| 摘要 |
PROBLEM TO BE SOLVED: To provide a billet for cold forging which is formed by the continuous forming of cold forging, good in hardenability and moreover free from the need of a heat treating stage in the process of the continuous forming. SOLUTION: The billet for iron steel has a composition consisting of, by weight, 0.46 to 0.48% C, <=0.14% Si, 0.55 to 0.65% Mn, <=0.015% P, <=0.015% S, <=0.15% Cu, <=0.20% Ni and <=0.35% Cr and is manufactured by being subjected to spheroidizing annealing treatment and drawing and thereafter subjected to spheroidizing annealing treatment.
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