Improvement of Machinability of Hardened Steel in Turning Operation Using Cryogenically Treated Cutting Tool

Abstract

Hardened steels need special cutting tools like PCBN and ceramic to be machined. But these cutting tools aren’t cost-effective and require machine tool structures that are stiff and don’t let vibrations through. The current trend is to find other, less expensive ways to make these materials easier to work with. Cryo-treating cutting tools is an effective way to improve the way the tool materials work when they are cut. Cryogenically treated tungsten carbide inserts in dry turning operations were looked at in this study. For hard turning of hardened mild steel (48 HRC), the performance of cryogenically treated Tungsten Carbide (WC) inserts was compared with that of untreated inserts in terms of chip-tool interface temperature and surface roughness under dry cutting conditions. The cutting tool (Untreated and Treated), and cutting speed (375, 512, 706 rpm) were selected as experiment parameters at a constant feed rate of 0.0841mm/rev and depth of cut 1mm. The chip-tool interface temperature analysis results revealed that temperature increases with the increasing cutting velocities. A better surface finish can be found at a higher cutting speed. The lower value of Ra was found at 1.75 μm (without cryogenic treatment) and 1.05 μm (with cryogenic treatment) for cutting speed at 706 rpm.