Significance of austenite grain size for ultrafine-grained ferrite structure

摘要

By keeping thick plates production by the HDR process in mind, the significance of the #gamma# grain size is studied for producing ultrafine-grained #alpha# structure by heavy deformation. It is concluded that ultrafine-grained #alpha# structure with a grain size smaller than 4 #mu#m can be obtained by applying strains larger than 2 for #gamma# grain size in the range of 17-300 #mu#m. Strain is more important than #gamma# grain size to form ultrafine-grained #alpha# structure.