scholarly journals Development of Nanocrystalline 304L Stainless Steel by Large Strain Cold Working

Metals ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 656-668 ◽  
Author(s):  
Marina Odnobokova ◽  
Andrey Belyakov ◽  
Rustam Kaibyshev
Keyword(s):  
Stainless Steel ◽  
Cold Working ◽  
Large Strain ◽  
304L Stainless Steel

The Effect of Stress-State on the Large Strain Inelastic Deformation Behavior of 304L Stainless Steel

1996 ◽  
Vol 118 (1) ◽  
pp. 28-36 ◽  
Author(s):  
M. P. Miller ◽  
D. L. McDowell
Keyword(s):  
Stainless Steel ◽  
Stress State ◽  
Strain Hardening ◽  
Crystallographic Texture ◽  
Inelastic Deformation ◽  
Large Strain ◽  
Relative Effect ◽  
Material Behavior ◽  
304L Stainless Steel ◽  
Inelastic Material

In metals, large strain inelastic deformation processes such as the formation of a preferred crystallographic orientation (crystallographic texture) and strain hardening processes such as the formation and evolution of dislocation substructures depend on stress-state. Much of the current large strain research has focused on texture. Crystallographic texture development and strainhardening processes each contribute to the overall material behavior, and a complete description of large strain inelastic material response should reflect both. An investigation of the large strain behavior of 304L stainless steel (SS 304L) subjected to compression, torsion, and sequences of compression followed by torsion and torsion followed by tension is reported. This paper focuses on the stress-state dependence of strain-hardening processes as well as the relative effect such processes have on the overall material behavior. To characterize these processes, transmission electron microscopy (TEM) as well as magnetization investigations were conducted at different strain levels and under different deformation modes. The γ → α′ martensitic transformation which occurs in this material was found to be related to both the strain level and stress state. Dislocation substructures in the form of Taylor lattices, dense dislocation walls, and microbands were also present. The ramifications of using a thin-walled tubular torsion specimen were also explored.

scholarly journals On Strengthening of Austenitic Stainless Steel by Large Strain Cold Working

2016 ◽  
Vol 56 (7) ◽  
pp. 1289-1296 ◽  
Author(s):  
Iaroslava Shakhova ◽  
Andrey Belyakov ◽  
Zhanna Yanushkevich ◽  
Kaneaki Tsuzaki ◽  
Rustam Kaibyshev
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Working ◽  
Large Strain

Annealing behavior of a 304L stainless steel processed by large strain cold and warm rolling

2017 ◽  
Vol 689 ◽  
pp. 370-383 ◽  
Author(s):  
Marina Odnobokova ◽  
Andrey Belyakov ◽  
Nariman Enikeev ◽  
Dmitri A. Molodov ◽  
Rustam Kaibyshev
Keyword(s):  
Stainless Steel ◽  
Large Strain ◽  
Warm Rolling ◽  
304L Stainless Steel ◽  
Annealing Behavior

Deformation Microstructures in a Two-Phase Stainless Steel during Large Strain Deformation

2006 ◽  
Vol 503-504 ◽  
pp. 305-310
Author(s):  
Kaneaki Tsuzaki ◽  
Andrey Belyakov ◽  
Yuuji Kimura
Keyword(s):  
Stainless Steel ◽  
Cold Working ◽  
Large Strain ◽  
Deformation Behaviour ◽  
Large Strains ◽  
Transverse Size ◽  
Plastic Working ◽  
Two Phase ◽  
Two Phases ◽  
Kinetics Of

Deformation microstructures were studied in a two-phase (about 60% ferrite and 40% austenite) Fe – 27%Cr – 9%Ni stainless steel. Severe plastic working was carried out by rolling from 21.3×21.3 mm2 to 7.8×7.8 mm2 square bar followed by swaging from Ø7.0 to 0.6 mm rod at an ambient temperature, providing a total strain of 6.9. After a rapid increase in the hardness at an early deformation, the rate of the strain hardening gradually decreased to almost zero at large strains above 4. In other words, the hardness approached a saturation level, leading to an apparent steadystate deformation behaviour during cold working. The severe deformation resulted in the evolution of highly elongated (sub)grains aligned along the rolling/swaging axis with the final transverse (sub)grain size of about 0.1 μm and the fraction of high-angle (sub)boundaries above 60%. However, the kinetics of microstructure evolution in the two phases was different. In the ferrite phase, the transverse size of deformation (sub)grains gradually decreased during the processing and approached 0.1 μm at strains of about 6.0, while the transverse size of the austenite (sub)grains rapidly reduced to its final value of 0.1 μm after a relatively low strain about 1.0.

