Hard turning of hot work steel AISI H11: Evaluation of cutting pressures, resulting force and temperature

Abstract

The aim of this work is to evaluate cutting pres-sures, resulting force and maximum temperature in hard turning of hot work steel AISI H11. This steel is hardened to 50 HRC, machined by a mixed ceramic tool (insert CC650 of chemical composition 70%Al2O3+30%TiC), free from tungsten on Cr-Mo-V basis, insensitive to tempera-ture changes and having a high wear resistance. It is em-ployed for the manufacture of highly stressed diecasting moulds and inserts with high tool life expectancy, plastic moulds subject to high stress and forging dies. The tests of straight turning were carried out according to the method of planning experiments. The results made it possible to study the influence of cutting variables (feed rate, cutting speed and depth of cut) on cutting pressures, on resulting force and temperature in cutting zone. The effect of flank wear (VB) on cutting pressures is also studied. Mathemati-cal model was deduced to express the influence degree of each cutting regime element on the maximum temperature. Thus, the ranges of best cutting conditions adapted, were given.This study confirms that in dry hard turning of this steel and for all cutting conditions tested, the major pressure is the radial pressure.