Ratcheting deformation behavior of 316LN stainless steel under thermomechanical and isothermal loadings

The ratcheting deformation of 316LN stainless steel was investigated under thermomechanical loading where cyclic stress with mean stress and cyclic temperature varying within 250-450 degrees C were simultaneously applied on the specimens. Moreover, the ratcheting tests at a constant temperature of 450 degrees C were also performed. A phenomenon of strain burst caused by dynamic strain aging was observed under in-phase thermomechanical ratcheting tests. The persistent slip markings under various loadings presented a different morphology in early cycling stage, which correspondingly led to the difference in oxidation-assisted cracking mechanisms. In addition, dynamic recrystallization occurred under thermomechanical ratcheting loading.