To provide tool steel excellent in the antipodal properties of weldability and machinability.
This steel contains, by weight, 0.45 to 0.85% C and 5.0 to 8.5% Cr, in which the deviation of the matrix composition in the quenched structure G is ≤3.3 by the SKD11 standard, and moreover, the amt. of primary carbides observed in the structure after quenching and tempering is ≤3% by area ratio. Concretely, tool steel contg. 0.45 to 0.85% C, 0.1 to 1.2% Si, 0.1 to 1.2% Mn, 5.0 to 8.5% Cr and one or two kinds of Mo and W by (Mo+1/2W): 0.6 to 3.0%, and the balance Fe with inevitable impurities is prepd., and preferably, the content of V is controlled to ≤1.0%, Ni to ≤1.0%, S to ≤0.2% and Ca to ≤100 ppm. The tool steel is subjected to refining and machining to the hardness of ≥55 HRC to form a tool or a die.
ABE YUKIO
TAMURA ISAO
KADA YOSHIHIRO
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