Creep After Cyclic-Plasticity Under Multiaxial Conditions for Type 316 Stainless Steel at Elevated Temperature

1990 ◽  
Vol 112 (3) ◽  
pp. 346-352 ◽  
Author(s):  
S. Murakami ◽  
M. Kawai ◽  
Y. Yamada
Keyword(s):  
Stainless Steel ◽  
Uniaxial Tension ◽  
Flow Direction ◽  
Cyclic Plasticity ◽  
Total Strain Amplitude ◽  
316 Stainless Steel ◽  
Creep Flow ◽  
History Effects ◽  
Simple Tension ◽  
Strain Paths

History effects of cyclic-plasticity on subsequent creep have been elucidated for type 316 stainless steel at 600°C under multiaxial states of stress. Tension-compression and circular strain paths were specified for the prior cyclic plasticity. Constant stress creep experiments under simple tension, simple torsion, and combined tensiontorsion were first performed after uniaxial tension-compression cycles stabilized under a constant total strain amplitude. Then, in order to elucidate the path shape effects of prior strain cycles, the subsequent creep curves under uniaxial tension were compared for the uniaxial tension-compression and the non-proportional circular strain cycles which stabilized at identical stress amplitudes. The experimental results showed that the prior tension-compression cycles induced the anisotropy in creep behavior; creep resistance which was initially isotropic was enhanced in torsional direction, while it was decreased in tensile one. Another significant observation was that the circular strain cycles showed much larger hardening effect on creep than the tension-compression cycle. Regarding the creep flow direction, the effect of the prior cycles was negligible.

Temperature-Dependence of Multiaxial Non-Proportional Cyclic Behavior of Type 316 Stainless Steel

1989 ◽  
Vol 111 (1) ◽  
pp. 32-39 ◽  
Author(s):  
S. Murakami ◽  
M. Kawai ◽  
K. Aoki ◽  
Y. Ohmi
Keyword(s):  
Stainless Steel ◽  
Temperature Dependence ◽  
Uniaxial Tension ◽  
Constant Strain Rate ◽  
Inelastic Strain ◽  
Cyclic Hardening ◽  
Material Behavior ◽  
Cyclic Behavior ◽  
316 Stainless Steel ◽  
Strain Paths

Temperature dependence of multiaxial cyclic behavior of type 316 stainless steel was elucidated experimentally. Cyclic tests under constant total-strain amplitudes were performed for uniaxial tension-compression and circular (non-proportional) strain paths at several temperatures; room temperature, 200°C, 400°C, 500°C, 600°C, and 700°C. The strain amplitudes of the cycles were specified to be 0.2, 0.3, and 0.4 percent under constant strain rate of 0.2 percent per min. A quantitative discussion was made with special emphasis on the difference between material behavior under uniaxial tension-compression strain cycles and multiaxial non-proportional circular ones at these temperatures. The most significant cyclic hardening was observed in the temperature range between 400°C and 600°C for both the proportional and the non-proportional strain cycles. At these particular temperatures, much larger inelastic strain was accumulated until a cyclic stabilization was obtained. Though the effect of non-proportionality in the cyclic strain paths on the cyclic hardening was significant particularly at the temperature below 450°C, it rapdily decreased at higher temperatures.

Low Cycle Fatigue Life of Type 316 Stainless Steel Notched Specimen Under Proportional and Non-Proportional Multiaxial Loadings

2010 ◽  
Author(s):  
Takamoto Itoh
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Strain Path ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Notched Specimen ◽  
Life Estimation ◽  
316 Stainless Steel ◽  
Strain Parameter ◽  
Strain Paths

This study discusses multiaxial low cycle fatigue life of notched specimen under proportional and non-proportional loadings at room temperature. Strain controlled multiaxial low cycle fatigue tests were carried out using smooth and circumferentially notched round-bar specimens of type 316 stainless steel. Four kinds of notched specimens were employed of which elastic stress concentration factors, Kt, are 1.5, 2.5, 4.2 and 6.0. The strain paths include proportional and non-proportional loadings. The former employed a push-pull straining or a reversed torsion straining. The latter was achieved by strain path where axial and shear strains has 90 degree phase difference but their amplitudes is the same based on von Mises’ criterion. The notch dependency of multiaxial low cycle fatigue life and the life estimation are discussed. The lives depend on both Kt and strain path. The strain parameter for the life estimation is also discussed with the non-proportional strain parameter proposed by the author with introducing Kt. The proposed parameter gives a satisfactory correlation with multiaxial low cycle fatigue life of notched specimen of type 316 stainless steel under proportional and non-proportional loadings.

