Experimental study on ratchetting-fatigue interaction of SS304 stainless steel in uniaxial cyclic stressing

The ratchetting behaviour and fatigue failure, as well as their interaction were investigated by uniaxial cyclic stressing tests for SS304 stainless steel at room temperature. The ratchetting strain and fatigue life of the material were measured in different loading levels. The effects of mean stress, stress amplitude and stress ratio on the ratchetting strain and final failure life were discussed. Simultaneously, the variations of responded strain amplitude with the number of cycles were illustrated to discuss the interaction of ratchetting behaviour and fatigue failure. The experimental results show that the ratchetting strain and fatigue life of the material depend greatly on mean stress, stress amplitude and stress ratio of uniaxial cyclic stressing, and two kinds of failure modes (i.e., ratchetting failure with obvious necking due to large ratchetting strain and fatigue failure due to low-cycle fatigue with nearly constant responded strain amplitude) take place respectively, depending on the stress level prescribed in the tests.