Deformation twin and martensite in the Fe–36%Ni alloy during cryorolling

Abstract

In this paper, the microstructural evolution and deformation mechanism of the cryorolled Fe–36%Ni alloy was investigated. Deformation twinning was confirmed to be activated at the early stage of cryorolling (CR) and subsequently suppressed due to microstructure refinement. The existence of [Formula: see text] and [Formula: see text] peaks revealed that the [Formula: see text] ( α′-M) phase transformation was induced during the CR process. The stress-assisted martensite and strain-induced martensite were detected to be transformed at the grain boundary and intersection of deformation twins, respectively. Owing to the co-effect of the temperature raise and mechanical stabilisation, the α′-M phase transformation was suppressed during the CR process. Therefore, the amount of the α′-M was limited in the tested alloy.