High‐Temperature Deformation Behavior of Carbon Steel Containing Dispersed Fine Voids

Abstract

Carbon steels either with or without dispersed fine voids were deformed in compression at elevated temperatures and at various strain rates. All the flow curves exhibited typical feature of those accompanied by occurrence of work softening due to dynamic recrystallization. The deformation behavior, however, clearly changed by the presence of voids. The yield stresses and maximum flow stresses of the carbon steel with voids became higher compared with those without voids. Still more, the dispersed fine voids delayed the onset of dynamic recrystallization. The shape and distribution of the voids drastically changed depending on the testing condition, i.e., smaller void size and lower aspect ratio of the void shape were achieved at the lower strain rate and at higher temperature. The effects of the dispersed fine voids on high temperature deformation behavior were discussed in relation with dynamic recrystallization, grain boundary migration, grain boundary sliding and relaxation.