Comparison of Ferrite Refinement Mechanisms by Different rnProcessing Schedules in 08 and 20Mn Steels

摘要

The influence of deforming temperature on ferrite refinementrn was analyzed by comparing the microstructures obtained by deformationrn at above Ar3, in two-phase region of (+) and at below A1 in clean 08 rnand 20Mn steels. The results indicate that ferrite refinement through rnstrain induced transformation by deformation at above Ar3 is more effernctive than that by deformation simply through ferrite dynamic recrystarnllization. The main problem of ferrite refinement by deformation at bernlow Ar3 is the inhomogeneity of microstructure which is controlled by rnthe orientations and sizes of ferrite grains and the distribution of srnecond phases. Ferrite dynamic recrystallization after strain induced trnransformation can further effectively refine ferrite.