A method of modeling residual stresses in superfinish hard turning

It has recently been proven that it is feasible to use hard turning in selected conditions to superfinish surfaces, hardened to 64 Re, to surface finish of 2 mu in., thus making it possible to eliminate the need for separate grinding and abrasive-based superfinish in a broad range of production activities involving hardened workpieces. The surface integrity after machining hardened steel is superior and more consistent than ground and superfinished surfaces [C.R. Liu, S. Mittal, J. MFg. Syst. 14 (2) (1995) 129-133]. It is also known that hard turning produces compressive residual stresses [C.R. Liu, S. Mittal, Robotics Comput, Integr. Manuf. 12 (1) (1996) 15-27] and that machining parameter such as speed, feed and depth of cut effect the residual stress distribution. It is proposed that the residual stress profile is a deterministic function of the machining parameters. It is postulated that the residual stress profile along the depth is a polynomial function of the depth and the coefficients of this polynomial are in turn functions of the machining parameters. The model, with some refinements, has been developed in this paper and has been checked for accuracy. (C) 1998 Elsevier Science S.A. All rights reserved.