Very High Plastic Strain Zones in 304 Stainless Steel Small Punch Specimen Loaded at RT by Martensite Formation and Recrystallization Technique

2014 ◽  
Vol 627 ◽  
pp. 429-432
Author(s):  
Y. Iino ◽  
Hyu Sun Yu ◽  
J.H. Kong ◽  
Masahiro Okumiya
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Contact Region ◽  
Equivalent Plastic Strain ◽  
304 Stainless Steel ◽  
Martensite Formation ◽  
Small Punch ◽  
High Plastic Strain ◽  
High Plastic ◽  
Very High

Very high plastic strain zones with equivalent plastic strain above 0.2, PZ0.2 and above 0.5, PZ0.5 in 304 stainless steel small punch specimens loaded at RT to various level were observed and measured by martensite formation and recrystallization technique, respectively. It is found that both the very high plastic zones are formed ,at middle stage of the small punch test, at first near the outer surface region of the specimen where the loading ball is contacted to the specimen. The zones extend with increasing load toward the inner surface. Thus the contact area part of the specimen with the ball causes a significant strain gradient through thickness. This will be due to the constraint of the plastic deformation near the contact region by the friction force.

Recrystallization Technique of Plastic and High Strain Zones and Fracture in Small Punch Specimen Loaded at Rt and 77K of 304 Stainless Steel

2013 ◽  
Vol 577-578 ◽  
pp. 305-308 ◽  
Author(s):  
Y. Iino ◽  
Hyu Sun Yu ◽  
T.Y. Kim ◽  
S.H. Chung
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Plastic Zone ◽  
Martensite Transformation ◽  
High Strain ◽  
Equivalent Plastic Strain ◽  
304 Stainless Steel ◽  
Small Punch ◽  
Bending Mode

Plastic zone with equivalent plastic strain ε above 0.02 PZ0.02 and that above 0.12 PZ0.12 in 304 stainless steel small punch specimen loaded at RT and 77K to various level to fracture were measured by the recrystallization technique. Martensite transformation was also checked magnetically. It is found that the behaviour of both PZ0.02 and PZ 0.12 is at first stretching mode, then stretching and bending mode and then stretching mode. PZ0.02 and PZ0.12 propagated to the clamped region of the specimen.

An Experimental Study on the Effect of Prior Plastic Straining on Creep Behavior of 304 Stainless Steel

1993 ◽  
Vol 115 (2) ◽  
pp. 200-203 ◽  
Author(s):  
Z. Xia ◽  
F. Ellyin
Keyword(s):  
Stainless Steel ◽  
Plastic Strain ◽  
Strain Rate ◽  
Creep Behavior ◽  
Test Procedure ◽  
Constant Strain Rate ◽  
304 Stainless Steel ◽  
Creep Model ◽  
Plastic Strain Rate ◽  
Creep Tests

Constant strain-rate plastic straining followed by creep tests were conducted to investigate the effect of prior plastic straining on the subsequent creep behavior of 304 stainless steel at room temperature. The effects of plastic strain and plastic strain-rate were delineated by a specially designed test procedure, and it is found that both factors have a strong influence on the subsequent creep deformation. A creep model combining the two factors is then developed. The predictions of the model are in good agreement with the test results.

scholarly journals High Plastic Strain of Silica Microparticles under Electron Beam Irradiation

2014 ◽  
Vol 20 (S3) ◽  
pp. 1544-1545 ◽  
Author(s):  
Douglas Stauffer ◽  
Sanjit Bhowmick ◽  
Ryan Major ◽  
Oden L. Warren ◽  
S. A. Syed Asif
Keyword(s):  
Electron Beam ◽  
Plastic Strain ◽  
Electron Beam Irradiation ◽  
Beam Irradiation ◽  
Silica Microparticles ◽  
High Plastic Strain ◽  
High Plastic

High Temperature Low-Cycle Fatigue, Deformation Microstructure and Final Fracture Behavior of a Nickel-Base Superalloy

2008 ◽  
Vol 378-379 ◽  
pp. 249-270 ◽  
Author(s):  
Du Yi Ye ◽  
Jin Yang Zheng
Keyword(s):  
Plastic Strain ◽  
Crack Propagation ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Cycle Fatigue ◽  
Final Fracture ◽  
High Plastic Strain ◽  
Nickel Base ◽  
High Plastic

The low-cycle fatigue (LCF) properties of a nickel-base precipitation-strengthened superalloy (GH4145/SQ), obtained at a temperature of 538 o C, were reported and discussed in this paper. The properties investigated include cyclic stress response, fatigue life, deformation microstructure and final fracture features as a function of applied strain amplitude. It was shown that the alloy exhibited a pronounced initial hardening followed by continuous softening to failure at high plastic strain amplitudes ( > 0.2% ap ε ), while at low plastic strain amplitudes ( < 0.2% ap ε ) the initial hardening was followed by a well-defined saturation stage. Bilinear behavior with a change of slope at a plastic strain amplitude of about 0.2% was observed in the cyclic stress-strain (CSS) and Coffin-Manson (C-M) plots. TEM observations revealed that slip band density increased with increasing total strain amplitude and precipitate degradation resulting from dislocation-precipitate interactions took place with continuous cyclic straining. The change in the microstructure during cycling is thus responsible for the fatigue hardening / softening behavior of the alloy. SEM examinations indicated that at low plastic strain amplitudes ( < 0.2% ap ε ) crack propagation was basically transgranular, while at high plastic strain amplitudes ( > 0.2% ap ε ) crack propagation exhibited intergranular features, as a whole. The variation in both the number of operating slip systems and the fracture modes with the strain amplitude employed was used to explain the observed two-stage LCF behavior of the present investigated superalloy.

Sign in / Sign up

Export Citation Format

Share Document