Metal Cutting Performance of Carbon-Free PM Tool Steels Fe-Co-Mo

摘要

Carbon-free precipitation hardened Fe-Co-Mo tool steels exhibit higher resistance to heat softeningthan classical carbidic high speed steels. In the present study, Fe-Co-Mo in a monolithic variant andparticle reinforced with Al_2O_3 was prepared by mixing, pressing and sintering with subsequent hotrolling. After shaping the specimens and heat treatment, preliminary turning and milling tests wereperformed against different steel grades. It showed that compared to carbidic tool steel M42 the Fe-Co-Mo steel exhibited markedly higher performance in cutting of both carbon steel and austeniticgrade 304L in which cases thermal softening is the main failure mechanism; here, heat treatment, inparticular secondary hardening, is crucial. Cutting of high-Cr tool steel on the other hand resulted inconsiderable abrasive wear, caused by the coarse M_7C_3 carbides in the workpiece. In this case,particle reinforcing with Al_2O_3 proved to be a promising approach.