Effects of Carbon and Manganese on the Deep-drawability of Cold-rolled Steel Sheets

Abstract

Effects of carbon, manganese, and their mutual interaction on the recrystallization texture and deepdrawability (r-value) of cold rolled steels have been studied. Hot bands with various carbon content and carbide morphology were cold-rolled by a reduction of 75%, heated at two different heating rates (100°C/h and 50°C/s), and annealed at 700°C. The results showed that the interaction between carbon and manganese played a significant role in the formation of recrystallization texture: the r-value decreased markedly by the co-existence of solute carbon and manganese, while it did slightly by either of them alone, as in 0.001%C steels or 0.03%Mn steels. The decrease in r-value corresponded to a randomization of the recrystallization texture. The above interaction was found to exert an effect on recovery of substructure, weakening the selectivity in the orientation of recrystallization nuclei.
The improvement of r-value under the combination of coarsening of cementite in hot band by high temperature coiling and rapid heating annealing is fully explained by decline of the interaction between solute carbon and manganese resulting from the retarded dissolution of carbide.