Effect of mean stress and stress amplitude on the ratcheting behaviour of 316LN stainless steel under dynamic strain aging regime.

The influence of dynamic strain aging (DSA) on the ratcheting behaviour of 316LN stainless steel was investigated at 823 K as a function of mean stress (σm) and stress amplitude (σa). Test results obtained under different combinations of σm - σa were analysed in order to arrive at a map delineating different deformation regimes viz. ratcheting, strain burst and elastic shakedown. It was shown that the synergistic effect of σm and σa can be described by the ratio of mean stress and stress amplitude (σm/σa). A critical value of this ratio was identified to mark the transition between ratcheting and elastic shakedown and the same was used to predict deformation behaviour of the material in DSA under asymmetrical loading. [ABSTRACT FROM AUTHOR]