ANALASYS OF PROCESS PARAMETERS IN DRY TURNING OF AISI 4140 STEEL BY USING GREY ANALYSIS

AISI 4140 Steel has wide range of applications in the manufacturing industries.It is used for preparing studs, high tensile bolts, riffle barrels and propeller shafts etc.The present work is to investigate the influence of machining parameters on Material Removal Rate and Surface Roughness characteristics Ra, Rq and Rz and Temperature at cutting zone.The experiments were conducted as per standard Taguchi's L9 orthogonal array.For multi objective optimization of the responses, Taguchi based grey relational grade method was adopted.From multi objective grey analysis, the optimal combination of process parameters was found at speed: 130m/min, feed: 0.1 mm/rev, and depth of cut: 0.4 mm.The assumptions of ANOVA like Normal distribution, constant variance and independence of residuals are verified with the residual plots drawn for the responses using MINITAB-17 software.From ANOVA results, it is clear that speed has more significance in affecting the multi responses and followed by depth of cut and feed.The mathematical models were prepared for the individual responses by using regression analysis and a close relation between the predicted values from models and experimental values was observed.