| 摘要 |
PROBLEM TO BE SOLVED: To provide a nitrided die for warm and hot working, as a die to which nitriding treatment is applied and which has high hardness of nitrided layer and softening resistance of nitrided layer and excellent wear resistance. SOLUTION: The nitrided die for warm and hot working has a composition which consists of, by weight, 0.25-0.55% C, <=1.2% Si, <=1.5% Mn, <=2.0% Ni, 6.0-8.0% Cr, either or both of W and Mo in amounts within the range satisfying 1/2W+Mo<=5.0%, and the balance Fe with inevitable impurities and in which Cr and Mo satisfy Cr/Mo<=3. Moreover, carbides unentered into solid solution with >=0.1μm grain size comprise >=1% of the structure surface by area ratio, and further, a nitrided layer is provided at least to the contact surface to be brought into contact with a material to be worked, and the hardness in a position at a depth of 25μm from the surface of the nitrided layer is regulated to >=1100 HV. Further, V, Nb, N, Co, and Al can be added to the composition of the base material, if necessary.
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