Static recrystallisation study of as-cast austenitic stainless steel

Abstract

This investigation will assist the generation of the fundamental knowledge required to develop advanced high strength and formable steels using thin strip casting processes. During thin strip casting the low temperature, high strain rate and the lack of deformation that can be applied in a hot rolling pass may not be sufficient for the onset of dynamic recrystallisation (DRX). Therefore, the refinement of the hot rolled deformed microstructure has to be finished by post-dynamic softening events (metadynamic and/or static). The present investigation reveals the softening mechanisms of as-cast austenitic stainless steel after hot rolling based on static recrystallisation. The static recrystallisation kinetics of austenitic stainless steel can be successfully modelled using a standard Avrami equation with an Avrami exponent of 1.15. It is observed that static recrystallisation proceeds heterogeneously, as a result of a non-uniform distribution of stored energy in the deformed material. The presence of many annealing twins inside recrystallised grains is also observed.