Effect of microstructure prior to cold-rolling on planar anisotropy of r-value in cold-rolled high carbon steel sheets

The effect of the microstructure prior to cold rolling on the recrystallization texture and planar anisotropy of the r-value (Deltar) in JIS S35C cold-rolled high carbon steel sheet were investigated. When the structure contains fine spheroidized cementite prior to cold rolling, recrystallization is retarded and takes the form of in-situ recrystallization. However, with coarse cementite, recrystallization is completed at a low temperature, and in subsequent grain growth, Ostwald growth of cementite is rate-governing. This difference in recrystallization behavior is inferred to be caused by differences in both the size and the distribution of cementite. Deltar in smaller with fine spheroidized cementite than with coarse spheroidized cementites. This is thought to be caused by both the strong development of gamma-fiber (<111>//ND) grains in the recrystallization texture and retardation of {110} grains, which reduce Deltar, during annealing. Therefore, it is inferred that refinement of cementite prior to cold rolling contributes to the improvement of the recrystallization texture as it affects Deltar.