblies. The information derived in this calculation helps to determine how the-cladding models are applied to WPs in TSPA-SR. The calculation addresses the WP configurations for CSNF defined in an interoffice correspondence from E.P. Stroupe to D.R. Wilkins (Stroupe 2000) and shown in Table 1.

  9. Surface modified stainless steels for PEM fuel cell bipolar plates

    DOEpatents

    Brady, Michael P [Oak Ridge, TN; Wang, Heli [Littleton, CO; Turner, John A [Littleton, CO

    2007-07-24

    A nitridation treated stainless steel article (such as a bipolar plate for a proton exchange membrane fuel cell) having lower interfacial contact electrical resistance and better corrosion resistance than an untreated stainless steel article is disclosed. The treated stainless steel article has a surface layer including nitrogen-modified chromium-base oxide and precipitates of chromium nitride formed during nitridation wherein oxygen is present in the surface layer at a greater concentration than nitrogen. The surface layer may further include precipitates of titanium nitride and/or aluminum oxide. The surface layer in the treated article is chemically heterogeneous surface rather than a uniform or semi-uniform surface layer exclusively rich in chromium, titanium or aluminum. The precipitates of titanium nitride and/or aluminum oxide are formed by the nitriding treatment wherein titanium and/or aluminum in the stainless steel are segregated to the surface layer in forms that exhibit a low contact resistance and good corrosion resistance.

  10. Fatigue behavior of welded austenitic stainless steel in different environments

    NASA Astrophysics Data System (ADS)

    Yawas, D. S.; Aku, S. Y.; Aluko, S. O.

    The fatigue behavior of welded austenitic stainless steel in 0.5 M hydrochloric acid and wet steam corrosive media has been investigated. The immersion time in the corrosive media was 30 days to simulate the effect on stainless steel structures/equipment in offshore and food processing applications and thereafter annealing heat treatment was carried out on the samples. The findings from the fatigue tests show that seawater specimens have a lower fatigue stress of 0.5 10-5 N/mm2 for the heat treated sample and 0.1 10-5 N/mm2 for the unheat-treated sample compared to the corresponding hydrochloric acid and steam samples. The post-welding heat treatment was found to increase the mechanical properties of the austenitic stainless steel especially tensile strength but it reduces the transformation and thermal stresses of the samples. These findings were further corroborated by the microstructural examination of the stainless steel specimen.

  11. Stress corrosion cracking evaluation of precipitation-hardening stainless steel

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.; Nelson, E. E.

    1970-01-01

    Accelerated test program results show which precipitation hardening stainless steels are resistant to stress corrosion cracking. In certain cases stress corrosion susceptibility was found to be associated with the process procedure.

  12. The effects of alpha particle irradiation on stainless steel

    E-print Network

    Shipp, John Douglas

    1999-01-01

    A Monte Carlo code was developed to calculate the alpha particle emission rate from WGPu. It yielded information pertaining to the alpha particle source strength at the WGPU and stainless steel interface as well as the damage production and He...

  13. Ultrasonics permits brazing complex stainless steel assembly without flux

    NASA Technical Reports Server (NTRS)

    Baker, W. H.

    1967-01-01

    Ultrasonic vibration of an assembly of stainless steel instrumentation tubes ensures brazing without flux. Vibration with an ultrasonic transducer permits the brazing material to flow down each tube in contact with a seal plug installed in a pressure vessel wall.

  14. Electrochemical corrosion behavior of a novel antibacterial stainless steel

    Microsoft Academic Search

    Yongqian Liu; Jibiao Li; Emeka E. Oguzie; Ying Li; Demin Chen; Ke Yang; Fuhui Wang

    2009-01-01

    A novel antibacterial stainless steel (ASS) with martenstic microstructure has been recently developed, by controlled copper ion implantation, as a new functional material having broad-spectrum antibacterial properties. The electrochemical corrosion behavior of the ASS in 0.05mol\\/L NaCl was assessed using linear polarization and electrochemical impedance spectroscopy (EIS) and compared with that of a conventional stainless steel (SS) without copper ion

  15. Erosioncorrosion of stainless steels, titanium, tantalum and zirconium

    Microsoft Academic Search

    Mara-Dolores Bermdez; Francisco J. Carrin; Gins Martnez-Nicols; Rosa Lpez

    2005-01-01

    The observation of in-plant failures of AISI 304L stainless steel and Ta2.5W alloy, promoted the investigation of the erosioncorrosion behaviour of stainless steels AISI 304L and 316L and highly corrosion resistant reactive or refractory metals such as Ti, Ta and Zr.Erosioncorrosion tests were carried out by immersing the materials in an aqueous solution containing 10wt% HCl in the presence of

  16. Characterization of borided AISI 316L stainless steel implant

    Microsoft Academic Search

    I. zbek; B. A. Konduk; C. Bindal; A. H. Ucisik

    2002-01-01

    The present study reports on characterization of borided AISI 316L stainless steel implant. Boronizing heat treatment was performed on a cylindrical bar of AISI 316L austenitic surgical stainless steel with a diameter of 2mm and a length of 10mm using slurry salt bath consisting of borax, boric acid and ferro-silicon. The susbstrate AISI 316L was essentially containing 0.022wt% C, 0.79wt%

  17. Marine Atmospheric SCC of Unsensitized Stainless Steel Rock Climbing Protection

    Microsoft Academic Search

    A. Sjong; L. Eiselstein

    2008-01-01

    A failure investigation into the root cause of fixed austenitic stainless steel climbing anchor hardware in tropical marine\\u000a climates has been presented. The incident 316L climbing anchor was fixed in a seaside limestone cliff in southern Thailand\\u000a and underwent transgranular chloride stress corrosion cracking (TGSCC) after 10 years of service. Since stainless steel does\\u000a not normally undergo stress corrosion cracking

  18. Nickel in food: the role of stainless-steel utensils.

    PubMed

    Brun, R

    1979-01-01

    Nickel may be found in prepared foods (tinned foods) at markedly higher concentrations than the safe threshold laid down for hypersensitive patients. Some foodstuffs cooked in stainless-steel utensils attack the metal and thus contain much more nickel than when enamel or aluminum saucepans are used. Among the natural organic acids which may be responsible for dissolving stainless-steel, oxalic acid is the most active at equivalent concentrations. PMID:421457

  19. Micro Machine Parts Fabricated from Aqueous Based Stainless Steel Slurry

    Microsoft Academic Search

    Mohamed Imbaby; Isaac Chang; Kyle Jiang

    \\u000a A fabrication process of stainless steel micro components from metallic powder is reported. The process consists of two stages.\\u000a In the first stage, high quality SU-8 master moulds and their negative replicas from soft moulds are produced using photolithography\\u000a and soft moulding techniques respectively. The second stage includes preparation of stainless steel slurry, filling the soft\\u000a mould, obtaining the green

  20. Application of Cost-Effective Stainless Steel for Automotive Components

    Microsoft Academic Search

    K. Hariharan; G. Balachandran; M. Sathya Prasad

    2009-01-01

    High-strength nickel free austenitic stainless steel material as a light-weight substitute for commercial automotive deep drawn steel has been studied with an automotive bumper as an example. The stainless steel gave a weight saving as high as 50% at the same cost that of deep drawn steels. The study examines the techno-economic merits of value engineering automotive material. The bumper

  1. Properties of a new family of stainless steels without nickel

    Microsoft Academic Search

    J. Lefevre; R. Tricot; A. Gueussier; R. Castro

    1974-01-01

    Many applications in which stainless steels are employed call for good corrosion resistance and, at the same time, for good\\u000a weldability. The new family of stainless steels which we propose to describe is related by its structure to the steels of\\u000a the ferritic group and by its properties,i.e., the ductility of its welds and its corrosion resistance, to the steels

  2. Hydrogen transport and hydrogen embrittlement in stainless steels

    Microsoft Academic Search

    Perng

    1985-01-01

    In order to understand the kinetics of gaseous hydrogen-induced slow crack growth (SCG) in metastable austenitic stainless steels, hydrogen permeation and\\/or cracking velocity were measured and compared for three types of stainless steels. These included austenitic, ferritic, and duplex (..gamma..\\/..cap alpha..) alloys. Deformation in AISI 301 resulted in various amounts of ..cap alpha..' martensite, which enhanced the effective hydrogen diffusivity

  3. Measurement of intergranular attack in stainless steel using ultrasonic energy

    DOEpatents

    Mott, Gerry (Pittsburgh, PA); Attaar, Mustan (Monroeville, PA); Rishel, Rick D. (Monroeville, PA)

    1989-08-08

    Ultrasonic test methods are used to measure the depth of intergranular attack (IGA) in a stainless steel specimen. The ultrasonic test methods include a pitch-catch surface wave technique and a through-wall pulse-echo technique. When used in combination, these techniques can establish the extent of IGA on both the front and back surfaces of a stainless steel specimen from measurements made on only one surface.

  4. In-reactor defomation and fracture of austenitic stainless steels

    Microsoft Academic Search

    E. E. Bloom; W. G. Wolfer

    1979-01-01

    An experimental technique for determining in-reactor fracture strain was developed and demonstrated. Differential swelling between a specimen holder and a test specimen with a lower swelling rate produced uniaxial deformation in 304 and cold-worked 316 stainless steel specimens. In-reactor deformations of 0.7 to 2.1% were achieved in Type 304 stainless steel previously irradiated to fluences up to 8.8 x 10²⁶

  5. Development of high strain rate equations for stainless steels

    NASA Astrophysics Data System (ADS)

    Andersson, R.; Syk, M.; Powell, J.; Magnusson, G.

    2005-10-01

    The dynamic response of four types of stainless steel sheet was investigated at different strain rates from 10-2 up to 103 s-1. The results from the tensile tests were used to evaluate the parameters in three different multiplicative strain rate equations of the type used in crashworthiness calculations. A new type of sigmoid constitutive equation is proposed for one grade of stainless steel.

  6. Procedure for flaw detection in cast stainless steel

    DOEpatents

    Kupperman, David S. (Oak Park, IL)

    1988-01-01

    A method of ultrasonic flaw detection in cast stainless steel components incorporating the steps of determining the nature of the microstructure of the cast stainless steel at the site of the flaw detection measurements by ultrasonic elements independent of the component thickness at the site; choosing from a plurality of flaw detection techniques, one such technique appropriate to the nature of the microstructure as determined and detecting flaws by use of the chosen technique.

  7. Tzvi Tzfira, Ph.D. Vitaly Citovsky, Ph.D.

    E-print Network

    Citovsky, Vitaly

    #12;Tzvi Tzfira, Ph.D. Vitaly Citovsky, Ph.D. Department of Biochemistry and Cell Biology State Bioscience / Eurekah.com, 810 South Church Street Georgetown, Texas, U.S.A. 78626 Phone: 512/ 863 7762; FAX selection and dosage and the specifications and usage of equipment and devices, as set forth in this book

  8. Ph.D. Mathematical Sciences Ph.D. Mathematical Sciences

    E-print Network

    Hemmers, Oliver

    Ph.D. Mathematical Sciences Program Ph.D. Mathematical Sciences Department(s) Mathematical Sciences. Number for later reference. 1. Students will have a broad understanding of several areas of mathematical to understand, analyze, create, and write mathematical proofs. 3. Students will be able to study and understand

  9. Ph.D. Physics Program Ph.D. in Physics

    E-print Network

    Hemmers, Oliver

    Ph.D. Physics Program Ph.D. in Physics Department(s) Physics and Astronomy College Sciences Program Assessment Coordinator Michael Pravica pravica@physics.unlv.edu 895-1723 Five-Year Implementation Dates (2010 for physics at the graduate level 4. understand statistical physics at the graduate level 5. perform

  10. Performance of ferritic stainless steels for automobile muffler corrosion

    SciTech Connect

    Tarutani, Y.; Hashizume, T. [Sumitomo Metal Industries Ltd., Amagasaki (Japan). Iron and Steel Research Lab.

    1995-11-01

    Corrosion behavior of ferritic stainless steels was studied in artificial exhaust gas condensates containing corrosive ions such as Cl{sup {minus}} and SO{sub 3}{sup 2{minus}}. Continuous immersion tests in flasks and Dip and Dry tests by using the alternate corrosion tester with a heating system clarified the effects of chromium and molybdenum additions on the corrosion resistance of a ferritic stainless steel in the artificial exhaust gas condensates. Effects of surface oxidation on the corrosion behavior were investigated in a temperature range of 573K to 673K. Oxidation of 673K reduced the corrosion resistance of the ferritic stainless steels in the artificial environment of the automobile muffler. Particulate matter deposited on the muffler inner shell from the automobile exhaust gas was also examined. Deposited particulate matter increased the corrosion rate of the ferritic stainless steel. Finally, the authors also investigated the corrosion of the automobile mufflers made of Type 436L ferritic stainless steel with 18% chromium-1.2% molybdenum after 24 months, in Japan. The sets of results clarified that Type 436L ferritic stainless steel as the material for the automobile muffler exhibited acceptable corrosion resistance.

  11. Solidification behavior of austenitic stainless steel filler metals

    SciTech Connect

    David, S.A.; Goodwin, G.M.; Braski, D.N.

    1980-02-01

    Thermal analysis and interrupted solidification experiments on selected austenitic stainless steel filler metals provided an understanding of the solidification behavior of austenitic stainless steel welds. The sequences of phase separations found were for type 308 stainless steel filler metal, L + L + delta + L + delta + ..gamma.. ..-->.. ..gamma.. + delta, and for type 310 stainless steel filler metal, L ..-->.. L + ..gamma.. ..-->.. ..gamma... In type 308 stainless steel filler metal, ferrite at room temperature was identified as either the untransformed primary delta-ferrite formed during the initial stages of solidification or the residual ferrite after Widmanstaetten austenite precipitation. Microprobe and scanning transmission electron microscope microanalyses revealed that solute extensively redistributes during the transformation of primary delta-ferrite to austenite, leading to enrichment and stabilization of ferrite by chromium. The type 310 stainless steel filler metal investigated solidifies by the primary crystallization of austenite, with the transformation going to completion at the solidus temperature. In our samples residual ferrite resulting from solute segregation was absent at the intercellular or interdendritic regions.

  12. X-ray attenuation properties of stainless steel (u)

    SciTech Connect

    Wang, Lily L [Los Alamos National Laboratory; Berry, Phillip C [Los Alamos National Laboratory

    2009-01-01

    Stainless steel vessels are used to enclose solid materials for studying x-ray radiolysis that involves gas release from the materials. Commercially available stainless steel components are easily adapted to form a static or a dynamic condition to monitor the gas evolved from the solid materials during and after the x-ray irradiation. Experimental data published on the x-ray attenuation properties of stainless steel, however, are very scarce, especially over a wide range of x-ray energies. The objective of this work was to obtain experimental data that will be used to determine how a poly-energetic x-ray beam is attenuated by the stainless steel container wall. The data will also be used in conjunction with MCNP (Monte Carlos Nuclear Particle) modeling to develop an accurate method for determining energy absorbed in known solid samples contained in stainless steel vessels. In this study, experiments to measure the attenuation properties of stainless steel were performed for a range of bremsstrahlung x-ray beams with a maximum energy ranging from 150 keV to 10 MeV. Bremsstrahlung x-ray beams of these energies are commonly used in radiography of engineering and weapon components. The weapon surveillance community has a great interest in understanding how the x-rays in radiography affect short-term and long-term properties of weapon materials.

