Tool Wear in Milling Hardened Die Steel

Abstract

Tool wear is an important limiting factor in machining hardened steel. Plane milling of H13 hot work tool steel (42–46 HRC) was conducted on a three-axis machine to obtain flank wear data with the objective of finding operating parameters providing extended tool life. Microgram carbide and PCBN tipped carbide round inserts in an off-center ball nose end mill with a single cutting edge were considered. Tool life was longer for the micrograin carbide inserts when cutting speeds were near 150 m/min. The PCBN grades performed best at the highest speed tested. A limited radial and axial depth of cut with a larger maximum chip thickness provided the best tool life over the parameters tested.