In the present study, the microstructure evolution and material
properties variation mechanism of austenitic stainless steel under
pre-strain were discussed. A bilinear relationship between material
properties and pre-strain was established. Both yield strength and
tensile strength of the austenitic stainless increase with the increase
of pre-strain, but the increment of yield strength is obviously greater
than that of the tensile strength. A critical pre-strain point was put
forward. When the pre-strain is lower than critical value, there is only
work hardening. And when it is higher than critical value, the material
properties are affected by the combined effects of work hardening and
martensitic transformation. The effect of critical pre-strain is also
found in the study of fatigue limit. The inherent essence of fatigue
limit improvement of pre-strained material lies in the comprehensive
effect of material phase transformation and plastic deformation
strengthening.