摘要 |
PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated high speed tool steel having a hard coating layer exhibiting excellent chipping resistance in high-speed heavy cutting of material hard to cut. SOLUTION: In this cutting tool made of surface coated high speed tool steel, the surface of the high speed tool steel substrate includes (a) an upper layer and a lower layer, wherein the upper layer has the average layer thickness ranging from 0.5 to 1.5μm, the lower layer has the average layer thickness ranging from 2 to 6μm, (b) the upper layer has an alternately laminating structure of a thin layer A and a thin layer B, which respectively have the average layer thickness per layer ranging from 5 to 20 nm, and (c) the lower layer has a single phase structure. COPYRIGHT: (C)2007,JPO&INPIT
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