Hydrogen-Induced Phase Transformations in Type 304L Stainless Steels

CORROSION ◽  
1968 ◽  
Vol 24 (4) ◽  
pp. 110-124 ◽  
Author(s):  
M. L. HOLZWORTH ◽  
M. R. LOUTHAN
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Low Temperatures ◽  
Room Temperature ◽  
Cold Working ◽  
Stacking Fault ◽  
304L Stainless Steel ◽  
Fault Density ◽  
Ε Phase ◽  
Dislocation Movement

Abstract Electrolytic charging of hydrogen into Type 304L stainless steel at room temperature and 100 C (212 F) induced partial transformation) of the austenite to the some martensitic phases [α′ (bcc) and ε (hep)] as are formed by cold-working hydrogen-free austenite at low temperatures (−196 C) (−321 F). No evidence of a hexagonal hydride was found. The formation of the ε phase by cathodic charging suggests that hydrogen lowers the stacking fault energy of austenite. Hydrogen charging expands the austenite lattice, causes the dislocation and stacking fault density to increase with increasing hydrogen concentration, and causes dislocation movement.

Annealing behavior of a ferritic stainless steel subjected to large-strain cold working

2007 ◽  
Vol 22 (11) ◽  
pp. 3042-3051 ◽  
Author(s):  
A. Belyakov ◽  
K. Tsuzaki ◽  
Y. Kimura ◽  
Y. Mishima
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Cold Working ◽  
Large Strain ◽  
Recrystallization Behavior ◽  
Bar Rolling ◽  
Annealing Behavior ◽  
Ultrafine Grained ◽  
Continuous Recrystallization ◽  
Cold Strain

Mechanisms of microstructure evolution during annealing after cold working were studied in an Fe-15%Cr ferritic stainless steel, which was processed by bar rolling/swaging to various total strains ranging from 1.0 to 7.3 at ambient temperature. Two types of recrystallization behavior were observed depending on the cold strain. An ordinary primary (discontinuous) recrystallization developed in the samples processed to conventional strains of 1.0–2.0. On the other hand, rapid recovery at early annealing resulted in ultrafine-grained microstructures in the larger strained samples that continuously coarsened on further annealing. Such annealing behavior was considered as continuous recrystallization.

Effect of Hydrogen Isotopes on the Fracture Toughness Properties of Types 316L and 304L Stainless Steel Forgings

2019 ◽  
Author(s):  
Michael J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Yield Strength ◽  
316L Stainless Steel ◽  
Large Strain ◽  
Hydrogen Isotopes ◽  
High Yield ◽  
304L Stainless Steel ◽  
Type 316L ◽  
Type 316L Stainless Steel

Abstract Forged stainless steels are commonly used for the containment of hydrogen isotopes and fracture toughness properties are needed for structural integrity assessments. In this study, the effects of hydrogen and tritium precharging on the fracture-toughness properties of Types 316L and 304L stainless steel forgings were measured. The purpose of the study was to evaluate hydrogen and tritium effects on fracture toughness properties of: (1) Type 316 stainless steel stem-shaped and cup shaped forgings; and (2) Type 304L cylindrical block forgings with two different yield strengths. Arc-shaped fracture toughness specimens were cut from the forgings and precharged by exposing the specimens to hydrogen or tritium gas at 623K and 34.5 MPa. Tritium precharged specimens were aged at 193 K for 45 months prior to testing to build-in helium-3 from tritium decay. In the as-received condition, the J-Integral fracture toughness of the stem, cup, and block forgings were very high and exceeded 1200 kJ/m2 on average. The fracture toughness of specimens cut from the low yield strength Type 304L stainless steel block forging had the highest fracture toughness values and Type 316L stainless steel cup forging had the lowest. The reduced fracture toughness values were attributed to the large strain required to produce the cup forging and its high yield strength. Hydrogen precharging reduced the fracture toughness of the stem, cup, and block forgings to values between 34%–51% of a baseline value which was taken to be the fracture toughness value of the low yield strength block forging. Tritium precharging reduced the fracture-toughness values more than hydrogen precharging because of the effects of helium from radioactive decay of tritium. The fracture-toughness properties of tritium-precharged forgings ranged from 12% to 23% of the baseline values. In general, Type 316L stainless steel was more resistant to toughness reductions by hydrogen or tritium (and decay helium) than Type 304L stainless steel. Yield strength had only minor effects on fracture toughness for the precharged steels.

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