| 摘要 |
Disclosed is a hot-working tool steel having improved toughness and high-temperature strength. Also disclosed is a method for producing the hot-working tool steel. The hot-working tool steel comprises the following components (by mass): C: 0.34-0.40%, Si: 0.3-0.5%, Mn: 0.45-0.75%, Ni: 0-0.5% (exclusive), Cr: 4.9-5.5%, (Mo+1/2W): 2.5-2.9% (provided that Mo and W are contained singly or in combination), and V: 0.5-0.7%, with the remainder being Fe and unavoidable impurities. Preferably, the cross-sectional structure of the hot-working tool steel upon quenching contains a granular structure and an acicular structure, wherein the granular structure (A%) accounts for 45 area% or less, the acicular structure (B%) accounts for 40 area% or less, and the remaining austenite (C%) accounts for 5 to 20 volume%.; Also disclosed is a method for producing a hot-working tool steel, which comprises tempering the above-mentioned hot-working tool steel so that a value X determined by the following relational expression between a tempered hardness (HRC) and the percentages of the tissues becomes 40 or greater. X = - 0.36 × HRC - 1.47 × A % - 1.67 × B % + 6.55 × C % + 72.91 |