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

    Microsoft Academic Search

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

    2007-01-01

    Corrosion tests of 1015 low-carbon steel and two stainless steels (410 and 316L) were conducted in a pure zinc bath (99.98wtpct\\u000a Zn) in order to better understand the reaction mechanisms that occur during the degradation of submerged hardware at industrial\\u000a general (batch) galvanizing operations. Through this testing, it was found that, in general, 316L stainless steel showed the\\u000a best dissolution

  14. An etched stainless steel wire/ionic liquid-solid phase microextraction technique for the determination of alkylphenols in river water.

    PubMed

    Cui, Meiyu; Qiu, Jinxue; Li, Zhenghua; He, Miao; Jin, Mingshi; Kim, Jiman; Quinto, Maurizio; Li, Donghao

    2015-01-01

    In this study, a stainless steel wire/ionic liquid-solid phase microextraction technique was developed for the direct extraction of APs from water samples. Some parameters were optimised, such as selection of the substrate and ILs, extraction time, extraction temperature, stirring rate and sample pH, etc. The experimental data demonstrated that the etched stainless steel wire was a suitable substrate for IL-coated SPME. The coating was prepared by directly depositing the ILs onto the surface of the etched stainless steel wire, which exhibited a porous structure and a high surface area. The [C8MIM][PF6] IL exhibited maximum efficiency with an extraction time of 30 min, and the aqueous sample was maintained at 40 C and adjusted to pH 2 under stirring conditions. The enrichment factor of the IL coating for the four APs ranged from 1382 to 4779, the detection limits (LOD, S/N=3) of the four APs ranged from 0.01 to 0.04 ng mL(-1) and the RSD values for purified water spiked with APs ranged from 4.0 to 11.8% (n=3). The calibration graphs were linear in the concentration range from 0.5 to 200 ng mL(-1) (R(2)>0.9569). The optimised method was successfully applied for the analysis of real water samples, and the method was suitable for the extraction of APs from water samples. PMID:25476345

  15. Phase Transformations in Cast Duplex Stainless Steels

    SciTech Connect

    Yoon-Jun Kim

    2004-12-19

    Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as {sigma} and {chi} can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase ({sigma} + {chi}) formation were analyzed using the Johnson-Mehl-Avrami (MA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities; a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, {sigma} was stabilized with increasing Cr addition and {chi} by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.

  16. The pH Game.

    ERIC Educational Resources Information Center

    Chemecology, 1996

    1996-01-01

    Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

  17. Jeanne Murhpy, PhD

    Cancer.gov

    Jeanne Murphy, PhD, CNM is a postdoctoral Cancer Prevention Fellow in the Breast and Gynecologic Cancer Research Group in the Division of Cancer Prevention. She comes to BGCRG with a PhD from Johns Hopkins University School of Nursing. She also completed a graduate certificate in Health Disparities and Health Inequality at Johns Hopkins Bloomberg School of Public Health.

  18. PH as a stress signal

    Microsoft Academic Search

    Sally Wilkinson

    1999-01-01

    The pH of the xylem sap of plants experiencing a range of environmental conditions can increase by over a whole pH unit. This results in an increased ABA concentration in the apoplast adjacent to the stomatal guard cells in the leaf epidermis, by reducing the ability of the mesophyll and epidermal symplast to sequester ABA away from this compartment. As

  19. Persistence of spiromesifen in soil: influence of moisture, light, pH and organic amendment.

    PubMed

    Mate, Ch Jamkhokai; Mukherjee, Irani; Das, Shaon Kumar

    2015-02-01

    Persistence of spiromesifen in soil as affected by varying moisture, light, compost amendment, soil sterilization and pH in aqueous medium were studied. Degradation of spiromesifen in soil followed the first-order reaction kinetics. Effect of different moisture regimes indicated that spiromesifen dissipated faster in submerged soil (t 1/2 14.3-16.7 days) followed by field capacity (t 1/2 18.7-20.0 days), and dry soil (t 1/2 21.9-22.9 days). Dissipation was faster in sterilized submerged (t 1/2 17.7 days) than in sterilized dry (t 1/2 35.8 days). Photo spiromesifen metabolite was not detected under different moisture regimes. After 30 days, enol spiromesifen metabolite was detected under submerged condition and was below detectable limit (<0.001 ?g g(-1)) after 90 days. Soil amendment compost (2.5 %) at field capacity enhanced dissipation of the insecticide, and half-life value was 14.3 against 22.4 days without compost amendment. Under different pH condition, residues persisted in water with half-life values 5.7 to 12.5 days. Dissipation in water was faster at pH 9.0 (t 1/2 5.7 days), followed by pH 4.0 (t 1/2 9.7 days) and pH 7.2 (t 1/2 12.5 days). Exposure of spiromesifen to different light conditions indicated that it was more prone to degradation under UV light (t 1/2 3-4 days) than sunlight exposure (t 1/2 5.2-8.1 days). Under sunlight exposure, photo spiromesifen metabolite was detected after 10 and 15 days as compared to 3 and 5 days under UV light exposure. PMID:25616783

  20. Welding Behavior of Free Machining Stainless Steel

    SciTech Connect

    BROOKS,JOHN A.; ROBINO,CHARLES V.; HEADLEY,THOMAS J.; MICHAEL,JOSEPH R.

    2000-07-24

    The weld solidification and cracking behavior of sulfur bearing free machining austenitic stainless steel was investigated for both gas-tungsten arc (GTA) and pulsed laser beam weld processes. The GTA weld solidification was consistent with those predicted with existing solidification diagrams and the cracking response was controlled primarily by solidification mode. The solidification behavior of the pulsed laser welds was complex, and often contained regions of primary ferrite and primary austenite solidification, although in all cases the welds were found to be completely austenite at room temperature. Electron backscattered diffraction (EBSD) pattern analysis indicated that the nature of the base metal at the time of solidification plays a primary role in initial solidification. The solid state transformation of austenite to ferrite at the fusion zone boundary, and ferrite to austenite on cooling may both be massive in nature. A range of alloy compositions that exhibited good resistance to solidification cracking and was compatible with both welding processes was identified. The compositional range is bounded by laser weldability at lower Cr{sub eq}/Ni{sub eq} ratios and by the GTA weldability at higher ratios. It was found with both processes that the limiting ratios were somewhat dependent upon sulfur content.

  1. Corrosion of stainless steel during acetate production

    SciTech Connect

    Qi, J.S.; Lester, G.C. [Occidental Chemical Corp. Technology Center, Grand Island, NY (United States)

    1996-07-01

    Corrosion of types 304, 304L, 316, and 316L stainless steel (SS) during the esterification of acetic acid and alcohol or glycol ether was investigated. The catalyst for this reaction, sulfuric acid or para-toluene sulfonic acid (PTSA), was shown to cause more corrosion on reactor equipment than CH{sub 3}COOH under the process conditions commonly practiced in industry. The corrosive action of the catalyst occurred only in the presence of water. Thus, for the batch processes, corrosion occurred mostly during the initial stage of esterification, where water produced by the reaction created an aqueous environment. After water was distilled off, the corrosion rate declined to a negligible value. The corrosion inhibitor copper sulfate, often used in industrial acetate processes, was found to work well for a low-temperature process (< 95 C) such as in production of butyl acetate, but it accelerated corrosion in the glycol ether acetate processes where temperatures were > 108 C. Process conditions that imparted low corrosion rates were determined.

  2. NanoComposite Stainless Steel Powder Technologies

    SciTech Connect

    DeHoff, R.; Glasgow, C. (MesoCoat, Inc.)

    2012-07-25

    Oak Ridge National Laboratory has been investigating a new class of Fe-based amorphous material stemming from a DARPA, Defense Advanced Research Projects Agency initiative in structural amorphous metals. Further engineering of the original SAM materials such as chemistry modifications and manufacturing processes, has led to the development of a class of Fe based amorphous materials that upon processing, devitrify into a nearly homogeneous distribution of nano sized complex metal carbides and borides. The powder material is produced through the gas atomization process and subsequently utilized by several methods; laser fusing as a coating to existing components or bulk consolidated into new components through various powder metallurgy techniques (vacuum hot pressing, Dynaforge, and hot isostatic pressing). The unique fine scale distribution of microstructural features yields a material with high hardness and wear resistance compared to material produced through conventional processing techniques such as casting while maintaining adequate fracture toughness. Several compositions have been examined including those specifically designed for high hardness and wear resistance and a composition specifically tailored to devitrify into an austenitic matrix (similar to a stainless steel) which poses improved corrosion behavior.

  3. 76 FR 38688 - Certain Welded Stainless Steel Pipe From Korea and Taiwan; Institution of a Five-Year Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ...Register Volume 76, Number 127 (Friday...Welded Stainless Steel Pipe From Korea...welded stainless steel pipe from Korea...Budget (OMB) number is not displayed; the OMB number is 3117-0016...A-312 stainless steel pipe from...

  4. 77 FR 18861 - Stainless Steel Bar From Brazil, India, Japan, and Spain; Scheduling of Expedited Five-Year Reviews

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-28

    ...679, 681, and 682 (Third Review)] Stainless Steel Bar From Brazil, India, Japan...revocation of the antidumping duty orders on stainless steel bar from Brazil, India, Japan...O. Carlson Inc. Co., Universal Stainless & Alloy Products, Inc., and...

  5. 78 FR 72864 - Drawn Stainless Steel Sinks From the People's Republic of China: Initiation of New Shipper Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ...Administration [A-570-983] Drawn Stainless Steel Sinks From the People's Republic...of the antidumping duty order on drawn stainless steel sinks (``drawn sinks'') from...1\\ See Drawn Stainless Steel Sinks from the People's...

  6. 78 FR 34337 - Stainless Steel Bar From India: Final Results of Antidumping Duty Administrative Review; 2011-2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ...Trade Administration [A-533-810] Stainless Steel Bar From India: Final Results...review of the antidumping duty order on stainless steel bar from India (Preliminary Results...1\\ See Stainless Steel Bar from India: Preliminary...

  7. 76 FR 45511 - Stainless Steel Plate in Coils From Belgium: Notice of Initiation of Antidumping Duty Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ...Administration [A-423-808] Stainless Steel Plate in Coils From Belgium...of the antidumping duty order on stainless steel plate in coils (``SSPC...from Belgium with respect to Aperam Stainless Belgium N.V....

  8. 78 FR 22227 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review; 2011-2012

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ...Trade Administration [A-351-825] Stainless Steel Bar From Brazil: Final Results...review of the antidumping duty order on stainless steel bar (SSB) from Brazil. For these...1\\ See Stainless Steel Bar From Brazil: Preliminary...

  9. 77 FR 24459 - Stainless Steel Butt-Weld Pipe Fittings From Italy: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    ...Trade Administration [A-475-828] Stainless Steel Butt-Weld Pipe Fittings From...review of the antidumping duty order on stainless steel butt-weld pipe fittings (SSBW...1\\ See Stainless Steel Butt-Weld Pipe Fittings...

  10. 76 FR 66271 - Stainless Steel Plate in Coils From Belgium: Notice of Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ...Trade Administration [A-423-808] Stainless Steel Plate in Coils From Belgium: Notice...request from the interested party, Aperam Stainless Belgium N.V. (``Aperam...of the antidumping duty order of stainless steel plate in coils...

  11. Pitting corrosion detection of austenitic stainless steel EN 1.4404 in MgCl2 solutions using a machine learning approach

    NASA Astrophysics Data System (ADS)

    Jimnez-Come, M. J.; Muoz, E.; Garca, R.; Matres, V.; Martn, M. L.; Trujillo, F.; Turias, I.

    2012-04-01

    Different classification techniques such as Classification Tree (CT), Discriminant Analysis (DA), K-Nearest Neighbour (KNN) and Back-Propagation Neural Networks (BPNN) have been used to model pitting corrosion behaviour of austenitic stainless steel EN 1.4404. The main purpose is to predict the corrosion status of this material in different environmental conditions. Samples of this alloy have been subjected to polarization tests in order to determine pitting potentials values (Epit) with different aqueous conditions: chloride concentration (from MgCl2 solutions), pH values and temperature. In this way, the classification methods employed try to simulate the relation between corrosion status and those various environmental parameters studied. These techniques have generally been regarded as successful, giving a good correlation between experimental and predicted data. High values for precision have been obtained for all the models making these techniques an useful tool to know the behaviour of austenitic stainless steel in different environmental conditions.

  12. Corrosion behavior of ferritic stainless steel with 15wt% chromium for the automobile exhaust system

    NASA Astrophysics Data System (ADS)

    Li, Hua-bing; Jiang, Zhou-hua; Feng, Hao; Zhu, Hong-chun; Sun, Bin-han; Li, Zhen

    2013-09-01

    The effect of chloride ion concentration, pH value, and grain size on the pitting corrosion resistance of a new ferritic stainless steel with 15wt% Cr was investigated using the anodic polarization method. The semiconducting properties of passive films with different chloride ion concentrations were performed using capacitance measurement and Mott-Schottky analysis methods. The aging precipitation and intergranular corrosion behavior were evaluated at 400-900C. It is found that the pitting potential decreases when the grain size increases. With the increase in chloride ion concentration, the doping density and the flat-bland potential increase but the thickness of the space charge layer decreases. The pitting corrosion resistance increases rapidly with the decrease in pH value. Precipitants is identified as Nb(C,N) and NbC, rather than Cr-carbide. The intergranular corrosion is attributed to the synergistic effects of Nb(C,N) and NbC precipitates and Cr segregation adjacent to the precipitates.

  13. Machining-induced deformation in stepped specimens of PH 13-8 Mo, 18 nickel maraging steel grade 200T1 and grain-refined HP 9-4-20

    NASA Technical Reports Server (NTRS)

    Wigley, D. A.

    1985-01-01

    The results of a study to evaluate the dimensional changes created during machining and subsequent cycling to cryogenic temperatures for three different metallic alloys are presented. Experimental techniques are described and results presented for 18 Ni Grade 200 maraging steel, PH-13-8 Mo stainless steel, and Grain-refined HP 9-4-20.

  14. Aging of cast duplex stainless steels in LWR systems

    SciTech Connect

    Chopra, O.K.; Chung, H.M.

    1984-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. The existing data are evaluated to determine the expected embrittlement of cast components during the operating lifetime of reactors and to define the objectives and scope of the investigation. This presentation describes the status of the program. Data for the metallurgical characterization of the various cast stainless steels used in the investigation are presented. Charpy impact tests on short-term aged material indicate that CF-3 stainless steels are less susceptible to embrittlement than CF-8 or CF-8M stainless steels. Microstructural characterization of cast stainless steels that were obtained from Georg Fischer Co. and aged for up to 70,000 h at 300, 350, and 400/sup 0/C reveals the formation of four different types of precipitates that are not ..cap alpha..'. Embrittlement of the ferrite phase is primarily due to pinning of the dislocations by two of these precipitates, designated as Type M and Type X. The ferrite phase is embrittled after approx. 8 y at 300/sup 0/C and shows cleavage fracture. Examination of the fracture surfaces of the impact-test specimens indicates that the toughness of the long-term aged material is determined by the austenite phase. 8 figures, 3 tables.

