Influence of Conformal Cooling Channel Parameters on Hot Stamping Tool and Press-Hardening Process

Abstract

Press hardening is a technology increasingly used in the automotive industries to produce high-strength structural parts in boron steel. The part strengthening is due to a martensitic microstructure, which is obtained during the quenching phase of the process by imposing cooling rates typically higher than 27 K/s. To improve cooling efficiency, conformal cooling channels (CCC) are increasingly adopting thanks to opportunities offered by additive manufacturing (AM) technologies in combination with the development of powders with high thermal conductivity.In this work a methodology for the design of CCC inside hot stamping tools is presented and the press hardening of an automotive B-Pillar in 22MnB5 has been used as case study. The proposed methodology provides for an optimization of the distance between the cooling channels (p) and distance between the tool surface and the cooling channel center (d).