| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool made from cemented carbide, which is superior in thermal crack resistance and chipping resistance.SOLUTION: The surface-coated cutting tool made from the cemented carbide includes: a tool substrate made from a WC-base cemented carbide which contains at least WC as a hard phase, and Co and Cr as components for forming a binder phase; and a hard coating layer formed on a surface of the tool substrate with a vapor deposition process. A value of a ratio of a Cr content (Cs) in the binder phase in a surface region from the cemented carbide surface to a depth of 200 μm with respect to the Cr content (Ci) in the binder phase in the inner region at a depth of 200 μm or more from the cemented carbide surface satisfies Cs/Ci=1.2 to 1.5. Thereby, the thermal crack resistance in the surface region is improved, at the same time, the propagation of the thermal crack is suppressed in the inner region, and the chipping resistance is also improved. |
