Hot blanking tool wear assessment
Résumé
The trend in the automotive field is to lower the weight and to enhance safety in vehicles. Thecompetitive environment in the sheet metal forming industry leads the manufacturer in an effort to reduce costs. One of the solutions proposed by the automotive industry is the reduction of sheet thickness by using high strength steels (HSS) for structural parts. However because of their mechanical properties, it is easier to form this steel grade by hot stamping and to shear by hot blanking. The blade tools are submitted to high thermo- mechanical stresseswhich induce blade surface damages. The increase of tool lifetimes contributes to cost saving. To assess the wear damage mechanisms of tool grades in the hot blanking process, we propose to study their tribological behaviour with an experimental test based on a hot blanking device simulator. This device is designed to reproduce the shearing of a blank heated at high temperature. After an observation of a part of industrial blade we show that our test device leads to the same wear mechanisms. Blades present adhesive wear from blank coating(Al-Si), plastic deformation and a microstructural evolution.