Coated cutting tool and method of cutting Ni-base super heat resistant alloy

摘要

PROBLEM TO BE SOLVED: To provide a coated cutting tool having excellent durability and a Ni-base super alloy cutting method using the same in a case of cutting a difficult-to-cut material such as a Ni-base supper alloy.SOLUTION: In a coated cutting tool comprising a base material of a WC-base super alloy, a hard film being coated on a surface of the base material by chemical vapor deposition, the base material has a composition of metallic elements of 4.0%Co6.0%, 0.2%Cr1.0%, and 0.05%Zr0.30% by mass% with a remainder of nonmetallic elements and inevitable impurities present in the metallic elements by solid solution or chemical combination, a hardness is 92.2 HRA to 93.5 HRA, the hard film is a TiCN film, a sectional structure of the TiCN film is constituted by a collection of columnar particles grown generally in a perpendicular direction to the surface of the base material, an average width of the surface-side columnar particles is not more than 0.15 μm, and a residual stress of the hard film is -400 MPa to 400 MPa.