CYCLIC DEFORMATION OF AISI-310 STAINLESS-STEEL .1. CYCLIC STRESS-STRAIN RESPONSES

Cyclic responses of AISI-310 austenitic stainless steel with coarse grains are investigated in the plastic strain amplitude (ε{lunate}pl) range 1 × 10-4-9 × 10-3. With respect to the cyclic hardening behaviour, three ranges of ε{lunate}pl may be distinguished. ε{lunate}pl < 8 × 10-4: neither cyclic hardening nor cyclic softening is observed; 8 × 10-4 < ε{lunate}pl < 6 × 10-3: a cyclic softening follows a cyclic hardening before the saturation is approached; ε{lunate}pl > 8 × 10-3: a cyclic hardening leads directly to saturation. The cyclic stress-strain (CSS) curve exhibits three regimes of strain dependence of saturation stress (σs): in regime I, σs increases almost unnoticeably with increasing ε{lunate}pl; in regime II, σs increases smoothly with increasing ε{lunate}pl; in regime III, σs increases dramatically with increasing ε{lunate}pl. The three regimes of the CSS curve fall into line with the different ranges of ε{lunate}pl of different cyclic hardening behaviours. © 1990.