Quantitative evaluation of experimental wear behaviour for CrN-coated tool steels in sheet metal forming process of TRIP 1180

Abstract The damage to the tool surface earlier than expected in the sheet metal forming process of ultra high strength steel (UHSS) sheet is due to the high reaction force of the materials, which is directly related to the decrease of productivity and product quality and increase the maintenance cost of the forming tool. In this study, the wear behaviour of the tool surface was quantitatively analysed by experimental database. The contact conditions of the tool surface in the sheet metal forming process was confirmed by finite element analysis. Based on this analysis of contact characteristics, continuous wear tests with UHSS sheet were conducted with progressive punch and die sets. The quantitative wear behaviour of the tool was evaluated by measuring the wear depth of the tool and the roughness of the tools and the products. The effect and sensitivity of tool wear for tool-making and process conditions were quantitatively analysed through the experimental database of tool wear per hits.