电沉积镍涂层, 成形极限, 冲压成形, 应力－应变曲线, 集中失稳

Hill localized instability theory was used to derive the stress-strain equations of nickel coating sheet during forming process. By using polynomial fitting for experimental data, actual stress-strain curves of the electrodeposited nickel coating sheet were obtained. The forming limit left region of the nickel coating sheet was calculated by solving a nonlinear equation, and compared with one by using strain hardening curves. The research results show that the forming limit of the nickel coating by polynomial fitting is higher in security than the one by strain hardening curves, and the substrate anisotropy, coating thickness and substrate thickness have little influences on the formed limit curves. The results may play a directive role on the electrodeposited nickel coating sheet preparation.