| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a carbon steel having its structure controlled, by heating a carbon steel at 900 to 1,200°C, and then, hot-working it at 500 to 700°C, and to provide the carbon steel having the structure controlled so that a ferrite band can be hardly formed. SOLUTION: The method for manufacturing the carbon steel having its structure controlled includes heating the carbon steel at 900 to 1,200°C and then hot-working it at 500 to 700°C. The carbon steel includes, by mass%, 0.4 to 2.0% C, 50 to 200 ppm N, and further at least one element of 0.1 to 0.5% V, 0.01 to 0.1% Ti, 0.01 to 0.05% Al and 0.01 to 0.08% Nb. In the carbon steel having the structure controlled, the ratio of the ferrite band is 5% or less. COPYRIGHT: (C)2008,JPO&INPIT
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