Cemented carbide insert

摘要

The present invention relates to a cutting tool insert for machining of steel comprising a cemented carbide body and a coating. The cemented carbide body comprises WC, 5-12 wt-% Co and 3-11 wt-% cubic carbides of metals Ta, Ti and W. The amount of Nb should be below 0.1 wt-%. The ratio Ta/Ti is 1-4. The Co-binder phase is highly alloyed with W with a CW-ratio of 0.75-0.95. Finally the cemented carbide body has a binder phase enriched and essentially gamma phase free surface zone of a thickness of 5-50 mu m.