SURFACE COATED HIGH SPEED TOOL STEEL GEAR CUTTING TOOL EXHIBITING EXCELLENT CHIPPING RESISTANCE OF HARD COATING LAYER IN HIGH-SPEED GEAR CUTTING OF ALLOY-STEEL

摘要

PROBLEM TO BE SOLVED: To provide a surface coated high speed tool steel gear cutting tool exhibiting excellent chipping resistance of hard coating layer in high-speed gear cutting of alloy-steel.;SOLUTION: In this gear cutting tool, (a) an upper layer and a lower layer which are both formed of (Cr, Al, Si)N are formed on the surface of a gear cutting tool body formed of high-speed tool steel, the upper layer has a layer thickness of 0.5 to 1.5 μm and the lower layer has a layer thickness of 2 to 6 μm. (b) The upper layer has an alternately stacking structure of a thin layer A and a thin layer B which both have a layer thickness of 5 to 20 nm, the thin layer A is formed of (Cr, Al, Si)N layer satisfying the expression (Cr₁-_(A+B)Al_ASi_B)N, and the thin layer B is formed of (Cr, Al, Si)N layer satisfying the expression (Cr_1-(C+D)Al_CSi_D)N. (c) The lower layer has a single phase structure, and it is formed by depositing a hard coating layer formed of (Cr, Al, Si)N layer satisfying the expression (Cr_1-(E+F)Al_ESi_F)N.;COPYRIGHT: (C)2007,JPO&INPIT