  15. Work of adhesion of dairy products on stainless steel surface

    PubMed Central

    Bernardes, Patrcia Campos; Arajo, Emiliane Andrade; dos Santos Pires, Ana Clarissa; Queiroz Fialho Jnior, Jos Felcio; Lelis, Carini Aparecida; de Andrade, Nlio Jos

    2012-01-01

    The adhesion of the solids presents in food can difficult the process of surface cleaning and promotes the bacterial adhesion process and can trigger health problems. In our study, we used UHT whole milk, chocolate based milk and infant formula to evaluate the adhesion of Enterobacter sakazakii on stainless steel coupons, and we determine the work of adhesion by measuring the contact angle as well as measured the interfacial tension of the samples. In addition we evaluated the hydrophobicity of stainless steel after pre-conditioning with milk samples mentioned. E. sakazakii was able to adhere to stainless steel in large numbers in the presence of dairy products. The chocolate based milk obtained the lower contact angle with stainless steel surface, higher interfacial tension and consequently higher adhesion work. It was verified a tendency of decreasing the interfacial tension as a function of the increasing of protein content. The preconditioning of the stainless steel coupons with milk samples changed the hydrophobic characteristics of the surfaces and became them hydrophilic. Therefore, variations in the composition of the milk products affect parameters important that can influence the procedure of hygiene in surface used in food industry. PMID:24031951

  16. Investigation of the diffusion kinetics of borided stainless steels

    NASA Astrophysics Data System (ADS)

    Kayali, Yusuf

    2013-12-01

    In this study, the kinetics of borides formed on AISI 420, AISI 304 and AISI 304L stainless steels was investigated. Boronizing treatment was carried out using Ekabor-II powders at the processing temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The phases of the boride layers of borided AISI 420, AISI 304 and AISI 304L stainless steels were FeB, Fe2B, CrB and NiB, respectively. The thickness of the boride layer formed on the borided steels ranged from 4.6 to 64 ?m depending on the boriding temperature, boriding time and alloying elements of the stainless steels. Depending on the chemical composition, temperature and layer thickness, the activation energies of boron in AISI 420, AISI 304 and AISI 304L stainless steels were found to be 206.161, 234.641 and 222.818 kJ/mol, respectively. The kinetics of growth of the boride layers formed on the AISI 420, AISI 304 and AISI 304L stainless steels and the thickness of the boride layers were investigated.

  17. Aluminum and stainless steel tubes joined by simple ring and welding process

    NASA Technical Reports Server (NTRS)

    Townhill, A.

    1967-01-01

    Duranel ring is used to join aluminum and stainless steel tubing. Duranel is a bimetal made up of roll-bonded aluminum and stainless steel. This method of joining the tubing requires only two welding operations.

  18. 75 FR 973 - Certain Welded Stainless Steel Pipes From the Republic of Korea: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-07

    ...Certain Welded Stainless Steel Pipes From the Republic of Korea: Preliminary Results of Antidumping Duty Administrative...welded stainless steel pipes (WSSP) from the Republic of Korea (Korea) for the period of review (POR) December 1, 2007...

  19. The hardening of Type 316L stainless steel welds with thermal aging

    E-print Network

    Ayers, Lauren Juliet

    2012-01-01

    Welded stainless steel piping is a component of boiling water reactors (BWRs). Reirculation and other large diameter piping are fabricated from Type 304 or 316 stainless steels. Delta ferrite is present in welds, because ...

  20. 78 FR 79667 - Stainless Steel Sheet and Strip in Coils From Japan: Initiation of Expedited Changed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ...length. Certain stainless steel foil for automotive catalytic converters is also excluded from the scope of this order. This stainless...with a honeycomb structure for use in automotive catalytic converters. The steel contains, by weight, carbon of no more...

  1. 75 FR 70908 - Circular Welded Austenitic Stainless Pressure Pipe From the People's Republic of China: Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ...Administration [A-570-930] Circular Welded Austenitic Stainless Pressure Pipe From the People's Republic of China: Extension of the...antidumping duty order on circular welded austenitic stainless pressure pipe from the People's Republic of China. See...

  2. 78 FR 31574 - Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ...731-TA-1210-1212 (Preliminary)] Welded Stainless Steel Pressure Pipe From Malaysia, Thailand, and Vietnam; Institution of...Malaysia, Thailand, and Vietnam of welded stainless steel pressure pipe, provided for in in subheadings 7306.40.50 and...

  3. David Cheresh, PhD

    Cancer.gov

    Meetings & Events Home Agenda Speaker Biosketches Abstracts Logistics Contact Speaker Biosketches David Cheresh, PhD(University of California, San Diego) Dr. David Cheresh studies the mechanism of action of signaling networks that regulate

  4. Esophageal pH monitoring

    MedlinePLUS

    pH monitoring - esophageal; Esophageal acidity test ... esophagitis You may need to have the following tests if your doctor suspects esophagitis : Barium swallow Esophagogastroduodenoscopy (also called upper GI endoscopy)

  5. A peptide stainless steel reaction that yields a new bioorganic metal state of matter

    Microsoft Academic Search

    Elisabeth M. Davis; Dong-yang Li; Randall T. Irvin

    2011-01-01

    A synthetic peptide derived from the native protein sequence of a metal binding bacterial pilus was observed to spontaneously react with stainless steel via a previously unreported type of chemical interaction to generate an altered form of stainless steel which we term bioorganic stainless steel. Bioorganic stainless steel has a significantly increased electron work function (4.90.05eV compared to 4.790.07eV), decreased

  6. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Microsoft Academic Search

    Songqing Wen; Carl Lundin; Greg Batten

    2005-01-01

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. ;\\u000a\\u0009Selected grades of duplex stainless steel castings and their welds, in

  7. Bacterial adhesion on ion-implanted stainless steel surfaces

    NASA Astrophysics Data System (ADS)

    Zhao, Q.; Liu, Y.; Wang, C.; Wang, S.; Peng, N.; Jeynes, C.

    2007-08-01

    Stainless steel disks were implanted with N +, O + and SiF 3+, respectively at the Surrey Ion Beam Centre. The surface properties of the implanted surfaces were analyzed, including surface chemical composition, surface topography, surface roughness and surface free energy. Bacterial adhesion of Pseudomonas aeruginosa, Staphylococcus epidermidis and Staphylococcus aureus, which frequently cause medical device-associated infections was evaluated under static condition and laminar flow condition. The effect of contact time, growth media and surface properties of the ion-implanted steels on bacterial adhesion was investigated. The experimental results showed that SiF 3+-implanted stainless steel performed much better than N +-implanted steel, O +-implanted steel and untreated stainless steel control on reducing bacterial attachment under identical experimental conditions.

  8. Corrosion in lithium-stainless steel thermal-convection systems

    SciTech Connect

    Tortorelli, P.F.; DeVan, J.H.; Selle, J.E.

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650/sup 0/C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop.

  9. Machinability of a Stainless Steel by Electrochemical Discharge Microdrilling

    SciTech Connect

    Coteata, Margareta; Pop, Nicolae; Slatineanu, Laurentiu ['Gheorghe Asachi' Technical University of Iasi, Department of Machine Manufacturing Technology, Blvd. D Mangeron 59A, 700050 Iasi (Romania); Schulze, Hans-Peter [Otto-von-Guericke-University Magdeburg, Institute of Fundamental Electrical Engineering and EMC Universitaetsplatz 2, D-39106 Magdeburg (Germany); Besliu, Irina [University 'Stefan cel Mare' of Suceava, Department of Technologies and Management, Str. Universitatii, 13, 720 229 Suceava (Romania)

    2011-05-04

    Due to the chemical elements included in their structure for ensuring an increased resistance to the environment action, the stainless steels are characterized by a low machinability when classical machining methods are applied. For this reason, sometimes non-traditional machining methods are applied, one of these being the electrochemical discharge machining. To obtain microholes and to evaluate the machinability by electrochemical discharge microdrilling, test pieces of stainless steel were used for experimental research. The electrolyte was an aqueous solution of sodium silicate with different densities. A complete factorial plan was designed to highlight the influence of some input variables on the sizes of the considered machinability indexes (electrode tool wear, material removal rate, depth of the machined hole). By mathematically processing of experimental data, empirical functions were established both for stainless steel and carbon steel. Graphical representations were used to obtain more suggestive vision concerning the influence exerted by the considered input variables on the size of the machinability indexes.

  10. Rapid heating tensile testing update: 304L stainless steel

    SciTech Connect

    Mosley, W.C.

    1993-08-01

    In stainless steel equipment exposed to tritium, embrittlement is thought to involve interactions between internal He and the complex triaxial stress state that arises when necking starts. Recent efforts have been directed at determining He concentration thresholds for this effect in several austenitic stainless steels. This report describes results of tests on 304L stainless steel containing low He-3 contents. 304L ss containing 0.47 and 4.1 appM He-3 tested at 803--814{degrees}C had lower tensile properties than uncharged samples. Mechanical properties were not affected by 0.47 appM at 615{degrees}C but ductility was severely decreased at 810{degrees}C.

  11. Electrochemical behaviour of AISI316 stainless steels in sulphuric\\/nitric acid mixtures

    Microsoft Academic Search

    Inder Singh; A. K. Bhattamishra; D. K. Basu

    1997-01-01

    Stainless steels are very unique in that they offer a wide range and combination of resistance to corrosion, resistance to oxidation at high temperature and good mechanical properties at room temperature. With rapid industrialization all over the world, these very properties have led to extensive use of stainless steels in different industries. Austenitic stainless steels containing molybdenum exhibit corrosion resistance

  12. Improved Accident Tolerance of Austenitic Stainless Steel Cladding through Colossal Supersaturation with Interstitial Solutes

    E-print Network

    Cavusoglu, Cenk

    Improved Accident Tolerance of Austenitic Stainless Steel Cladding through Colossal Supersaturation stainless steels, which have significantly better oxidation resistance under accident conditions. However, they are prone to SCC (stress-corrosion cracking). Our goal is to improve the properties of austenitic stainless

  13. Corrosion and mechanical properties of duplex-treated 301 stainless steel

    Microsoft Academic Search

    M. Azzi; M. Benkahoul; J. E. Klemberg-Sapieha; L. Martinu

    2010-01-01

    Plasma nitriding is a widely used technique for increasing the surface hardness of stainless steels, and consequently, for improving their tribological properties. It is also used to create an interface between soft stainless steel substrates and hard coatings to improve adhesion. This paper reports on the mechanical and corrosion properties of AISI301 stainless steel (SS) after a duplex treatment consisting

  14. 77 FR 60478 - Control of Ferrite Content in Stainless Steel Weld Metal

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ...Register Volume 77, Number 192 (Wednesday, October...Content in Stainless Steel Weld Metal AGENCY: Nuclear...Content in Stainless Steel Weld Metal,'' is temporarily...identified by its task number, DG-1279. The DG-1279...content in stainless steel weld metal. This...

  15. 75 FR 30434 - Stainless Steel Plate From Belgium, Italy, Korea, South Africa, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ...Register Volume 75, Number 104 (Tuesday, June...Review)] Stainless Steel Plate From Belgium...duty orders on stainless steel plate from Belgium and...duty orders on stainless steel plate from Belgium...Management and Budget (OMB) number is not displayed;...

  16. 75 FR 30437 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-01

    ...Register Volume 75, Number 104 (Tuesday, June...Review)] Stainless Steel Sheet and Strip From...duty order on stainless steel sheet and strip from...duty orders on stainless steel sheet and strip from...Management and Budget (OMB) number is not displayed;...

  17. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    Microsoft Academic Search

    Ayo Samuel AFOLABI; K. K. ALANEME; Samson Oluwaseyi BADA

    2009-01-01

    The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the

  18. 78 FR 4383 - Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty Administrative Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ...A-351-825] Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty...order on stainless steel bar (SSB) from Brazil. The period of review (POR) is February...Administrative Review: Stainless Steel Bar from Brazil'' dated concurrently with this...

  19. Fabrication of 316-L stainless steel micro components using encapsulating soft mould and isopressing technique

    Microsoft Academic Search

    M. Imbaby; K. Jiang; I. Chang

    2010-01-01

    This paper presents in detail a new method to fabricate free standing 316-L stainless steel micro components using high solid loading stainless steel semi solid paste encapsulated into soft mould (PDMS) and pressed using hydrostatic pressure. The process is divided into five parts: (i) production of SU-8 master moulds and their negative replicas from soft moulds, (ii) preparation of stainless

  20. 77 FR 39467 - Stainless Steel Bar From India: Final Results of the Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ...Trade Administration [A-533-810] Stainless Steel Bar From India: Final Results...review of the antidumping duty order on stainless steel bar from India. The review covers...March 6, 2012, the Department published Stainless Steel Bar From India: Preliminary...

  1. 75 FR 12514 - Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ...Trade Administration [A-351-825] Stainless Steel Bar From Brazil: Preliminary Results...the antidumping duty order on certain stainless steel bar from Brazil. The review covers...an antidumping duty order on certain stainless steel bar from Brazil. See...

  2. 76 FR 18518 - Stainless Steel Sheet and Strip in Coils From Mexico: Rescission of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ...Trade Administration [A-201-822] Stainless Steel Sheet and Strip in Coils From Mexico...of the antidumping duty order covering stainless steel sheet and strip in coils from Mexico...Allegheny Ludlum Corporation, North American Stainless, and AK Steel Corporation...

  3. 76 FR 1599 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-11

    ...Trade Administration [A-351-825] Stainless Steel Bar From Brazil: Final Results...review of the antidumping duty order on stainless steel bar from Brazil. The review covers...review of the antidumping duty order on stainless steel bar (SSB) from Brazil. See...

  4. 78 FR 34644 - Stainless Steel Plate in Coils From Belgium: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ...Trade Administration [A-423-808] Stainless Steel Plate in Coils From Belgium: Preliminary...review of the antidumping duty order on stainless steel plate in coils (steel plate...exporter of the subject merchandise, Aperam Stainless Belgium N.V. (ASB). We have...

  5. 78 FR 79662 - Stainless Steel Plate in Coils From Belgium: Final Results of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-31

    ...Trade Administration [A-423-808] Stainless Steel Plate in Coils From Belgium: Final...antidumping duty administrative review on stainless steel plate in coils (steel plate...exporter of the subject merchandise: Aperam Stainless Belgium N.V. (ASB). The...

  6. 75 FR 53714 - Stainless Steel Butt-Weld Pipe Fittings From Japan, Korea, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ...731-TA-376, 563, and 564 (Third Review)] Stainless Steel Butt-Weld Pipe Fittings From...concerning the antidumping duty orders on stainless steel butt-weld pipe fittings from...revocation of the antidumping duty orders on stainless steel butt-weld pipe fittings...

