Cutting Force and Tool Wear in Face Milling of Hardened Steel

Abstract

In the present study, face milling of AISI H13 steel (46-47 HRC) with CBN tools was conducted. Cutting speeds 389 and 1592 m/min were adopted in order to identify the characteristics of cutting force and tool wear at low and high cutting speeds. For each cutting speed, the metal removal rate and axial depth of cut were set to be invariable, and different combinations of radial depth of cut and feed per tooth were selected. The optimum combination of radial depth of cut and feed per tooth for each cutting speed was distinguished. For different cutting speeds, the cutting force changed in varying ways with different combinations of cutting parameters. At the cutting speed of 389 m/min, after the initial cutting stage, the tool wear rate was low even at the end of tool life. When the cutting speed was 1592 m/min, the tool wear increased rapidly, and the tool wear rate changed little in the whole tool life span. Adhesion and abrasion were the main wear mechanisms of the tool faces at the cutting speed of 389 m/min. While at the cutting speed of 1592 m/min, fracture contributed greatly to the final tool failure.