Cyclic stress-strain behaviour of austenitic Fe-29.7Mn-8.7A1-1.04C alloy at room temperature

Austenitic Fe-29.7Mn-8.7Al-1.04C alloy was cyclically strained at room temperature. The cyclic stress-strain responses of the alloy were examined. At low strain amplitudes the alloy cyclically softened as a result of a rapid decrease in the friction stress. A quasi-plateau region which extended to about 0.75% plastic strain was observed in the cyclic stress-strain curve. Moreover, at higher strain amplitudes the alloy cyclically hardened during the first 16 cycles, but then cyclically softened. The hardening was probably a result of multiple slips and the precipitation of the strain-induced K phase carbides within the matrix. The subsequent softening may be a result of the re-solution or disordering of the ordered K phase carbides within the persistent slip bands. © 1987.