INVESTIGATIONS ON FINISH TURNING OF AISI 4340 STEEL IN DIFFERENT CUTTING ENVIRONMENTS BY CBN INSERT

Abstract : This paper presents the effects of minimal quantity lubrication (MQL) on the turning performance of AISI 4340 steel as compared to dry and wet machining in terms of surface roughness, cutting forces and tool wear. Twenty-seven experimental runs were performed based on an orthogonal array of Taguchi method. The effect of cutting speed, feed and cutting environment on tool wear, surface roughness and cutting force of the CBN insert was analysed using analysis of variance (ANOVA) technique and its optimum condition was derived. The Ra values for dry and wet environment were 1.2 μm and 1.1 μm respectively, whereas, in MQL condition it was 0.9 μm. This technique can serve as an environment friendly alternative solution to the conventional dry and wet turning.