  7. 75 FR 39663 - Stainless Steel Bar From Brazil: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ...Trade Administration [A-351-825] Stainless Steel Bar From Brazil: Final Results...the antidumping duty order on certain stainless steel bar from Brazil. The review covers...the antidumping duty order on certain stainless steel bar from Brazil. See...

  8. 75 FR 81217 - Stainless Steel Plate in Coils From Belgium: Preliminary Results of Full Sunset Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ...Trade Administration [C-423-809] Stainless Steel Plate in Coils From Belgium: Preliminary...duty (``CVD'') order on certain stainless steel plate in coils from Belgium...substantive responses from ArcelorMittal Stainless Belgium N.V. (``AMS'') and...

  9. 75 FR 67689 - Stainless Steel Bar From Brazil: Preliminary Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-03

    ...Trade Administration [A-351-825] Stainless Steel Bar From Brazil: Preliminary Results...the antidumping duty order on certain stainless steel bar from Brazil. The review covers...an antidumping duty order on certain stainless steel bar from Brazil. See...

  10. Susceptibility of stainless steel alloys to crevice corrosion in ClO 2 bleach plants

    Microsoft Academic Search

    Gustaf Bck; Preet M Singh

    2004-01-01

    Stainless steels, including duplex stainless steels, are extensively used for equipment in pulp bleaching plants. One serious corrosion problem in chlorine dioxide bleach plants is crevice corrosion of stainless steels, which is frequently the factor that limits their use in bleach plants. Crevice corrosion susceptibility of alloys depends on various environmental factors including temperature, chemical composition of environment and resulting

  11. The effect of permeated hydrogen on the pitting of type 304 stainless steel

    Microsoft Academic Search

    H. Yashiro; B. Pound; N. Kumagai; K. Tanno

    1998-01-01

    The effect of permeated hydrogen on the pitting behavior of type 304 stainless steel was investigated using a Devanathan type cell. One side of the stainless steel sheet was galvanostatically charged with hydrogen, while the other side was subjected to pitting tests. The permeated hydrogen typically enhanced the pitting susceptibility of the stainless steel; the pitting potential during potentiodynamic polarization

  12. 76 FR 46323 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ...Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and...on stainless steel sheet and strip from Germany, Italy, and Mexico \\2\\ would not be...to stainless steel sheet and strip from Germany, Italy, and Mexico, and...

  13. "Ceramics and high-temperature composites, silicides" Oxidation of Stainless Steel Powder

    E-print Network

    Paris-Sud XI, Universit de

    "Ceramics and high-temperature composites, silicides" CHTC9 Oxidation of Stainless Steel Powder. To understand the corrosion behavior of a model 304L(p)-ZrO2(s) composite, a 304L stainless steel powder has stainless steel particles. In this domain a mechanism is proposed and the kp value is calculated both due

  14. 75 FR 54090 - Stainless Steel Bar From India: Final Results of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ...A-533-810] Stainless Steel Bar From India: Final Results of Antidumping Duty Administrative...stainless steel bar (``SSB'') from India for the period February 1, 2008, through...31, 2009. See Stainless Steel Bar From India: Preliminary Results of Antidumping...

  15. 77 FR 41969 - Stainless Steel Bar From Japan: Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-17

    ...Administration [A-588-833] Stainless Steel Bar From Japan: Rescission of Antidumping Duty...antidumping duty order on stainless steel bar from Japan (the Order) covering the period...Suruga to the Secretary, ``Stainless Steel Bar--Withdrawal of Request for...

  16. Influence of excess phases on corrosion behavior of stainless steels

    SciTech Connect

    Knyazheva, V.M.; Babich, S.G.; Kolotyrkin, Y.M.

    1985-11-01

    The authors discuss the corrosion-electrochemical properties of titanium carbide, niobium carbide, the carbides of chromium (including alloyed ones), the nitride Cr(2)N, etc. When present as excess phases, these compounds of the transition metals can exert a marked influence on the corrosion behavior of stainless steels. This influence can be either beneficial or detrimental according to the oxidation-reduction properties of the medium. It is shown that scientifically based regulation of the macrostructure of steels with allowance for their intended applications is a good way of increasing the corrosion resistance of stainless steels.

  17. Anisotropy of nickel release and corrosion in austenitic stainless steels.

    PubMed

    Reclaru, L; Lthy, H; Ziegenhagen, R; Eschler, P-Y; Blatter, A

    2008-05-01

    The study of 316L-type stainless steel reveals a significant anisotropy of nickel release that is dependent on the orientation of the test surface with respect to the casting and rolling direction. Cross-sectional specimens (transversal cuts with respect to the rolling direction) show a substantially higher sensitivity to corrosion phenomena compared with longitudinal cuts and they release nickel ions at rates 10-100 times higher. These findings indicate that orientation needs to be taken into account when interpreting test results, in particular when comparing different grades of austenitic stainless steel, as well as in product and production design. PMID:18054530

  18. From flint to stainless steel: observations on surgical instrument composition.

    PubMed Central

    Kirkup, J.

    1993-01-01

    Man's failure to extract deeply embedded thorns and arrowheads, with bare hands and teeth, stimulated 'instrument substitutes' mimicking these appendages. Evidence from primitive communities suggest animal, plant and mineral items were employed, both before and after metal became the standard material of today's armamentarium. Changing surgical instrument composition has mirrored concurrent technology and manufacturing methods both of which are reviewed. Particular significance is accorded flint, bronze, crucible steel, thermal sterilisation, nickel-plate, stainless steel and disposable plastics. The paper is based on an exhibition From Flint to Stainless Steel on display at the College. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8215156

  19. Corrosion evaluation of stainless steel root weld shielding

    SciTech Connect

    Gorog, M.; Sawyer, L.A.

    1999-07-01

    The effect of five shielding methods for gas tungsten arc root pass welds, on the corrosion resistance of stainless steel was evaluated in two laboratory solutions. The first experiment was performed in 6% ferric chloride solution, a test designed to corrode stainless steel. The second experiment was performed in a simulated paper machine white water solution that contained hydrogen peroxide. Argon shielding produced excellent results by maintaining corrosion resistance in both solutions. Nitrogen purging and flux coated TIG rod techniques produced variable results. Paste fluxes and welding without shielding are not recommended for root protection. They performed very poorly with the welds corroding in both tests.

  20. B.S. to Ph.D. M.S. to Ph.D. Dual-title Ph.D.

    E-print Network

    -centered care For More Information Marsha Freije, M.S.N. Graduate Adviser College of Nursing The PennsylvaniaPh.D. in Nursing B.S. to Ph.D. · M.S. to Ph.D. Dual-title Ph.D. (Nursing and Bioethics) Become a part of Penn State's vibrant research enterprise in nursing science Partner with nationally renowned

  1. Effect of nitrogen on corrosion behavior of 28Cr7Ni duplex and microduplex stainless steels in air-saturated 3.5 wt% NaCl solution

    Microsoft Academic Search

    G. Lothongkum; P. Wongpanya; S. Morito; T. Furuhara; T. Maki

    2006-01-01

    The corrosion behavior of 28Cr7NiO0.34N duplex stainless steels in air-saturated 3.5-wt% NaCl solution at pH 2, 7, 10 and 27 C was studied by the potentiodynamic method. Two types of microstructures were investigated: the as-forged duplex and microduplex (average austenite grain size 516 ?m) structures. The austenite volume fractions of the tested steels were between 0.35 and 0.64. The nitrogen

  2. Super austenitic stainless steels a promising replacement for the currently used type 316L stainless steel as the construction material for flue-gas desulphurization plant

    Microsoft Academic Search

    N. Rajendran; S. Rajeswari

    1996-01-01

    Potentiodynamic anodic cyclic polarization experiments on type 316L stainless steel and 6Mo super austenitic stainless steels were carried out in simulated flue-gas desulphurization (FGD) environment in order to assess the localized corrosion resistance. The pitting corrosion resistance was higher in the case of the super austenitic stainless steel containing 6Mo and a higher amount of nitrogen. The pit-protection potential of

  3. The dimensional stability analysis of seventeen stepped specimens of 18Ni 200 grade, PH13-8Mo and A-286

    NASA Technical Reports Server (NTRS)

    Wigley, D. A.

    1983-01-01

    This report documents the results of a dimensional stability analysis of seventeen stepped specimens that were used in the evaluation of factors influencing warpage in metallic alloys being used for cryogenic wind tunnel models. Specimens used in the analysis were manufactured from 18Ni 200 Grade Maaraging steel, PH13-8Mo, and A-286 stainless steel. Quantitative data are provided on the behavior of the specimens due to the effects of both machining and cryogenic cycling effects.

  4. Rutherford backscattering analysis of gallium implanted 316 stainless steel

    E-print Network

    Ortensi, Javier

    2000-01-01

    Ion implantation of Ga ions into 316 stainless steel was performed at fluences ranging from 8x10? to 10? ions/cm. The depth profile of Ga in the steel was analyzed via Rutherford Backscattering and ToFSIMS. The surface effects were...

  5. Work-hardening in the drilling of austenitic stainless steels

    Microsoft Academic Search

    S Dolinek

    2003-01-01

    Due to specific properties arising from their structure (high toughness, work-hardening, low heat conductivity) austenitic stainless steels belong to the group of materials that are difficult to machine. Drilling of these steels is even more difficult as it is not easy to follow the cutting process going on at the drill tip. The paper presents an experimental investigation of the

  6. Neural network model of creep strength of austenitic stainless steels

    E-print Network

    Cambridge, University of

    Neural network model of creep strength of austenitic stainless steels T. Sourmail, H. K. D. H, and solution treatment temperature. The method involved a neural network analysis of a vast and general, and stress. Neural networks represent a more general regression method, which ameliorates most

  7. Microstructural Development during Solidification of Stainless Steel Alloys

    E-print Network

    Eagar, Thomas W.

    ) Microstructural Development during Solidification of Stainless Steel Alloys J.W. ELMER, S alloys are related to the solidification conditions and the specific alloy composition and the chemical composition of the alloy both influence (I) the primary mode of solidification, (2) solute

  8. Characterisation of passive films on 300 series stainless steels

    Microsoft Academic Search

    T. L. Sudesh L. Wijesinghe; D. J. Blackwood

    2006-01-01

    The formation and breakdown of the passive films on stainless steels are mainly controlled by ionic and electronic transport processes. Both these processes are in part controlled by the electronic properties of the oxide film. Consequently, it is vital to gain a detailed perception of the electronic properties of the passive films together with structural and compositional information for a

  9. Stress corrosion cracking of duplex stainless steels in caustic solutions

    Microsoft Academic Search

    Ananya Bhattacharya

    2008-01-01

    Duplex stainless steels (DSS) with roughly equal amount of austenite and ferrite phases are being used in industries such as petrochemical, nuclear, pulp and paper mills, de-salination plants, marine environments, and others. However, many DSS grades have been reported to undergo corrosion and stress corrosion cracking in some aggressive environments such as chlorides and sulfide-containing caustic solutions. Although stress corrosion

  10. Potentiodynamic studies of stainless steel wire for endourology

    Microsoft Academic Search

    J. Przondziono; W. Walke

    Purpose: The purpose of the study is to evaluate resistance to electrochemical corrosion of wire made of Cr- Ni stainless steel, designed for use in endourological treatment. The influence of strain formed in the process of drawing and methods of wire surface preparation to corrosive resistance in artificial urine solution were analysed. Design\\/methodology\\/approach: Wire corrosion tests were carried out in

  11. Simplified Estimation of Tritium Inventory in Stainless Steel

    SciTech Connect

    Willms, R. Scott [Los Alamos National Laboratory (United States)

    2005-07-15

    An important part of tritium facility waste management is estimating the residual tritium inventory in stainless steel. This was needed as part of the decontamination and decommissioning associated with the Tritium Systems Test Assembly at Los Alamos National Laboratory. In particular, the disposal path for three, large tanks would vary substantially depending on the tritium inventory in the stainless steel walls. For this purpose the time-dependant diffusion equation was solved using previously measured parameters. These results were compared to previous work that measured the tritium inventory in the stainless steel wall of a 50-L tritium container. Good agreement was observed. These results are reduced to a simple algebraic equation that can readily be used to estimate tritium inventories in room temperature stainless steel based on tritium partial pressure and exposure time. Results are available for both constant partial pressure exposures and for varying partial pressures. Movies of the time dependant results were prepared which are particularly helpful for interpreting results and drawing conclusions.

  12. Alternative to Nitric Acid for Passivation of Stainless Steel Alloys

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L.; Kolody, Mark; Curran, Jerry

    2013-01-01

    Corrosion is an extensive problem that affects the Department of Defense (DoD) and National Aeronautics and Space Administration (NASA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. Consequently, it is vital to reduce corrosion costs and risks in a sustainable manner. The DoD and NASA have numerous structures and equipment that are fabricated from stainless steel. The standard practice for protection of stainless steel is a process called passivation. Typical passivation procedures call for the use of nitric acid; however, there are a number of environmental, worker safety, and operational issues associated with its use. Citric acid offers a variety of benefits including increased safety for personnel, reduced environmental impact, and reduced operational cost. DoD and NASA agreed to collaborate to validate citric acid as an acceptable passivating agent for stainless steel. This paper details our investigation of prior work developing the citric acid passivation process, development of the test plan, optimization of the process for specific stainless steel alloys, ongoing and planned testing to elucidate the process' resistance to corrosion in comparison to nitric acid, and preliminary results.

  13. Failure Assessment Diagram for Brazed 304 Stainless Steel Joints

    NASA Technical Reports Server (NTRS)

    Flom, Yory

    2011-01-01

    Interaction equations were proposed earlier to predict failure in Albemet 162 brazed joints. Present study demonstrates that the same interaction equations can be used for lower bound estimate of the failure criterion in 304 stainless steel joints brazed with silver-based filler metals as well as for construction of the Failure Assessment Diagrams (FAD).

  14. Saturation in ``nonmagnetic'' stainless steel C. Weber and J. Fajansa)

    E-print Network

    Fajans, Joel

    with the strength of the field, causing it to be effectively nonmagnetic in fields much greater than its saturation/4 in. long 1/4-20 304 stainless steel bolts, sold by Lesker4 for vacuum flanges. The bolt threads' permeability was about 1.2, and the bolt heads' permeability ranged up to 1.8. All samples were separated

  15. Paraequilibrium Carburization of Duplex and Ferritic Stainless Steels

    NASA Astrophysics Data System (ADS)

    Michal, G. M.; Gu, X.; Jennings, W. D.; Kahn, H.; Ernst, F.; Heuer, A. H.

    2009-08-01

    AISI 301 and E-BRITE stainless steels were subjected to low-temperature (743 K) carburization experiments using a commercial technology developed for carburization of 316 austenitic stainless steels. The AISI 301 steel contained ~40 vol pct ferrite before carburization but had a fully austenitic hardened case, ~20- ?m thick, and a surface carbon concentration of ~8 at. pct after treatment; this colossal paraequilibrium carbon supersaturation caused an increase in lattice parameter of ~3 pct. The E-BRITE also developed a hardened case, 12- to 18- ?m thick, but underwent a more modest (~0.3 pct) increase in lattice parameter; the surface carbon concentration was ~10 at. pct. While the hardened case on the AISI 301 stainless steel appeared to be single-phase austenite, evidence for carbide formation was apparent in X-ray diffractometer (XRD) scans of the E-BRITE. Paraequilibrium phase diagrams were calculated for both AISI 301 and E-BRITE stainless steels using a CALPHAD compound energy-based interstitial solid solution model. In the low-temperature regime of interest, and based upon measured paraequilibrium carbon solubilities, more negative Cr-carbon interaction parameters for austenite than those in the current CALPHAD data base may be appropriate. A sensitivity analysis involving Cr-carbon interaction parameters for ferrite found a strong dependence of carbon solubility on relatively small changes in the magnitude of these parameters.

