Effects of Environment on the Low-Cycle Fatigue Behavior of Type 304 Stainless Steel

摘要

The low-cycle fatigue behavior of Type 304 stainless steel has been investigated at 593 exp 0 C in a dynamic vacuum of better than 1.3 x 10 exp -6 Pa (10 exp -8 torr). The results concerning the effects of strain range, strain rate and tensile hold time on fatigue life are presented and compared with results of similar tests performed in air and sodium environments. Under continuous symmetrical cycling, fatigue life is significantly longer in vacuum than in air; in the low strain range regime, the effect of sodium on fatigue life appears to be similar to that of vacuum. Strain rate (or frequency) strongly influences fatigue life in both air and vacuum. In compressive hold-time tests, the effect of environment on life is similar to that in a continuous-cycling test. However, tensile hold times are nearly as damaging in vacuum as in air. Thus, at least for austenitic stainless steels, the influence of the environment of fatigue life appears to depend on the loading waveshape. (ERA citation 05:020877)