Coated tool Performance in Dry Turning of Super Duplex Stainless Steel

Abstract

Super duplex stainless steels (SDSS) are widely used in marine environments because of their excellent mechanical properties and corrosion resistance. The presence of different alloying elements and their two phase microstructure makes it a difficult-to- machine material. The use of multilayer coated cutting tools is an effective strategy to improve the cutting performance during dry machining of this material. In this work, the performance of four different coated tools made either by PVD or CVD has been investigated during dry turning of SDSS. Their performances were evaluated in terms of tool wear, cutting force, cutting temperature and surface integrity. Results indicated that [MT-TiCN]-Al2 O3 coating provided relatively better performance than other coatings in terms of tool wear, cutting force and surface integrity. Their combined properties of higher hardness and oxidation stability make them an effective coating during machining The TiN-[MT-TiCN]-Al2 O3 coating exhibited higher tool wear, poor surface finish and also less tensile residual stress in comparison with surfaces machined using other coated tools. This may be due to the dominance of plastic deformation by mechanical load over temperature effects during machining.