Comparative Investigations of Tool Wear and Cutting Force for Wet and Dry Turning of Super Duplex Stainless Steels 2507

<div>Super Duplex Stainless Steels (SDSS) are attracting attentions of the manufacturing industries due to the excellent corrosion resistance to critical corrosion. But SDSS2507 is the hardest to machine with lowest machinability index among DSS family. Moreover, formation of built-up layer (BUL) and work hardening tendency makes it further difficult to machine. Researchers have the conflict in opinions on using wet machining or dry machining using tool coatings. In this investigation SDSS2507 machining is carried out using uncoated and PVD–TiAlSiN-coated tools. The wet and dry machining environment are compared for increase in cutting speed from 170 m/min to 230 m/min. Excellent properties of PVD–TiAlSiN coatings exhibited microhardness of 39 GPa and adhesion strength of 88 N, which outperformed the uncoated tools. Tool life exhibited by coated tools was four times higher than uncoated tools. Wet machining was found to be ineffective when PVD-coated tools are used, exhibiting the same performance as that of dry machining. Dry machining can be preferred for the machining SDSS2507 with PVD–TiAlSiN-coated tools, eliminating the cost of cutting fluids with enhanced productivity.</div>