| 摘要 |
Coated cemented carbide inserts for short hole drilling in steel at high speed and moderate feed is disclosed. The cemented carbide includes WC, about 2-10 wt-% Co, and about 4-12 wt-% cubic carbides of metals from groups IVa, Va or VIa. The Co-binder phase is highly alloyed with W with a CW-ratio of about 0.75-0.90. The insert has a binder phase enriched and essentially cubic carbide free surface zone of a thickness of less than about 20 mum. Along a line essentially bisecting the edge in the direction from the edge to the centre of the insert, a binder phase content increases essentially monotonously until it reaches the bulk composition. Binder phase content at the edge in vol-% is about 0.65-0.75 times binder phase content of the bulk. The depth of the binder phase depletion is about 100-300 mum. |