  16. Pitting corrosion of low-Cr austenitic stainless steels

    SciTech Connect

    Bullard, Sophie J.; Covino, Bernard S. Jr. [Dept. of Energy, Albany, OR (United States). Albany Research Center

    1996-01-01

    The Albany Research Center has investigated the pitting corrosion resistance of experimental low-Cr stainless steels and several commercial stainless steels in chloride-containing aqueous and atmospheric environments. Previous research had shown the experimental alloys to be as corrosion resistant as commercial stainless steels in chloride-free acid environments. The alloys studied were Fe-8Cr-16Ni-5.5Si-1Cu-(0-1)Mo, 304 SS, and 316 SS. These alloys were examined by immersion and electrochemical tests in 3.5 wt. pct. NaCl and 6 wt.pct.FeCl{sub 3}. Results of these tests showed that the addition of one weight percent Mo improved the pitting resistance of the low-Cr alloy and that the Mo-containing experimental alloy was as resistant to pitting as the commercial alloys. Electrochemical tests did, however, show the experimental alloys to be slightly less resistant to pitting than the commercial alloys. Because of these results, the low-Cr alloy with one weight percent Mo and 304 SS were exposed for one year to a marine atmospheric environment on the coast of Oregon. The marine atmospheric corrosion resistance of the low-Cr alloy was found to be comparable to that for type 304 stainless steel.

  17. Battery and fuel cell electrodes containing stainless steel charging additive

    DOEpatents

    Zuckerbrod, David (Pittsburgh, PA); Gibney, Ann (Monroeville, PA)

    1984-01-01

    An electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer comprises a hydrophilic composite which includes: (i) carbon particles; (ii) stainless steel particles; (iii) a nonwetting agent; and (iv) a catalyst, where at least one current collector contacts said composite.

  18. 2012 ACCOMPLISHMENTS - TRITIUM AGING STUDIES ON STAINLESS STEELS

    SciTech Connect

    Morgan, M.

    2013-01-31

    This report summarizes the research and development accomplishments during FY12 for the tritium effects on materials program. The tritium effects on materials program is designed to measure the long-term effects of tritium and its radioactive decay product, helium-3, on the structural properties of forged stainless steels which are used as the materials of construction for tritium reservoirs. The FY12 R&D accomplishments include: (1) Fabricated and Thermally-Charged 150 Forged Stainless Steel Samples with Tritium for Future Aging Studies; (2) Developed an Experimental Plan for Measuring Cracking Thresholds of Tritium-Charged-and-Aged Steels in High Pressure Hydrogen Gas; (3) Calculated Sample Tritium Contents For Laboratory Inventory Requirements and Environmental Release Estimates; (4) Published report on Cracking Thresholds and Fracture Toughness Properties of Tritium-Charged-and-Aged Stainless Steels; and, (5) Published report on The Effects of Hydrogen, Tritium, and Heat Treatment on the Deformation and Fracture Toughness Properties of Stainless Steels. These accomplishments are highlighted here and references given to additional reports for more detailed information.

  19. Bactericidal behavior of Cu-containing stainless steel surfaces

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangyu; Huang, Xiaobo; Ma, Yong; Lin, Naiming; Fan, Ailan; Tang, Bin

    2012-10-01

    Stainless steels are one of the most common materials used in health care environments. However, the lack of antibacterial advantage has limited their use in practical application. In this paper, antibacterial stainless steel surfaces with different Cu contents have been prepared by plasma surface alloying technology (PSAT). The steel surface with Cu content 90 wt.% (Cu-SS) exhibits strong bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 3 h. Although the Cu-containing surface with Cu content 2.5 wt.% (CuNi-SS) can also kill all tested bacteria, this process needs 12 h. SEM observation of the bacterial morphology and an agarose gel electrophoresis were performed to study the antibacterial mechanism of Cu-containing stainless steel surfaces against E. coli. The results indicated that Cu ions are released when the Cu-containing surfaces are in contact with bacterial and disrupt the cell membranes, killing the bacteria. The toxicity of Cu-alloyed surfaces does not cause damage to the bacterial DNA. These results provide a scientific explanation for the antimicrobial applications of Cu-containing stainless steel. The surfaces with different antibacterial abilities could be used as hygienic surfaces in healthcare-associated settings according to the diverse requirement of bactericidal activities.

  20. Thermal Processing Optimization of Injection Molded Stainless Steel Powders

    Microsoft Academic Search

    Randall M. German

    1997-01-01

    Stainless steels constitute the largest materials application group for powder injection moulding. Because of the importance of these alloys, much attention has been directed to the optimization of the thermal processing, including carbon contamination control during binder burnout and sintering. Densification in sintering has been mastered such that high final densities and competitive mechanical properties are available. Property optimization and

  1. High temperature corrosion fatigue of duplex stainless steel shaft

    Microsoft Academic Search

    H. Maury; J. Bris; A. Pacheco; J. Torres; J. Wilches

    2003-01-01

    This paper describes the result of a study on fatigue corrosion failure presented by a duplex stainless steel shaft from an agrochemical plant atomization system. The 25 mm diameter shaft was driven by a 30 kW electrical motor and was running at 14,000 rpm. The shaft presented a complete section fracture near a surface bearing. In order to determine the

  2. Corrosivity of Br ? and Cl ? on duplex stainless steel

    Microsoft Academic Search

    Katsumi Yamamoto; Keizo Hosoya

    1995-01-01

    This report discusses the basis for material selection in chemical plants, especially focusing on the design of an actual plant based on laboratory corrosion test results. Both the chemical system created when chlorine gas and bromine gas were neutralized with alkaline solution, and material economics are considered when selecting duplex stainless steel as a construction material.In addition, the corrosivity of

  3. Weld between Low Alloy Steel and 316 Stainless Steel

    Microsoft Academic Search

    Changheui Jang; Jounghoon Lee; Jong Sung Kim; Tae Eun Jin

    In several locations of the pressurized water reactors, dissimilar metal welds using Inconel welding wires are used to join the low alloy steel components to stainless steel pipes. Because of the existence of different materials and chemistry variation within welds, the mechanical properties, such as tensile and fracture properties, are expected to show spatial variation. For design and integrity assessment

  4. Laves intermetallics in stainless steel-zirconium alloys

    SciTech Connect

    Abraham, D.P.; McDeavitt, S.M.; Richardson, J.W. Jr.

    1997-05-01

    Laves intermetallics have a significant effect on properties of metal waste forms being developed at Argonne National Laboratory. These waste forms are stainless steel-zirconium alloys that will contain radioactive metal isotopes isolated from spent nuclear fuel by electrometallurgical treatment. The baseline waste form composition for stainless steel-clad fuels is stainless steel-15 wt.% zirconium (SS-15Zr). This article presents results of neutron diffraction measurements, heat-treatment studies and mechanical testing on SS-15Zr alloys. The Laves intermetallics in these alloys, labeled Zr(Fe,Cr,Ni){sub 2+x}, have both C36 and C15 crystal structures. A fraction of these intermetallics transform into (Fe,Cr,Ni){sub 23}Zr{sub 6} during high-temperature annealing; the authors have proposed a mechanism for this transformation. The SS-15Zr alloys show virtually no elongation in uniaxial tension, but exhibit good strength and ductility in compression tests. This article also presents neutron diffraction and microstructural data for a stainless steel-42 wt.% zirconium (SS-42Zr) alloy.

  5. The predictive model for machinability of 304 stainless steel

    Microsoft Academic Search

    Wen-Tung Chien; Chung-Yi Chou

    2001-01-01

    This paper presents an effort to develop a predictive model for machinability of 304 stainless steel. The artificial neural network (ANN) theory was used in this model to predict surface roughness of the workpiece, the cutting force and the tool life. It is shown that the errors of the surface roughness, the cutting force and the tool life are 4.4,

  6. Nonproportional low cycle fatigue criterion for type 304 stainless steel

    Microsoft Academic Search

    Takamoto Itoh; Masao Sakane; Masateru Ohnami; Darrell F. Socie

    1995-01-01

    This paper describes a multiaxial low cycle fatigue parameter for correlating lives under nonproportional loadings. Constant amplitude low cycle fatigue tests were carried out under 14 proportional and complex nonproportional cyclic strain paths using type 304 stainless steel hollow cylinder specimens at room temperature. In nonproportional loading tests, fatigue lives are decreased by as much as a factor of 10

  7. Diffusion bonding of titanium to 304 stainless steel

    Microsoft Academic Search

    M. Ghosh; K. Bhanumurthy; G. B Kale; J. Krishnan; S. Chatterjee

    2003-01-01

    Diffusion bonding between commercially pure titanium and an austenitic stainless steel (AISI 304) has been carried out in the temperature range of 850950 C for 2 h at uniaxial pressure of 3 MPa in vacuum. The microstructure of the diffusion zone has been analysed by optical and scanning electron microscopy (SEM). The interdiffusion of the diffusing species across the interface

  8. Corrosion resistance of friction stir welded 304 stainless steel

    Microsoft Academic Search

    Seung Hwan C. Park; Yutaka S. Sato; Hiroyuki Kokawa; Kazutaka Okamoto; Satoshi Hirano; Masahisa Inagaki

    2004-01-01

    Corrosion properties were evaluated in a friction stir welded 304 stainless steel. The degree of the sensitization was small in the heat affected zone, but the advancing side of the stir zone was corroded significantly because of the formation of the sigma phase.

  9. Tension bending ratcheting tests of 304 stainless steel

    Microsoft Academic Search

    L. D. Larson; D. P. Jones; D. G. Rapp

    1996-01-01

    This paper discusses results of an experimental program conducted to investigate the strain ratcheting behavior of 304 stainless steel under various combinations of applied membrane load and displacement controlled cyclic bending strain. Tests were performed on uniaxial specimens at temperatures of 70 F (21 C) and 550 F (288 C). Bending strain, ratchet strain and axial displacement of the specimens

  10. Reactor Material Program Fracture Toughness of Type 304 Stainless Steel

    SciTech Connect

    Awadalla, N.G.

    2001-03-28

    This report describes the experimental procedure for Type 304 Stainless Steel fracture toughness measurements and the application of results. Typical toughness values are given based on the completed test program for the Reactor Materials Program (RMP). Test specimen size effects and limitations of the applicability in the fracture mechanics methodology are outlined as well as a brief discussion on irradiation effects.

  11. Materials data handbook: Stainless steel alloy A-286

    NASA Technical Reports Server (NTRS)

    Muraca, R. F.; Whittick, J. S.

    1972-01-01

    A summary of the materials property information for stainless steel alloy A-286 is presented. The scope of the information includes physical and mechanical properties at cryogenic, ambient, and elevated temperatures. Information on material procurement, metallurgy of the alloy, corrosion, environmental effects, fabrication, and bonding is developed.

  12. Effect of Preheat Temperature on Weldability of Martensitic Stainless Steel

    Microsoft Academic Search

    Sanjeev Kumar; G. P. Chaudhari; S. K. Nath; B. Basu

    2012-01-01

    13\\/4 low carbon martensitic stainless steel is conventionally used for turbine blades in hydroelectric power plants. Due to silt erosion and cavitation, heavy damage often occurs in this material. In order to enhance the life of hydro-turbine components, repair welding is needed. Selection of proper welding parameters during repair welding is therefore essential in order to control any possible deterioration

  13. Gas Leak from Vinyl Taped Stainless Steel Dressing Jars

    SciTech Connect

    Tim Hayes

    1999-03-01

    The leak rates of nitrogen gas from stainless steel dressing jars taped with 2 inch vinyl tape were measured. These results were used to calculate hydrogen leak rates from the same jars. The calculations show that the maximum concentration of hydrogen buildup in this type of container configuration will beat least 3 orders of magnitude below the lower explosion limit for hydrogen in air.

  14. Administration Donald B. Thomason, PhD

    E-print Network

    Cui, Yan

    , PhD Director, Pharmacology Edwards Park, PhD Director, Laboratory Research & Management Leonard Lothstein, PhD Director, Nursing Science Carolyn Graff, PhD, RN Director, Pharmaceutical Sciences Duane D, Pharmaceutical Sciences, and Speech and Hearing Science. The college is located on the Health Science Center

  15. Radka Stoyanova, PhD

    Cancer.gov

    Dr. Radka Stoyanova, PhD has extensive background in developing approaches to best utilize imaging techniques in cancer research, diagnosis and treatment, as well as in developing approaches for the analysis, mining, and interpretation of "big data" generated by high-throughput approaches such as genomics, proteomics, and metabolomics. She received her Masters Degree in Mathematics from the University of Sofia, Bulgaria. Dr. Stoyanova obtained her doctoral training and PhD degree at the Imperial College London, under the mentorship of Profs.

  16. pH Meter Calibration

    NSDL National Science Digital Library

    The North Carolina Community College System BioNetwork's interactive eLearning tools (IETs) are reusable chunks of training that can be deployed in a variety of courses or training programs. IETs are designed to enhance, not replace hands-on training. Learners are able to enter a hands-on lab experience better prepared and more confident. This particular IET delves into pH Meter Calibration, where visitors practice performing a three point calibration of a pH meter using buffer solutions.

  17. Stainless steel cookware as a significant source of nickel, chromium, and iron.

    PubMed

    Kuligowski, J; Halperin, K M

    1992-08-01

    Stainless steels are widely used materials in food preparation and in home and commercial cookware. Stainless is readily attacked by organic acids, particularly at cooking temperatures; hence iron, chromium, and nickel should be released from the material into the food. Nickel is implicated in numerous health problems, notably allergic contact dermatitis. Conversely, chromium and iron are essential nutrients for which stainless could be a useful source. Home cookware was examined by atomic absorption spectroscopy: seven different stainless utensils as well as cast iron, mild steel, aluminum and enamelled steel. The materials were exposed to mildly acidic conditions at boiling temperature. Nickel was a major corrosion product from stainless steel utensils; chromium and iron were also detected. It is recommended that nickel-sensitive patients switch to a material other than stainless, and that the stainless steel cookware industry seriously consider switching to a non-nickel formulation. PMID:1514841

  18. Biomimetic PEG-catecholates for stabile antifouling coatings on metal surfaces: applications on TiO2 and stainless steel.

