To provide a gear cutting tool made of surface coated high speed steel with hard coating layer exhibiting excellent lubricity in high speed dry gear cutting.
A gear cutting tool is constituted of an upper layer and a lower layer composed of (a) (Ti, Al, V)N on the surface of a base body of a high speed tool steel, the upper layer has a film thickness of 0.5 to 1.5 μm and the lower layer has a film thickness of 2 to 6 μm, respectively. (b) The upper layer has an alternate structure of a thin layer A and a thin layer B having a layer thickness of 5 to 20 nm laminated alternately, and the thin layer A is composed of a (Ti, Al, V)N layer satisfying a composition formula, (Ti1-(A+B)AlAVB)N (wherein A shows a range of 0.01 to 0.10, and B shows a range of 0.50 to 0.70 by atomic ratio), and the thin layer B is composed of a (Ti, Al, V)N layer satisfying a composition formula, (Ti1-(C+D)AlCVD)N. (c) The upper lower layer has a single-phase structure, and is formed by depositing and forming a hard coated layer composed of a (Ti, Al, V)N layer satisfying a composition formula, (Ti1-(E+F)AlEVF)N.
ICHINOMIYA NATSUKI
TANAKA YUSUKE
MITSUBISHI MATERIALS CORP
Kutaro Kamoi