Effect of stress amplitude and stress duration on twinning and phase transformations in shock-loaded and cold-rolled 304 stainless steel

1975 ◽  
Vol 20 ◽  
pp. 35-46 ◽  
Author(s):  
L.E. Murr ◽  
K.P. Staudhammer
Keyword(s):  
Stainless Steel ◽  
Phase Transformations ◽  
Stress Amplitude ◽  
304 Stainless Steel ◽  
Cold Rolled

Effect of Cold Rolling on Sensitization of 304 Stainless Steel Weldments

2013 ◽  
Vol 856 ◽  
pp. 60-63
Author(s):  
M. Milad ◽  
N. Zreiba
Keyword(s):  
Stainless Steel ◽  
Heat Input ◽  
Cold Work ◽  
304 Stainless Steel ◽  
Optimum Level ◽  
Microstructural Investigation ◽  
Welding Heat Input ◽  
Degree Of Sensitization ◽  
Electrochemical Potentiokinetic Reactivation ◽  
Cold Rolled

The sensitization of stainless steel type AISI304 (304SS) is evaluated as a function of pre-welding cold work and welding heat input. 304SS is cold rolled to various percentages of thickness reduction of up to 50% at ambient temperature before being TIG welded. The susceptibility of 304SS to sensitization (weld decay) is evaluated using ASTM A262, practice A and electrochemical potentiokinetic reactivation tests. The results indicate that the influence of pre-welding cold work on the degree of sensitization (DOS) is distinct and appreciable within the range of 10% to 35% CR. In addition, within this range the optimum level of cold work after which the DOS starts to decrease is found to be inversely related to the amount of welding heat input. At higher levels of cold work of ≥ 35% CR, it is found that neither the cold work nor the heat input significantly influences the amount of DOS. Microstructural investigation showed that the predominant intergranular corrosion (IGC) occurs at austenite grain boundaries and less likely at ferrite / austenite interfaces of the weld metal. Meanwhile, transgranular attack at austenite bulk matrix along the defects is rarely observed.

Cyclic Behavior of Reversion-Treated Structures after Different Cold Rolling Reductions in an AISI 301LN Stainless Steel

2018 ◽  
Vol 786 ◽  
pp. 52-56
Author(s):  
Antti Järvenpää ◽  
Matias Jaskari ◽  
Pentti L. Karjalainen
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Cold Rolling ◽  
Stress Amplitude ◽  
Cyclic Hardening ◽  
Coarse Grained ◽  
Cyclic Behavior ◽  
Size Refinement ◽  
Cold Rolling Reduction ◽  
Cold Rolled

Lower cold rolling reductions before reversion annealing for the grain size refinement are desired in industrial practice. This study demonstrates the effect of a low (32%) cold rolling reduction on cyclic behavior of a partially reversed (750 °C for 0.1s) structure in a 17Cr-7Ni-N type 301LN austenitic stainless steel and compares it with those of a 63% cold rolled and annealed and with a conventional coarse-grained structure. Stress amplitude and the amount of deformation-induced martensite formed under cyclic loading at the 0.6% total strain amplitude were recorded. The results showed that the partially reversed structure after the 32% cold rolling reduction exhibits the similar cyclic stress amplitude level and slight cyclic hardening as the 63% cold-rolled counterpart does. Even though the grain size refinement remains less effective at the lower reduction, the microstructure consists of higher fractions of strong retained cold-deformed austenite and martensite phases which increase the flow resistance. However, the coarse-grained structure exhibits a much lower initial stress amplitude and much more pronounced cyclic hardening. The susceptibility of austenite to transform deformation-induced martensite is practically similar among these three structures. However, the cyclic hardening is a caused by the formation of deformation-induced martensite, and the difference in the degree of cyclic hardening results from the big difference in the strength of the austenite between the partially reversed fine-grained and coarse-grained structures.

An Electron Microscope Study of Deformation-Strain Cycling Effects in 304 Stainless Steel

1975 ◽  
Vol 33 ◽  
pp. 42-43
Author(s):  
K.P. Staudhammer ◽  
L.E. Murr
Keyword(s):  
Stainless Steel ◽  
304 Stainless Steel ◽  
Experimental Program ◽  
Residual Structure ◽  
Program Type ◽  
Cold Rolled ◽  
Type 304 ◽  
Type 304 Stainless Steel ◽  
Deformation Modes ◽  
Strain Cycling

While there have been numerous experiments concerned with the effects of cold rolling and shock deformation on stainless steel residual structure, there have been no systematic attempts to investigate the effect of sequencing of these deformation modes for any material.In the present experimental program, type 304 stainless steel sheet was cold rolled (CR) 15 and 30% and incorporated (along with annealed, undeformed specimens) in a sandwich assembly for shock loading (SL), utilizing a flyerplate technique as previously described (at shock pressures of 150, 250, and 350 kilobars, and at a constant shock pulse-duration of 2.0 μ sec.

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