| 摘要 |
PROBLEM TO BE SOLVED: To prevent the cracks and peeling of a hard film in cold tool steel having high hardness by increasing the adhesion between a base material and the hard film. SOLUTION: The cold tool steel is used as the base material 12 of a press die 10, and its surface is provided with a hard film 14 of carbide such as VC and TiC by surface treatment such as CVD. The steel has a composition (a) comprising, as fundamental components, by weight, 1.0 to 2.0% C, 0.01 to 2.0% Si, 0.01 to 2.0% Mn, 6.0 to 12.0% Cr, W and /or Mo satisfying 0.1%≤1/2W+Mo≤4.0%, 0.01 to 1.0% V,≤0.0100% O,≤0.200% N,≤0.050% P and≤0.050% Al, and (b) the balance substantially Fe, wherein (c), when the contents of C and Cr are denoted as [C] and [Cr], respectively, both of 4[C]≤[Cr]≤6[C]+3 and 9≤[C]×[Cr]≤18 are satisfied. COPYRIGHT: (C)2005,JPO&NCIPI
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