Modelling of machining parameters and cooling conditions in hard turning of AISI p-20 tool steel using response surface methodology and desirability graphs

Abstract

This paper presents mathematical models for correlating the CNC machining parameters such as cutting speed, feed rate, depth of cut, nose radius, with the cutting force acting on the cutting tool during turning of prehardened P-20 tool steel. The face centred central composite design module of Response Surface Methodology (RSM) has been used for conducting the experiments. Machining is done under three different environmental conditions - dry, wet (conventional coolant ILO cut 154 Indian Oil) and cryogenic (liquid nitrogen). The significance of the mathematical models developed was ascertained using desirability graph and confirmation experiments. The results obtained show that the mathematical models are useful not only for predicting optimal process parameters for achieving the desired quality but also for achieving the process optimisation. The cutting force contours have been generated from the model equations. Desirability graphs are also drawn giving minimum cutting force a value of one. © 2008, Inderscience Publishers.