EXPERIMENTAL INVESTIGATIONS ON SURFACE ROUGHNESS, CUTTING FORCES AND TOOL WEAR IN TURNING OF SUPER DUPLEX STAINLESS STEEL WITH COATED CARBIDE INSERTS

This paper addresses experimental investigations of turning Super Duplex Stainless Steel (DSS) with uncoated and Physical Vapor Deposition PVD coated carbide inserts under dry cutting condition. The parametric influence of cutting speed, feed and depth of cut on the surface finish and machinability aspects such as cutting force and tool wear are studied and conclusions are drawn. The turning parameters considered are cutting speed of 60- 360 m/min, feed of 0.05- 0.35 mm/rev and depth of cut of 0.5- 2 mm. Tool wear was analysed by using an optical microscope and scanning electron microscope. The study includes identification of tool wear mechanism occurring on the flank face. The characterization of the coating was made by Calo test for measurement of coating thickness and nanoindentation for hardness. Comparison of performance of PVD coatings TiA1SiN (3.3 mu m), A1TiN (3 gm) and A1TiN (7 gm) have been made in terms of tool life. The coatings were produced on P-grade tungsten carbide inserts by using High Power Impulse Magnetron Sputtering (HiPIMS) technology. The findings of the study also provide the economic solution in case of dry turning of super DSS.