Continuous dynamic recrystallization during warm deformation of tempered lath martensite in a medium carbon steel

摘要

To understand the mechanisms of accelerated dynamic recrystallization behavior during the warm deformation of martensites, the tempered lath martensite of 0.4C steel (Fe-0.399%C-1.96%Mn in mass %) was deformed at 650°C in compression to different reductions, and microstructural evolution was investigated. During the deformation, an initial lath martensite structure with a complicated morphology was gradually changed into more equiaxed structure. After 50% reduction and above, an equiaxed, fine grained structure mainly surrounded by high-angle boundaries was uniformly formed with dislocation substructures, where the dislocation density in the grains is relatively low. Since there was no significant boundary migration during this process, this microstructural evolution can be termed as continuous dynamic recrystallization.