A comparison study of sliding friction behavior between two high strength DP590 steel sheets against heat treated DC53 punch: Hot-dip galvanized sheet versus cold rolled bare sheet

Sliding friction tests were performed to compare the friction behaviors of hot-dip galvanized dual phase sheet (GA-DP590) and cold rolled bare sheet (BARE-DP590). The tests were undertaken with sheet specimens slid against heat treated DC53 punch mounted in a self-developed Tribo-tester to simulate the sliding between the sheets and the forming tool. Results show that the friction coefficients of GA-DP590 sheet are higher than those of BARE-DP590 sheet. The coefficient values of both sheets generally decrease with increasing of the loading, the punch stroke and the sliding speed. However, the frictional coefficients of GA-DP590 can be clearly classified into three stages. SEM observations on the slid sheets were performed to facilitate the understanding of the mechanisms affecting the friction behavior.

► Experimental set-up for simulating the sliding friction between sheet–strip and forming tool.
► Friction coefficients of galvanized GA-DP590 sheet are larger than that of BARE-DP590 sheet.
► Coefficients of BARE-DP590 are in consistent mode.
► “Zn Islands” connecting to the substrate are initially generated in the GA-DP590 coating.