CEMENTED CARBIDE INSERTS FOR NOTCH AND WEAR DEMANDING TURNING IN HEAT RESISTANT SUPER ALLOYS (HRSA) AND STAINLESS STEELS

摘要

A cutting tool insert particularly useful for turning of heat resistant super alloys and stainless steels, and a cutting tool insert having a secondary cutting edge with improved wear resistance are provided. A cutting tool insert used for turning of heat resistant super alloys and stainless steels, comprising a substrate and a coating, is characterized in that the substrate comprises 5 to 7 wt.% of Co, preferably 5.8 to 6.2 wt.% of Co, most preferably 6.0 wt.% of Co and 0.15 to 0.60 wt.% of TaC, preferably 0.20 to 0.30 wt.% of TaC and 0.10 to 0.50 wt.% of NbC, preferably 0.10 to 0.20 wt.% of NbC and the balance of WC, and the substrate has a coercivity of 19.5 to 24.5 kA/m, and a CW-ratio of 0.85 to 1.00, preferably 0.9 to 0.98, most preferably 0.92 to 0.97; and the coating comprises a homogeneous AlxTi1-xN layer with x=0.6 to 0.67, preferably x=0.62 and a thickness of greater than 1 mum, preferably greater than 1.8 mum to less than 3.8 mum, preferably less than 3.0 mum.