Dynamic observation of twin evolution during austenite grain growth in an Fe–C–Mn–Si alloy

Abstract

Abstract For the first time, investigation of twin evolution during austenite grain growth in an Fe–C–Mn–Si alloy was conducted with in-situ observation using high temperature laser scanning confocal microscopy during austenization. It was found that twins nucleated in austenite grains, some of which might disappear during isothermal holding, even as new twins might nucleate at grain boundaries. In addition, the effects of twins and austenite grains on bainite morphology were also examined. The twins can restrain the growth of bainite sheaves and smaller austenite grains result in shorter bainite laths. The investigation of dynamic evolution of twins and the analysis of the effect of austenite twins on bainite morphology can only be realized by means of in-situ observation.