Effects of Amplitude-History and Temperature-History on Multiaxial Cyclic Behavior of Type 316 Stainless Steel

1989 ◽  
Vol 111 (3) ◽  
pp. 278-285 ◽  
Author(s):  
S. Murakami ◽  
M. Kawai ◽  
Y. Ohmi
Keyword(s):  
Stainless Steel ◽  
Strain Amplitude ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Cyclic Behavior ◽  
Temperature History ◽  
316 Stainless Steel ◽  
Definite Effect ◽  
Strain Paths ◽  
Higher Temperature

The effects of the history in strain-amplitude and temperature variation on the multiaxial cyclic behavior of type 316 stainless steel were discussed by performing a series of total-strain controlled cyclic tests under uniaxial tension-compression and circular strain paths. Constant strain rate of 0.2 percent/min was specified throughout the tests. The effects of strain amplitude history were examined by changing the strain amplitude between 0.2 percent and 0.4 percent (step-up and step-down tests) at room temperature, 400°C and 600°C. For temperature history dependence tests, the temperature was changed between 200°C and 600°C, 400°C and 600°C, 500°C and 600°C, by specifying a constant strain amplitude of 0.3 percent. It was observed that for the step-up change in strain amplitude the prior cycle showed apparently no influence on the subsequent cyclic accommodation for the uniaxial and the multiaxial cycles at room temperature, 400°C and 600°C. For the decrease in strain amplitude, however, the definite effect of the prior cycle was observed at 400°C, while at higher temperature it disappeared. The effect of the temperature history, on the other hand, appeared only in the case of the temperature-decrease during the uniaxial cycle.

Effects of Prior Creep on Subsequent Plasticity of Type 316 Stainless Steel at Elevated Temperature

1983 ◽  
Vol 105 (4) ◽  
pp. 257-263 ◽  
Author(s):  
Y. Ohashi ◽  
M. Kawai ◽  
H. Shimizu
Keyword(s):  
Plastic Deformation ◽  
Stainless Steel ◽  
Elevated Temperature ◽  
Experimental Results ◽  
Marked Influence ◽  
316 Stainless Steel ◽  
History Effects ◽  
Axial Tension ◽  
The One ◽  
Deformation Tests

History effects of prior creep on subsequent plasticity were studied for type 316 stainless steel at 600°C under combined torsion and tension. Following each of three different amounts of prior torsional creep, plastic deformation tests were performed under torsions in the same and opposite directions of the prior creep and axial tension, respectively. The experimental results showed the marked influence of prior creep on subsequent plasticity. That is, the flow stress in the subsequent plastic deformation after creep became larger than the one in the corresponding pure plastic test where the prior creep strain in the combined creep-plasticity test was replaced by a plastic strain of the same amount. Finally, predictions by means of existing separated and unified constitutive equations were discussed on the basis of the experimental results.

Modeling of 316 Stainless Steel (17.12 Sph.) Mechanical Properties Using Biaxial Experiments—Part II: Model and Simulation

1987 ◽  
Vol 109 (4) ◽  
pp. 455-459 ◽  
Author(s):  
P. Delobelle ◽  
C. Oytana
Keyword(s):  
Stainless Steel ◽  
Internal Variable ◽  
Quantitative Agreement ◽  
State Equation ◽  
Complex Stress ◽  
Plastic State ◽  
Internal Variables ◽  
Proportional Loading ◽  
316 Stainless Steel ◽  
Strain Paths

A rheological model aimed at accounting for the existence of two types of viscoplastic flow (microplastic and macroplastic) in 316 stainless steel is described in the most general state of stress. A distribution between active loadings (macroplastic strains) and unloadings (and/or loadings in a microplastic domain) made through a criterion essentially based on internal variables. A single internal variable is introduced in a single plastic state equation, the different behaviors being accounted for by the choice of the internal variable and of its hardening rules. Identification of these hardening laws are reported. It is seen that this model can predict a lot of various experimental observations in tensile, tensile-compression or tensile-compression-torsion tests. Numerical simulations of various tests extending from the tensile one to complex stress or strain paths in biaxial proportional loading are in a good quantitative agreement with the experimental results.

Some aspects of the defect structure in an austenitic stainless steel

1978 ◽  
Vol 36 (1) ◽  
pp. 314-315
Author(s):  
R. Gonzalez ◽  
L. Bru
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cellular Structures ◽  
Total Strain Amplitude ◽  
Total Deformation ◽  
Density Of Dislocations ◽  
Planar Arrays ◽  
Stacking Fault Tetrahedra ◽  
Distribution Of Dislocations ◽  
Very High

The analysis of stacking fault tetrahedra (SFT) in fatigued metals (1,2) is somewhat complicated, due partly to their relatively low density, but principally to the presence of a very high density of dislocations which hides them. In order to overcome this second difficulty, we have used in this work an austenitic stainless steel that deforms in a planar mode and, as expected, examination of the substructure revealed planar arrays of dislocation dipoles rather than the cellular structures which appear both in single and polycrystals of cyclically deformed copper and silver. This more uniform distribution of dislocations allows a better identification of the SFT.The samples were fatigue deformed at the constant total strain amplitude Δε = 0.025 for 5 cycles at three temperatures: 85, 293 and 773 K. One of the samples was tensile strained with a total deformation of 3.5%.

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