Investigation of Symmetric and Asymmetric Cold Rolling on Steel Strip Microstructure Formation and Hardness

Cold rolling of A57036 steel strip using a 400 SKMZ rolling mill is performed according to two routes: (1) from 8 mm thickness to 2 mm thickness; (2) from 6 mm thickness to 1.5 mm thickness. Rolling is conducted by rolls of equal diameter and with equal angular roll velocity (symmetric rolling), and by rolls of different diameters, different roll angular velocity, but equal roll circumferential speed (asymmetric rolling). Strip microstructure and hardness are measured after rolling in a steady-state stage: measurements are made near the edges and within the center of the upper and lower strip surfaces (6 points for each strip in total). Differences in strip hardness values and microstructure after symmetric and asymmetric rolling are evaluated as a result of the study.