Hybrid laser metal deposition of a Fe–Cr–Mo–V–Mn tool steel for hot stamping applications

In this investigation, a novel Fe–Cr–Mo–V–Mn hot work tool steel powder was specifically developed for laser-based additive manufacturing, targeting the possibility to create conformal cooling channels in hot stamping tools for improved cooling efficiency during the forming of steel sheets for the automotive industry. Specimens of the proposed tool steel were printed via laser metal deposition and characterized to demonstrate its compatibility with hot work tool steels that are commonly used in the tooling industry. The applicability of the developed material was proved by fabricating cooling channels in a simple geometry demonstrator using a hybrid process combining milling and laser metal deposition. Finally, a hybrid-manufactured hot stamping tool segment was tested in a pilot plant to evaluate the effect of the investigated material on the cooling performance when compared to a conventional tool machined from H13 hot work tool steel. The results showed that the Fe–Cr–Mo–V–Mn tool steel features thermophysical properties similar to the most popular H13 steel and it can be efficiently used to produce tools containing conformal cooling channels by hybrid laser metal deposition, without the need of intermediate structures to improve the compatibility between the substrate and the deposited volumes.