| 摘要 |
PURPOSE:To obtain a steel material with superior cold workability by adding a specified amount of O to specified amounts of C, Si, Mn, P and S as essential components and by carrying out semihot forging at a specified temp. CONSTITUTION:A steel is provided with a composition prepd. by adding <20ppm O to 0.15-1.2wt% C, 0.01-0.15% Si, <2% Mn, <0.03% P and <0.03% S as essential components. The steel is subjected to semihot forging at 400-900 deg.C. To said composition may be added 0.005-0.03% N, <0.2% Al, Nb, Ti and Zr, <0.4% >=2 kinds among Al, Nb, Ti and Zr, or >0.01% in total of >=1 kind among <0.1% Pb, <0.12% Bi and <0.03% Te. |
