| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel for hot-forging die and the hot-forging die using the steel having excellent high temperature strength and also, excellent nitriding characteristic. SOLUTION: This steel for hot-forging die is composed by mass% of 0.3-0.5% C, <=1.0% Si, <=1.0% Mn, 0.5-1.5% Ni, >0.3 to 3.6% Cr, 2.0-4.0% single of Mo and W or complex of (Mo+1/2W), 0.2-1.5% V, 0.4-0.7% Al and the balance Fe with inevitable impurities and further, composed of <=0.5% Co in addition to the above. Further, in the steel for hot-forging die, N is regulated to <=0.100%, or further, P, S and O being the inevitable impurities are desired to be regulated to <=0.025%, <=0.010% and <=0.005% respectively. Then, this hot-forging die is manufactured by using this steel for hot-forging die and has a nitrided layer.
|
