Deformation-induced martensite and its reversion to austenite in an Fe–16Cr–12Ni alloy

Abstract

An investigation has been made of martensite (α′) formed in an Fe–16Cr–12Ni alloy by deformation of austenite (γ) and also of the reversion of α′ to γ resulting from heating deformed material. Deformation was carried out by rolling to 50% reduction at various temperatures in the range +150° to −78°C. The amount of α′ formed increased with decreasing deformation temperature up to ∼85% α′ at −78°C. Hardness measurements and electron microscopic examination were used to study the reversion of α′ to γ and the recovery and recrystallization of γ in samples heated for short times in the range 600°–800°C. The results indicated that recrystallization occurred more rapidly and recovery less rapidly in work-hardened retained γ as compared with reversed γ. The annealing of material containing a high proportion of deformation-induced α′ led to the formation of fine-grained austenite.