A CEMENTED CARBIDE INSERT FOR TURNING

摘要

The present invention relates to a cutting insert for turning in steel, stainless steel and heat resistant super alloys comprising a substrate and a coating. The insert has a rake face (1), a flank face (2), cutting edges (3) and a cutting corner (4). The cemented carbide substrate comprises WC, 8.5- 11.5 wt-% Co and 0.8-1.2 wt-% Cr with a coercivity of 19-23 kA/m and a CW_Cr-ratio of 0.80-0.97. The coating comprises an inner (A1, Ti) N- layer, with a thickness of 1-8 µm, and a composition of AlyTi1-yN, where y = 0.30-0.50, and a (AI, Cr) O- layer with a thickness of 0.2-1.5 µm and a composition of (AlxCrI-X)2O3, where x = 0.5-0.9. Inserts according to the invention has high resistance against crater and flank wear as well as improved cutting edge toughness without any loss of plastic deformation resistance. The invention also relates to a method of making the insert by using cathodic arc evaporation or magnetron sputtering. It also relates to the use of the insert for turning in steel, stainless steel and heat resistant super alloy.