    PubMed

    Khalil, Faiza; Franzmann, Elisa; Ramcke, Julian; Dakischew, Olga; Lips, Katrin S; Reinhardt, Alexander; Heisig, Peter; Maison, Wolfgang

    2014-05-01

    Trimeric catecholates have been designed for the stable immobilization of effector molecules on metal surfaces. The design of these catecholates followed a biomimetic approach and was inspired by natural multivalent metal binders, such as mussel adhesion proteins (MAPs) and siderophores. Three catecholates have been conjugated to central scaffolds based on adamantyl or trisalkylmethyl core structures. The resulting triscatecholates have been immobilized on TiO2 and stainless steel. In a proof of concept study we have demonstrated the high stability of the resulting nanolayers at neutral and slightly acidic pH. Furthermore, polyethylene glycol (PEG) conjugates of our triscatecholates have been synthesized and were immobilized on TiO2 and stainless steel. The PEG coated surfaces showed excellent antifouling properties upon exposure to human blood and bacteria as demonstrated by fluorescence microscopy, ellipsometry and a bacterial assay with Staphylococcus epidermidis. In addition, our PEG-triscatecholates showed no cytotoxicity against bone-marrow stem cells on TiO2. PMID:24632391

  19. Low Temperature Surface Carburization of Stainless Steels

    SciTech Connect

    Collins, Sunniva R.; Heuer, Arthur H.; Sikka, Vinod K.

    2007-12-07

    Low-temperature colossal supersaturation (LTCSS) is a novel surface hardening method for carburization of austenitic stainless steels (SS) without the precipitation of carbides. The formation of carbides is kinetically suppressed, enabling extremely high or colossal carbon supersaturation. As a result, surface carbon concentrations in excess of 12 at. % are routinely achieved. This treatment increases the surface hardness by a factor of four to five, improving resistance to wear, corrosion, and fatigue, with significant retained ductility. LTCSS is a diffusional surface hardening process that provides a uniform and conformal hardened gradient surface with no risk of delamination or peeling. The treatment retains the austenitic phase and is completely non-magnetic. In addition, because parts are treated at low temperature, they do not distort or change dimensions. During this treatment, carbon diffusion proceeds into the metal at temperatures that constrain substitutional diffusion or mobility between the metal alloy elements. Though immobilized and unable to assemble to form carbides, chromium and similar alloying elements nonetheless draw enormous amounts of carbon into their interstitial spaces. The carbon in the interstitial spaces of the alloy crystals makes the surface harder than ever achieved before by more conventional heat treating or diffusion process. The carbon solid solution manifests a Vickers hardness often exceeding 1000 HV (equivalent to 70 HRC). This project objective was to extend the LTCSS treatment to other austenitic alloys, and to quantify improvements in fatigue, corrosion, and wear resistance. Highlights from the research include the following: Extension of the applicability of the LTCSS process to a broad range of austenitic and duplex grades of steels Demonstration of LTCSS ability for a variety of different component shapes and sizes Detailed microstructural characterization of LTCSS-treated samples of 316L and other alloys Thermodynamic modeling to explain the high degree of carbon solubility possible in austenitic grades under the LTCSS process and experimental validation of model results Corrosion testing to determine the corrosion resistance improvement possible from the LTCSS process Erosion testing to determine the erosion resistance improvement possible from the LTCSS process Wear testing to quantify the wear resistance improvement possible from the LTCSS process Fatigue testing for quantifying the extent of improvement from the LTCSS process Component treating and testing under simulated and in-line commercial operations XRD verified expanded austenite lattice, with no evidence of carbide precipitation. Carbon concentration profiles via Auger and electron dispersion spectroscopy (EDS) showed carbon levels in excess of 12 at. % in treated, type 316 SS. Scanning electron microscopy (SEM) of pulled-to-failure treated tensile specimens showed slip bands and no de-cohesion of the treated layer, verifying that the layer remains ductile. Compressive stresses in excess of 2 GPa (300 ksi) have been calculated at the surface of the case. Phase diagram (CALPHAD) (ThermoCalc) and Wagner dilute solution thermodynamic models were developed that calculate the solubility of carbon in austenite as a function of alloying content for the process time and temperature. Several commercial alloys have been modeled, and the model has been used to design experimental alloys with enhanced affinity for carbon solubility at treatment temperatures. Four experimental alloys were melted, rolled, and manufactured into test specimens, and the LTCSS treatment indicated successfully enhanced results and validated the predictions based on thermodynamic modeling. Electrochemical polarization curves show a 600 to 800 mV increase in pitting potential in treated (900-1000 mV) versus non-treated (200-300 mV) type 316 in chloride solutions. Treated 316L showed crevice-corrosion behavior similar to that of Ti-6Al-4V and Hastelloy C22. Cavitation tests showed significant increases in cavitatio

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

    SciTech Connect

    DUNCAN, J.B.

    2007-06-27

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

  1. Sashwati Roy, PhD

    Cancer.gov

    Dr. Sashwati Roy is an Associate Professor of Surgery and Director of the Laser Capture Molecular Core at The Ohio State University, Columbus, Ohio. In 1994 she received her PhD degree in Physiology and Environmental Sciences and later completed her postdoctoral training at the University of California, Berkeley. Dr.

  2. Karl Krueger, PhD

    Cancer.gov

    Dr. Karl Krueger received a PhD in biochemistry from Vanderbilt University and continued his research training at NIH as a postdoctoral fellow before joining the faculty at Georgetown University School of Medicine. His research throughout this period focused on different aspects of drug receptors and their role in the nervous system.

  3. The effect of dose rate on the response of austenitic stainless steels to neutron radiaiton

    SciTech Connect

    Allen, T. R.; Cole, J I.; Trybus, Carole L.; Porter, D. L.; Tsai, Hanchung; Garner, Francis A.; Kenik, E A.; Yoshitake, T.; Ohta, Joji

    2006-01-01

    Depending on reactor design and component location, austenitic stainless steels may experience significantly different irradiation dose rates in the same reactor. Understanding the effect of dose rate on radiation performance is important to predicting component lifetime. This study examined the effect of dose rate on swelling, grain boundary segregation, and tensile properties in austenitic stainless steels through the examination of components retrieved from the Experimental Breeder Reactor-II (EBR-II) following its shutdown. Annealed 304 stainless steel, stress-relieved 304 stainless steel, 12% cold-worked 316 stainless steel, and 20% cold-worked 316 stainless steel were irradiated over a dose range of 1-56 dpa at temperatures from 371 to 440 C and dose rates from 0.5 to 5.8 ? 10*7 dpa/s. Density and tensile properties were measured for 304 and 316 stainless steel. Changes in grain boundary composition were examined for 304 stainless steel. Swelling appears to increase at lower dose rates in both 304 and 316 stainless steel, although the effect was not always statistically significant. Grain boundary segregation also appears to increase at lower dose rate in 304 stainless steel. For the range of dose rates examined, no measurable dose rate effect on tensile properties was noted for any of the steels.

  4. Internal attachment of laser beam welded stainless steel sheathed thermocouples into stainless steel upper end caps in nuclear fuel rods for the LOFT reactor

    Microsoft Academic Search

    R. K. Welty; R. D. Reid

    1980-01-01

    The feasibility of laser welding a single 0.063 inch diameter stainless steel (304) sheathed thermocouple into a stainless steel (316) upper end cap for nuclear fuel rods was determined. A laser beam was selected because of the extremely high energy input in unit volume that can be achieved allowing local fusion of a small area irrespective of the difference in

  5. Temperature Profile and Imaging Analysis of Laser Additive Manufacturing of Stainless Steel

    NASA Astrophysics Data System (ADS)

    Islam, M.; Purtonen, T.; Piili, H.; Salminen, A.; Nyrhil, O.

    Powder bed fusion is a laser additive manufacturing (LAM) technology which is used to manufacture parts layer-wise from powdered metallic materials. The technology has advanced vastly in the recent years and current systems can be used to manufacture functional parts for e.g. aerospace industry. The performance and accuracy of the systems have improved also, but certain difficulties in the powder fusion process are reducing the final quality of the parts. One of these is commonly known as the balling phenomenon. The aim of this study was to define some of the process characteristics in powder bed fusion by performing comparative studies with two different test setups. This was done by comparing measured temperature profiles and on-line photography of the process. The material used during the research was EOS PH1 stainless steel. Both of the test systems were equipped with 200 W single mode fiber lasers. The main result of the research was that some of the process instabilities are resulting from the energy input during the process.

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

    NASA Technical Reports Server (NTRS)

    Huff, Timothy L.

    1993-01-01

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

  7. Weld microstructure development and properties of precipitation-strengthened martensitic stainless steels

    SciTech Connect

    Brooks, J.

    1994-12-31

    Precipitation-strengthened martensitic stainless steels provide excellent strength (170--220 ksi Y.S.) with high corrosion resistance. However, upon aging, a large reduction in toughness may also occur. The gas tungsten arc (GTA) cold wire feed process was used to weld half inch thick plates of PH 13-8 Mo and Custom 450 from which both tensile and Charpy specimens were machined. A fundamental understanding of the details of weld microstructural evolution was developed by liquid tin quenching GTA welds in which the solidification behavior, primary phase of solidification, microsegregation, and solid-state transformations could be followed. For both alloys studied, the as-welded yield strengths were similar to those of the unaged base material, 130 ksi. Weld properties were very similar to those of the base materials for both alloy systems. Weld strength increases significantly upon aging and achieves a maximum at intermediate aging temperatures. The increase in strength is accompanied by a large decrease in Charpy impact energy; however, the minimum in toughness occurs at aging temperatures slightly less than those resulting in peak strengths. The evolution of the weld microstructure was found to support predictions of microstructural modeling. Although a high degree of alloying partitioning occurs during solidification, a large degree of homogenization occurs upon further solidification and cooling as a result of solid-state diffusion.

  8. Gaseous hydrogen embrittlement of PH 13-8 Mo steel

    NASA Astrophysics Data System (ADS)

    Ding, Y. S.; Tsay, L. W.; Chiang, M. F.; Chen, C.

    2009-04-01

    In this study, notched tensile and fatigue crack growth tests in gaseous hydrogen were performed on PH 13-8 Mo stainless steel specimens at room temperature. These specimens were susceptible to hydrogen embrittlement (HE), but at different degrees, depending on the aging conditions or the microstructures of the alloys. In hydrogen, the accelerated fatigue crack growth rate (FCGR) usually accompanied a reduced notched tensile strength (NTS) of the specimens, i.e., the faster the FCGR the lower the NTS. It was proposed that the same fracture mechanism could be applied to these two different types of specimens, regardless of the loading conditions. Rapid fatigue crack growth and high NTS loss were found in the H800 (426 C under-aged) and H900 (482 C peak-aged) specimens. The HE susceptibility of the steel was reduced by increasing the aging temperature above 593 C, which was attributed to the increased amount of austenite in the structure. Extensive quasi-cleavage fracture was observed for the specimens that were deteriorated severely by HE.

  9. Chronic interstitial nephropathy after plasma cutting in stainless steel.

    PubMed

    Petersen, R; Mikkelsen, S; Thomsen, O F

    1994-04-01

    Chromium is nephrotoxic in experimental animals. In subjects with acute chromium intoxication acute nephritis has been reported and renal function has been affected in chromium exposed workers with a high urinary chromium concentration. Chronic kidney disease after long term occupational exposure to chromium has, however, not been reported previously. A case report is presented concerning a 48 year old man who was diagnosed with chronic interstitial nephropathy. He had worked for nine years as a plasma cutter of stainless steel and had thereby been exposed to smoke containing chromium. At the time of diagnosis his blood chromium concentration was seven times higher and his urinary chromium concentration six times higher than reference values. Taking into account the nephrotoxicity of chromium and the high chromium burden of this patient it is considered likely that his exposure to smoke from plasma cutting of stainless steel was the cause of his chronic interstitial nephropathy. PMID:8199668

  10. Fatigue Properties of DLC-Coated Stainless Steel

    NASA Astrophysics Data System (ADS)

    Morita, Tatsuro; Tomita, Kouta; Kagaya, Chuji; Kumakiri, Tadashi; Ikenaga, Masaru

    This study was conducted to investigate the effect of DLC (diamond-like carbon) coating on fatigue properties of austenitic stainless steel SUS304. For the DLC coating, UBMS (unbalanced magnetron sputtering) equipment was used. The generated surface layer of about 2 ?m thickness was composed of both the DLC layer possessing high hardness and a very thin intermediate layer to improve adhesion force between the DLC layer and the substrate. DLC coating, which was carried out at a relatively low temperature, had no influence on the microstructure so that the mechanical properties of the stainless steel were unchanged by the coating. The results of the plane-bending fatigue test showed that the DLC coating improved fatigue strength by 18%. From the results of detailed observation conducted on the fatigue fracture surface, it was suggested that the improvement in fatigue strength resulted from the suppression of fatigue crack initiation due to the surface layer, which had high adhesion force and strength.

  11. Sensitization and IGSCC susceptibility prediction in stainless steel pipe weldments

    SciTech Connect

    Atteridge, D.G.; Simmons, J.W.; Li, Ming (Oregon Graduate Inst. of Science and Technology, Beaverton, OR (United States)); Bruemmer, S.M. (Pacific Northwest Lab., Richland, WA (United States))

    1991-11-01

    An analytical model, based on prediction of chromium depletion, has been developed for predicting thermomechanical effects on austenitic stainless steel intergranular stress corrosion cracking (IGSCC) susceptibility. Model development and validation is based on sensitization development analysis of over 30 Type 316 and 304 stainless steel heats. The data base included analysis of deformation effects on resultant sensitization development. Continuous Cooling sensitization behavior is examined and modelled with and without strain. Gas tungsten are (GTA) girth pipe weldments are also characterized by experimental measurements of heat affected zone (HAZ) temperatures, strains and sensitization during/after each pass; pass by pass thermal histories are also predicted. The model is then used to assess pipe chemistry changes on IGSCC resistance.

  12. Milling and Drilling Evaluation of Stainless Steel Powder Metallurgy Alloys

    SciTech Connect

    Lazarus, L.J.

    2001-12-10

    Near-net-shape components can be made with powder metallurgy (PM) processes. Only secondary operations such as milling and drilling are required to complete these components. In the past and currently production components are made from powder metallurgy (PM) stainless steel alloys. process engineers are unfamiliar with the difference in machining properties of wrought versus PM alloys and have had to make parts to develop the machining parameters. Design engineers are not generally aware that some PM alloy variations can be furnished with machining additives that greatly increase tool life. Specimens from a MANTEC PM alloy property study were made available. This study was undertaken to determine the machining properties of a number of stainless steel wrought and PM alloys under the same conditions so that comparisons of their machining properties could be made and relative tool life determined.

  13. STAINLESS STEEL INTERACTIONS WITH SALT CONTAINING PLUTONIUM OXIDES

    SciTech Connect

    Nelson, Z.; Chandler, G.; Dunn, K.; Stefek, T.; Summer, M.

    2010-02-01

    Salt containing plutonium oxide materials are treated, packaged and stored within nested, stainless steel containers based on requirements established in the DOE 3013 Standard. The moisture limit for the stored materials is less than 0.5 weight %. Surveillance activities which are conducted to assess the condition of the containers and assure continuing 3013 container integrity include the destructive examination of a select number of containers to determine whether corrosion attack has occurred as a result of stainless steel interactions with salt containing plutonium oxides. To date, some corrosion has been observed on the innermost containers, however, no corrosion has been noted on the outer containers and the integrity of the 3013 container systems is not expected to be compromised over a 50 year storage lifetime.

