Development of a Tribological Test Programme Based on Press Hardening Simulations

Press hardening is widely utilized to form ultra-high-strength steels characterized by a high strength-to-weight ratio for automotive components. Press hardening processes include heating boron–manganese steels to austenite phase, forming the steels at a high temperature, and cooling the formed blanks until the martensite phase is reached . However, press hardening processes lead to severe contact conditions between the blank and the tools including contact pressure, relative sliding, and high temperatures, which result in tool wear and increased maintenance cost. The contact conditions that occur in the stamping tool are difficult to study on site. Additionally, simplified tests, such as pin on disc and ball on disc, are insufficient to reproduce press hardening conditions in laboratory environments . The aim of this study includes developing a tribological test with press hardening conditions in which tool steel pins continuously slide on fresh and hot boron–manganese steel strips. The test programme mimics press hardening conditions with respect to sliding distance, sliding velocity, contact pressure, and surface temperature that were studied based on finite element (FE) simulations of a press hardening experiment. Furthermore, a FE simulation of the tribological test is established and it provides contact temperature in the pin tip with a high accuracy. A tribological test is used to study friction and mass loss with variational pressures and velocities that represented typically variational contact conditions in the press hardening. The tribological test is also used to obtain correlations between the tribological behaviours and process parameters in press hardening including pressure and sliding velocity.<p>Validerad; 2017; Nivå 2; 2017-03-02 (andbra)</p>FF