| 摘要 |
PROBLEM TO BE SOLVED: To improve the toughness characteristic of cutting inserts for steel machining that include a cemented carbide body and a coating. SOLUTION: A cemented carbide body comprises WC, Co in an amount of 5 to 12% by mass, and cubic carbide of Ta, Ti and W in an amount of 3 to 11% by mass. The content of Nb is not more than 0.1% by mass. A Ta/Ti ratiio is between 1.0 and 4.0. The binder phase of Co is alloyed more with W so that a CW ratio lies between 0.75 and 0.95. The cemented carbide body has a surface region of a thickness of 5 to 50μm which has the binder phase enriched and is substantially free of a gamma phase. |