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

    SciTech Connect

    Zaleski, T M

    2008-10-23

    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.

  15. Electrochemical Corrosion Testing of Borated Stainless Steel Alloys

    SciTech Connect

    lister, tedd e; Mizia, Ronald E

    2007-05-01

    The Department of Energy Office of Civilian Radioactive Waste Management has specified borated stainless steel manufactured to the requirements of ASTM A 887-89, Grade A, UNS S30464, to be the material used for the fabrication of the fuel basket internals of the preliminary transportation, aging, and disposal canister system preliminary design. The long-term corrosion resistance performance of this class of borated materials must be verified when exposed to expected YMP repository conditions after a waste package breach. Electrochemical corrosion tests were performed on crevice corrosion coupons of Type 304 B4 and Type 304 B5 borated stainless steels exposed to single postulated in-package chemistry at 60C. The results show low corrosion rates for the test period

  16. Long-Term Underground Corrosion of Stainless Steels

    SciTech Connect

    M. K. Adler Flitton; T. S. Yoder

    2007-03-01

    In 1970, the National Institute of Standards and Technology (NIST) implemented the most ambitious and comprehensive long-term corrosion behavior test to date for stainless steels in soil environments. Over thirty years later, one of the six test sites was targeted to research subsurface contamination and transport processes in the vadose and saturated zones. This research directly applies to environmental management operational corrosion issues and long term stewardship scientific needs for understanding the behavior of waste forms and their near-field contaminant transport of chemical and radiological contaminants at nuclear disposal sites. This paper briefly describes the ongoing research and the corrosion analysis results of the stainless steel plate specimens recovered from the partial recovery of the first test site.

  17. Electrochemical Corrosion Testing of Borated Stainless Steel Alloys

    SciTech Connect

    lister, tedd e; Mizia, Ronald E

    2007-09-01

    The Department of Energy Office of Civilian Radioactive Waste Management has specified borated stainless steel manufactured to the requirements of ASTM A 887-89, Grade A, UNS S30464, to be the material used for the fabrication of the fuel basket internals of the preliminary transportation, aging, and disposal canister system preliminary design. The long-term corrosion resistance performance of this class of borated materials must be verified when exposed to expected YMP repository conditions after a waste package breach. Electrochemical corrosion tests were performed on crevice corrosion coupons of Type 304 B4 and Type 304 B5 borated stainless steels exposed to single postulated in-package chemistry at 60C. The results show low corrosion rates for the test period

  18. Dissimilar metal crevice corrosion of highly alloyed stainless steel

    SciTech Connect

    Salamat, G.; Kelly, R.G. [Univ. of Virginia, Charlottesville, VA (United States)

    1994-12-31

    Highly alloyed stainless steels can suffer from dissimilar metal crevice corrosion when creviced with certain other stainless alloys. In order to understand this phenomenon better, the solution which forms inside such crevices was collected and analyzed with ion chromatography and capillary electrophoresis for its metal ion content. These analyses provided the data required to design bulk solutions for electrochemical measurements. Electrochemical measurements in these simulated crevice solutions were made and compared to measurements made in simple acidified chloride solutions. The simulated crevice solutions were found to be much more aggressive. These results are used to rationalize the observations of dissimilar metal crevice corrosion of Alloy S44735 when it is creviced with Type 316 and the failure of electrochemical measurements in simple acidified chloride solutions to predict this attack. The roles of ohmic drop and chloride ion concentration are considered.

  19. 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.

  20. Stella Koutros, Ph.D.

    Cancer.gov

    Dr. Koutros received her M.P.H. and Ph.D. in epidemiology from Yale University. She completed her doctoral work through the Yale-NCI partnership training program in cancer epidemiology, conducting research in the Occupational and Environmental Epidemiology Branch (OEEB). In 2008, upon completion of her doctorate she became a fellow in OEEB; she was appointed to the position of tenure-track investigator in 2015.

  1. Christos Patriotis, PhD

    Cancer.gov

    Dr. Christos Patriotis obtained his MSc in Biochemistry from the University of Sofia, Bulgaria in 1985 and his PhD in Molecular Biology from the Bulgarian Academy of Sciences in 1990. Postdoctoral training focused on signal transduction and tumor cell biology. He joined the faculty at Fox Chase Cancer Center in 1998; his research was directed toward understanding mechanisms of breast and ovarian cancer pathogenesis and identification of biomarkers associated with the early stages of the two types of cancer.

  2. Richard Mazurchuk, PhD

    Cancer.gov

    Dr. Richard Mazurchuk received a BS in Physics and MS and PhD in Biophysics from SUNY Buffalo. His research focused on developing novel multi-modality imaging techniques, contrast (enhancing) agents and methods to assess the efficacy of experimental therapeutics. He subsequently joined the faculty of SUNY Buffalo School of Medicine and Roswell Park Cancer Institute attaining the rank of Assoc Prof in the Departments of Diagnostic Imaging and Molecular and Cellular Biochemistry and Biophysics.

  3. PhET: The Ramp

    NSDL National Science Digital Library

    In this simulation, students push common items of varying masses up an incline to explore the relationship of applied force, work, and energy. They control the angle of the ramp, friction, and amount of applied force. With a mouse click, they can also view detailed graphs of work and energy. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments.

  4. The pH of antiseptic cleansers

    PubMed Central

    Kulthanan, Kanokvalai; Varothai, Supenya; Nuchkull, Piyavadee

    2014-01-01

    Background Daily bathing with antiseptic cleansers are proposed by some physicians as an adjunctive management of atopic dermatitis (AD). As atopic skin is sensitive, selection of cleansing products becomes a topic of concern. Objective Our purpose is to evaluate the pH of various antiseptic body cleansers to give an overview for recommendation to patients with AD. Methods Commonly bar and liquid cleansers consisted of antiseptic agents were measured for pH using pH meter and pH-indicator strips. For comparison, mild cleansers and general body cleansers were also measured. Results All cleansing bars had pH 9.8-11.3 except syndet bar that had neutral pH. For liquid cleansers, three cleansing agents had pH close to pH of normal skin, one of antiseptic cleansers, one of mild cleansers and another one of general cleansers. The rest of antiseptic cleansers had pH 8.9-9.6 while mild cleansers had pH 6.9-7.5. Syndet liquid had pH 7 and general liquid cleansers had pH 9.6. Conclusion The pH of cleanser depends on composition of that cleanser. Adding antiseptic agents are not the only factor determining variation of pH. Moreover, benefit of antiseptic properties should be considered especially in cases of infected skin lesions in the selection of proper cleansers for patients with AD. PMID:24527408

  5. Nitriding of austenitic stainless steel by plasma immersion ion implantation

    Microsoft Academic Search

    G. A. Collins; R. Hutchings; K. T. Short; J. Tendys; X. Li; M. Samandi

    1995-01-01

    Plasma immersion ion implantation (PI3), in which the diffusion of nitrogen from a low pressure r.f. plasma is combined with the implantation of nitrogen ions at energies up to 45 kV, is an effective means of nitriding austenitic stainless steel. At temperatures up to 450 C, tribological properties can be improved without loss of corrosion resistance. In common with other

  6. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    NASA Technical Reports Server (NTRS)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  7. Tritium Effects on Fracture Toughness of Stainless Steel Weldments

    Microsoft Academic Search

    MICHAEL MORGAN; G. K. CHAPMAN; M. H. TOSTEN; S. L. WEST

    2005-01-01

    The effects of tritium on the fracture toughness properties of Type 304L and Type 21-6-9 stainless steel weldments were measured. Weldments were tritium-charged-and-aged and then tested in order to measure the effect of the increasing decay helium content on toughness. The results were compared to uncharged and hydrogen-charged samples. For unexposed weldments having 8-12 volume percent retained delta ferrite, fracture

  8. Characterization of long term aged martensitic stainless steels

    SciTech Connect

    Tsubota, M.; Hattori, K.; Okada, T. [Toshiba Corp., Yokohama (Japan)

    1992-12-31

    Types CA6NM (13Cr), 431 and 630 (17Cr) were aged at 400{degrees}C and 350{degrees}C for up to 10000 hours, and their hardness change and SCC susceptibility in 288{degrees}C water were investigated. Hardness of the alloys increased with aging. Hardness of type 431 aged at 400{degrees}C for 10000 hours exceeded 340 in Hv, over which tempered martensitic stainless steels had become susceptible to SCC, and showed high SCC susceptibility. Type 630 had high SCC susceptibility in before and after aged condition, and the hardness in both conditions was more than Hv 340. Therefore, hardness was considered to be a parameter which could describe the SCC susceptibility of martensitic stainless steels. Using activation energy for hardness change 105-125kJ/mol and the critical hardness level Hv=340, the marginal life-time for martensitic stainless steels at 288{degrees}C was estimated. Predicted life of type 431 and CA6NM were around 10{sup 5} hours and more than 10{sup 6} hours, respectively. Activation energies obtained for toughness change and hardness change were different. Consequently, it was concluded that at least two factors should be taken into consideration for determining the total life-limit for usage of martensitic stainless steels in the light water reactor environment. The meaning of the existence of critical hardness for SCC susceptibility has been also discussed. Higher than 340 in Hv, yield strength and strain for uniform deformation showed a tendency of saturation. Therefore, it was conjectured that some extreme internal strain level, which may change the plastic deformation manner, is the absolute factor for determining the SCC susceptibility of the alloys in high temperature water.

  9. Hydrogen-assisted cracking of sensitized 316L stainless steel

    Microsoft Academic Search

    E. Minkovitz; D. Eliezer

    1981-01-01

    Thin tensile specimens of 316L-type austenitic stainless steel were tested either at room temperature after cathodic charging or whilst undergoing cathodic charging. Throughout this study we have compared solution-annealed samples with samples given the additional sensitization treatment. The results of the tensile tests show that the room temperature yield and ultimate strengths were not much affected by sensitization, whilst significant

  10. Hydrogen assisted cracking of type 304 stainless steel

    Microsoft Academic Search

    C. L. Briant

    1979-01-01

    This paper reports a study of hydrogen assisted cracking in type 304 stainless steel. It shows that the most detrimental effect\\u000a in increasing the susceptibility of the material to hydrogen cracking is the formation of martensite upon deformation. This\\u000a is particularly damaging if the martensite is localized at the grain boundaries. With martensite present intergranular impurities\\u000a such as phosphorus play

  11. Manganese-stabilized austenitic stainless steels for fusion applications

    DOEpatents

    Klueh, Ronald L. (Knoxville, TN); Maziasz, Philip J. (Oak Ridge, TN)

    1990-01-01

    An austenitic stainless steel that is comprised of Fe, Cr, Mn, C but no Ni or Nb and minimum N. To enhance strength and fabricability minor alloying additions of Ti, W, V, B and P are made. The resulting alloy is one that can be used in fusion reactor environments because the half-lives of the elements are sufficiently short to allow for handling and disposal.

  12. Hydrogen embrittlement of weld metal of austenitic stainless steels

    Microsoft Academic Search

    C. Pan; Y. J. Su; W. Y. Chu; Z. B. Li; D. T. Liang; L. J. Qiao

    2002-01-01

    Using slow strain rate tests, the role of atomic hydrogen and hydrogen-induced martensites in hydrogen embrittlement of weld metals of type 308 and type 347L austenitic stainless steel (ASS) and type 304L plate was quantitatively studied. The results indicated that hydrogen-induced martensites formed in the three kinds of ASS when diffusible hydrogen concentration C0 exceeded 30 wppm, and the total

  13. The ennoblement of stainless steel by manganic oxide biofouling

    Microsoft Academic Search

    W. H. Dickinson; F. Caccavo; Z. Lewandowski

    1996-01-01

    Twenty-three 316L stainless steel (SS) coupons were exposed in situ to fresh river-water for periods of up to 35 days. All samples developed steady-state corrosion potentials (Ecorr) near + 350 mV (SCE) and polarization measurements showed enhanced cathodic current density characteristic of passive metal ennoblement. Epifluorescence and scanning electron microscopy of the attached biofilm showed numerous 1020?m diameter Mn-rich annular

  14. On the stress corrosion cracking mechanisms of austenitic stainless steels

    Microsoft Academic Search

    P Rodriguez; H S Khatak; J B Gnanamoorthy

    1994-01-01

    In this paper, experimental results on stress corrosion cracking in austenitic stainless steels are described. Crack growth\\u000a data in sodium chloride solution for AISI 304 steel obtained for different metallurgical conditions, acoustic emission data\\u000a recorded during crack growth and fractographic observations have been discussed with a view to identifying the operating mechanism.\\u000a Some of the experimental observations such as crack

  15. Oxidation of stainless steel 304L in carbon dioxide

    Microsoft Academic Search

    F. Goutier; S. Valette; A. Vardelle; P. Lefort

    2010-01-01

    Oxidation of 304L stainless steel in a carbon dioxide atmosphere at 105 Pa has been studied. Between 1193 and 1293K the oxidation kinetics exhibit first a rapid increase, then a parabolic behaviour with apparent activation energy of (2098) kJmol?1 and obeys a Langmuir pressure law. After 1.15mgcm?2, the kinetics become almost linear.The reaction products are chromia at the grain boundaries,

  16. TEM characterization of a nitrogen implanted austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Fayeulle, S.; Treheux, D.; Esnouf, C.

    1986-04-01

    Pure austenitic stainless-steel samples (18% Cr, 10% Ni) were implanted at room temperature with nitrogen ions at an energy of 40 keV with fluences from 10 17 to 6X10 17 ions cm -2. Microstructures obtained after implantation were studied by transmission electron microscopy and selected-area diffraction. The observations show the formation of ? martensite (hexagonal), of ?' martensite (tetragonal) and the appearance of nitrides (Fe, Cr, Ni) 2N 1- x hexagonal or orthorhombic.

  17. Laser surface modification of stainless steels for cavitation erosion resistance

    Microsoft Academic Search

    Chi Tat Kwok

    1999-01-01

    Austenitic stainless steel UNS S31603 (Fe -17.6Cr -11.2Ni -2.5Mo -1.4Mn -0.4Si -0.03C) has higher pitting corrosion resistance but lower cavitation erosion resistance than that of UNS S30400. This is because of its lower tendency for strain induced martensitic transformation and higher stacking fault energy as compared with those of UNS S30400. In order to improve its cavitation erosion resistance, surface

  18. Origin of Interference Colors on Austenitic Stainless Steel

    Microsoft Academic Search

    L. D. Vazquez-Santoyo; J. J. Perez-Bueno; A. Manzano-Ramirez; J. Gonzalez-Hernandez; J. F. Perez-Robles; Yu. V. Vorobiev

    2005-01-01

    Data are presented on the coloring conditions, colored layer parameters, and color characteristics of stainless steel 304 samples treated in an electrolytic cell (60 Hz, 100 mV) using a mixture of 5 M sulfuric acid and 2.5 M chromic acid. Reflectance spectra indicate that the samples have high-purity color mainly in the yellow region and that the color is due

  19. Method of polishing nickel-base alloys and stainless steels

    DOEpatents

    Steeves, Arthur F. (Schenectady, NY); Buono, Donald P. (Schenectady, NY)

    1981-01-01

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels. The chemical attack polish comprises Fe(NO.sub.3).sub.3, concentrated CH.sub.3 COOH, concentrated H.sub.2 SO.sub.4 and H.sub.2 O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  20. Attack polish for nickel-base alloys and stainless steels

    DOEpatents

    Steeves, Arthur F. (Schenectady, NY); Buono, Donald P. (Schenectady, NY)

    1983-01-01

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels. The chemical attack polish comprises Fe(NO.sub.3).sub.3, concentrated CH.sub.3 COOH, concentrated H.sub.2 SO.sub.4 and H.sub.2 O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  1. Deflagration in stainless steel storage containers containing plutonium dioxide

    SciTech Connect

    Kleinschmidt, P.D.

