2009 年 50 巻 578 号 p. 232-236
The formability of steels subjected to different cold forming processes was investigated. In this study, the workability of ECAE(Equal channel angular extrusion) processed carbon steel was studied by cold upsetting tests. Three kinds of workpiece were prepared by ECAE process, rolling and combined (ECAE and post rolling) processes. All processes were carried out under the condition at room temperature. Experimental results are evaluated using cumulative equivalent strain. It was observed that the workability of the ECAE processed material was higher than that of the rolled one at the same equivalent strain. The higher workability was due to a continuous dynamic recrystallization which was identified by electron backscatter pattern (EBSP) analysis. The combined process enhanced mechanical properties and maintained good workability even with increasing applied strain, however its mechanism was not clarified.