Abstract: A coated cemented carbide insert is particularly useful for wet or dry milling steels at high cutting speeds, milling of hardened steels, and high feed copy milling of tool steels. The insert is formed by a cemented carbide body including WC, NbC and TaC, a W-alloyed Co binder phase, and a coating including an innermost layer of TiCxNyOz, with equiaxed grains, a layer of TiCxNyOz with columnar grains and a layer of ?-Al2O3.

Abstract: A cutting insert preferably for milling of extremely highly alloyed grey cast iron, of a substrate and a coating and methods of making and using the insert are disclosed. The cemented carbide substrate includes WC, of from about 3 to about 8 weight-% Co and less than about 0.5 weight-% carbides of metals from groups IVb, Vb or VIb of the periodic table. The coating has a first, innermost layer of TiCxNyOz with x+y+z=1, y>x and z less than about 0.2, preferably y greater than about 0.8, and z=0, with equiaxed grains with size less than about 0.5 ?m and a total thickness of from about 0.1 to about 1.5 ?m, a layer of TiCxNy with x+y=1, x greater than about 0.3 and y greater than about 0.3, preferably x greater than or equal to about 0.5, with a thickness of greater than about 3 to about 5 ?m with columnar grains with an average diameter of less than about 5 ?m, a layer of a smooth, fine-grained, grain size of from about 0.5 to about 2 ?m, ?-Al2O3 with a thickness of from about 0.

Abstract: Coated milling inserts particularly useful for milling of highly alloyed grey cast iron with or without cast skin under wet conditions at preferably rather high cutting speeds and milling of nodular cast iron and compacted graphite iron with or without cast skin under wet conditions at moderate cutting speeds are disclosed. The inserts are characterised by a WC—Co cemented carbide with a low content of cubic carbides and a highly W-alloyed binder phase and a coating including an inner layer of TiCxNy with columnar grains followed by a layer of ?-Al2O3 and a top layer of TiN.