    1996-02-01

    Detonation of hydrogen and oxygen in stainless steel storage containers produces maximum pressures of 68.5 psia and 426.7 psia. The cylinders contain 3,000 g of PuO{sub 2} with 0.05 wt% and 0.5 wt% water respectively. The hydrogen and oxygen are produced by the alpha decomposition of the water. Work was performed for the Savannah River Site.

  2. The applicability of duplex stainless steels in sour environments

    Microsoft Academic Search

    H. Eriksson; S. Bernhardsson

    1991-01-01

    Very low tolerable partial pressures of HS(p{sub Hs}) have been reported for duplex stainless steels in sour environments. However, such steels resist stress corrosion cracking (SCC) in sour environments even at substantial P{sub HS} values. This paper reports that, to assess the limits of applicability, SCC tests should include an environmental of reasonably accelerated severity. It is also important to

  3. Structure and properties of plasma-nitrided stainless steel

    Microsoft Academic Search

    E. Menthe; K.-T. Rie; J. W. Schultze; S. Simson

    1995-01-01

    A series of plasma-nitriding experiments has been conducted on AISI 304L austenitic stainless steel at temperatures ranging from 400 to 600 C using a pulsed d.c. plasma with various pulse duration\\/repetition ratios in an N2?H2 gas mixture. The structure and composition of the plasma-nitrided surface layer were analysed by means of X-ray diffraction (XRD), scanning electron microscopy, X-ray photoelectron spectroscopy

  4. Magnetic properties of Cr-Mn austenitic stainless steels

    Microsoft Academic Search

    Maria Fldeki; Hassel Ledbetter; Peter Uggowitzer

    1992-01-01

    The magnetic susceptibility x of three Cr-Mn austenitic stainless steels was measured as a function of temperature in the range 5-400 K. All specimens showed a characteristic susceptibility maximum. The temperature of the maximum and especially the curve shape depend strongly on specimen composition and metallurgical conditions (as-quenched, deformed). Because no significant field dependence appeared, the susceptibility maximum was identified

  5. Initiation of corrosion pits at inclusions on 304 stainless steel

    Microsoft Academic Search

    Ruoru Ke; R. Alkire

    1995-01-01

    Onset of pitting corrosion on 304 stainless steel in 0.1 M NaCl was investigated at the site of approximately 200 inclusions. A photolithography technique was used to locate individual sites repeatedly in order to characterize them by a combination of scanning electron microscopy, energy dispersive X-ray, and Auger electron spectroscopy methods. Growth of pits to significant size was found to

  6. Dynamic recrystallization behavior of AISI 304 stainless steel

    Microsoft Academic Search

    Sung-Il Kim; Yeon-Chul Yoo

    2001-01-01

    The dynamic recrystallization (DRX) of AISI 304 stainless steel was studied with torsion test in the temperature range of 9001100C and the strain rate range of 5.010?25.0100 s?1. The initiation and evolution of DRX were investigated with microstructural analysis and then the critical strain for DRX initiation could be confirmed by analysis of flow stress. The volume fraction of DRX

  7. In-reactor deformation and fracture of austenitic stainless steels

    Microsoft Academic Search

    E. E. Bloom; W. G. Wolfer

    1978-01-01

    An experimental technique for determining in-reactor fracture strain was developed and demonstrated. Differential swelling between a sample holder and a test specimen with a lower swelling rate produced uniaxial deformation. In-reactor deformations of 0.7 to 2.1% were achieved in type 304 stainless steel previously irradiated to fluences up to 8.8 x 10²⁶ n\\/m² without fracture. These strains are significantly higher

  8. Analysis of elevated temperature cyclic deformation of austenitic stainless steels

    Microsoft Academic Search

    R. W. Rohde; J. C. Swearengen

    1977-01-01

    The stress relaxation behavior of 304 and 316 stainless steels during cyclic deformation at 538 and 650°C with various hold times and strain amplitudes has been analyzed in terms of a power-law equation of state which includes internal stress and drag stress as structure variables. At 650°C the internal sress in 304 appears to be zero and microstructural recovery plays

  9. Attack polish for nickel-base alloys and stainless steels

    DOEpatents

    Not Available

    1980-05-28

    A chemical attack polish and polishing procedure for use on metal surfaces such as nickel base alloys and stainless steels is described. The chemical attack polich comprises FeNO/sub 3/, concentrated CH/sub 3/COOH, concentrated H/sub 2/SO/sub 4/ and H/sub 2/O. The polishing procedure includes saturating a polishing cloth with the chemical attack polish and submicron abrasive particles and buffing the metal surface.

  10. Titanium and molybdenum content in supermartensitic stainless steel

    Microsoft Academic Search

    C. A. D. Rodrigues; P. L. D. Lorenzo; A. Sokolowski; C. A. Barbosa; J. M. D. A. Rollo

    2007-01-01

    The supermartensitic stainless steels (SMSS) must be developed considering a balance between strength and toughness that are achieved by controlling the chemical compositions and heat treatment. In this paper, the results of detailed investigations on 12.50 Cr5.40 Ni2.10 Mo0.13 Ti SMSS composition were obtained after the SMSS was put in a vacuum furnace and subsequently hot rolled and heat-treated. A

  11. The reversion of martensite to austenite in certain stainless steels

    Microsoft Academic Search

    H. Smith; D. R. F. West

    1973-01-01

    An investigation has been made of the reversion of martensite (a') to austenite (?) in two stainless steels (i) Fe-16 wt% Cr-12 wt% Ni (of low interstitial content) (ii) Fe-15 wt% Cr-8 1\\/2 wt% Ni-2 wt% Mo-0.09 wt% C. The alloys were refrigerated to produce ~ 12 to 15% martensite (a') and then heated for short times at various temperatures

  12. 37. REDUCTION PLANT DRYER Stainless steel screen cylinder, encased ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. REDUCTION PLANT - DRYER Stainless steel screen cylinder, encased within an outer steel shell (top half missing). As fish were tumbled by the rotating screen, they were cooked and dried by live steam piped into the dryer through overhead pipes. The dryer is mounted on a slight angle, aiding the process by moving the drying fish towards the exhaust end of the dryer. - Hovden Cannery, 886 Cannery Row, Monterey, Monterey County, CA

  13. Recombination coefficients of O and N radicals on stainless steel

    NASA Astrophysics Data System (ADS)

    Singh, Harmeet; Coburn, J. W.; Graves, David B.

    2000-09-01

    Surface recombination coefficients of O and N radicals in pure O2 and N2 plasmas, respectively, have been estimated on the stainless steel walls of a low-pressure inductively coupled plasma reactor. The recombination coefficients are estimated using a steady state plasma model describing the balance between the volume generation of the radicals from electron-impact dissociation of the parent molecules, and the loss of the radicals due to surface recombination. The model uses radical and parent molecule number densities and the electron energy distribution function (EEDF) as input parameters. We have measured the radical number density using appearance potential mass spectrometry. The parent neutral number density is measured using mass spectrometry. The EEDF is measured using a Langmuir probe. The recombination coefficient of O radicals on stainless steel walls at approximately 330 K is estimated to be 0.170.02, and agrees well with previous measurements. The recombination coefficient of N radicals is estimated to be 0.070.02 on stainless steel at 330 K.

  14. Reducing tool wear when machining austenitic stainless steels

    SciTech Connect

    Magee, J.H.; Kosa, T.

    1998-07-01

    Austenitic stainless steels are considered more difficult to machine than carbon steels due to their high work hardening rate, large spread between yield and ultimate tensile strength, high toughness and ductility, and low thermal conductivity. These characteristics can result in a built-up edge or excessive tool wear during machining, especially when the cutting speed is too high. The practical solution is to lower the cutting speed until tool life reaches an acceptable level. However, lower machining speed negatively impacts productivity. Thus, in order to overcome tool wear at relatively high machining speeds for these alloys, on-going research is being performed to improve cutting fluids, develop more wear-resistant tools, and to modify stainless steels to make them less likely to cause tool wear. This paper discusses compositional modifications to the two most commonly machined austenitic stainless steels (Type 303 and 304) which reduced their susceptibility to tool wear, and allowed these grades to be machined at higher cutting speeds.

  15. Characterization of blasted austenitic stainless steel and its corrosion resistance

    NASA Astrophysics Data System (ADS)

    Otsubo, F.; Kishitake, K.; Akiyama, T.; Terasaki, T.

    2003-12-01

    It is known that the corrosion resistance of stainless steel is deteriorated by blasting, but the reason for this deterioration is not clear. A blasted austenitic stainless steel plate (JIS-SUS304) has been characterized with comparison to the scraped and non-blasted specimens. The surface roughness of the blasted specimen is larger than that of materials finished with #180 paper. A martensite phase is formed in the surface layer of both blasted and scraped specimens. Compressive residual stress is generated in the blasted specimen and the maximum residual stress is formed at 50 100 m from the surface. The corrosion potentials of the blasted specimen and subsequently solution treated specimen are lower than that of the non-blasted specimen. The passivation current densities of the blasted specimens are higher those of the non-blasted specimen. The blasted specimen and the subsequently solution treated specimen exhibit rust in 5% sodium chloride (NaCl) solution, while the non-blasted specimen and ground specimen do not rust in the solution. It is concluded that the deterioration of corrosion resistance of austenitic stainless steel through blasting is caused by the roughed morphology of the surface.

  16. Characterisation of passive films on 300 series stainless steels

    NASA Astrophysics Data System (ADS)

    Wijesinghe, T. L. Sudesh L.; Blackwood, D. J.

    2006-11-01

    The formation and breakdown of the passive films on stainless steels are mainly controlled by ionic and electronic transport processes. Both these processes are in part controlled by the electronic properties of the oxide film. Consequently, it is vital to gain a detailed perception of the electronic properties of the passive films together with structural and compositional information for a comprehensive understanding of mechanisms behind passivity and localised corrosion. As a step towards this goal the passive films formed on two main austenitic stainless steels AISI 316L and AISI 304L in borate solution were characterised by in situ Raman spectroscopy and photocurrent spectroscopy coupled with electrochemical measurements. This revealed the formation of an Fe-Cr spinel as the dominant constituent in the passive films with more Cr enrichment in the oxide film on 316L than that of 304L. Bandgap readings and semiconductivities of the two stainless steels suggested that three different applied potential regions existed; 800 mV(SCE) to 300 mV(SCE), 200 mV(SCE) to -300 mV(SCE) and below -500 mV(SCE).

  17. Surface interactions of cesium and boric acid with stainless steel

    SciTech Connect

    Grossman-Canfield, N.

    1995-08-01

    In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction.

  18. Iodine susceptibility of pseudomonads grown attached to stainless steel surfaces

    NASA Technical Reports Server (NTRS)

    Pyle, B. H.; McFeters, G. A.

    1990-01-01

    Pseudomonads were adapted to grow in phosphate-buffered water and on stainless steel surfaces to study the iodine sensitivity of attached and planktonic cells. Cultures adapted to low nutrient growth were incubated at room temperature in a circulating reactor system with stainless steel coupons to allow biofilm formation on the metal surfaces. In some experiments, the reactor was partially emptied and refilled with buffer at each sampling time to simulate a "fill-and-draw" water system. Biofilms of attached bacteria, resuspended biofilm bacteria, and reactor suspension, were exposed to 1 mg l-1 iodine for 2 min. Attached bacterial populations which established on coupons within 3 to 5 days displayed a significant increase in resistance to iodine. Increased resistance was also observed for resuspended cells from the biofilm and planktonic bacteria in the system suspension. Generally, intact biofilms and resuspended biofilm cells were most resistant, followed by planktonic bacteria and phosphate buffer cultures. Thus, biofilm formation on stainless steel surfaces within water systems can result in significantly increased disinfection resistance of commonly-occurring water-borne bacteria that may enhance their ability to colonise water treatment and distribution systems.

  19. Magnetic properties of stainless steels at room and cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Oxley, Paul; Goodell, Jennifer; Molt, Robert

    2009-07-01

    The magnetic properties of ten types of ferritic and martensitic stainless steels have been measured at room temperature and at 77 K. The steel samples studied were in the annealed state as received from the manufacturer. Our room temperature measurements indicate significantly harder magnetic properties than those quoted in the ASM International Handbook, which studied fully annealed stainless steel samples. Despite having harder magnetic properties than fully annealed steels some of the as-received steels still display soft magnetic properties adequate for magnetic applications. The carbon content of the steels was found to affect the permeability and coercive force, with lower-carbon steels displaying significantly higher permeability and lower coercive force. The decrease in coercive force with reduced carbon content is attributed to fewer carbide inclusions which inhibit domain wall motion. Cooling to 77 K resulted in harder magnetic properties. Averaged over the ten steels tested the maximum permeability decreased by 8%, the coercive force increased by 14%, and the residual and saturation flux densities increased by 4% and 3%, respectively. The change in coercive force when cooled is comparable to the theoretical prediction for iron, based on a model of domain wall motion inhibited by inclusions. The modest changes of the magnetic properties indicate that the stainless steels can still be used in magnetic applications at very low temperatures.

  20. Corrosion Performance of Stainless Steels in a Simulated Launch Environment

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Vinje, Rubiela D.; MacDowell, Louis

    2004-01-01

    At the Kennedy Space Center, NASA relies on stainless steel (SS) tubing to supply the gases and fluids required to launch the Space Shuttle. 300 series SS tubing has been used for decades but the highly corrosive environment at the launch pad has proven to be detrimental to these alloys. An upgrade with higher alloy content materials has become necessary in order to provide a safer and long lasting launch facility. In the effort to find the most suitable material to replace the existing AISI 304L SS ([iNS S30403) and AISI 316L SS (UNS S31603) shuttle tubing, a study involving atmospheric exposure at the corrosion test site near the launch pads and electrochemical measurements is being conducted. This paper presents the results of an investigation in which stainless steels of the 300 series, 304L, 316L, and AISI 317L SS (UNS S31703) as well as highly alloyed stainless steels 254-SMO (UNS S32154), AL-6XN (N08367) and AL29-4C ([iNS S44735) were evaluated using direct current (DC) electrochemical techniques under conditions designed to simulate those found at the Space Shuttle Launch pad. The electrochemical results were compared to the atmospheric exposure data and evaluated for their ability to predict the long-term corrosion performance of the alloys.