Cyclic accumulation of the inelastic strain in the 304L SS under stress control at room temperature: Ratcheting or creep?

The main objective of the work is to investigate the importance of time dependent phenomena in the cyclic behavior of the 304L SS at room temperature. The contribution of creep in the cyclic evolution of the inelastic strain observed under stress control is particularly studied through various tests using proportional and non proportional loading paths. The test results demonstrate that the behavior is strongly rate dependent. Moreover, most of the cyclic accumulation of the inelastic strain is due to creep which implies that ratcheting is very small for the different conditions considered. The study clearly shows that a correct description of the behavior of the 304L SS at room temperature cannot be obtained without time-dependent constitutive equations. The tests performed have been simulated with the multimechanism constitutive equations after the identification of its 17 parameters. The quality of the simulations is in good agreement with the experimental results especially for the non proportional loading paths.