Being the production methodological null aging hardenable steel of the aging

摘要

C: 0.025~0.25%, Si: 0.05~0.50%, Mn: 0.50~1.8%, P ≦ 0.05%, S ≦ 0.10%, Cr: 0.05~0.6%, Al ≦ 0.06%, Ti: 0.005~0.20%, V: contains 0.012% N ≦ and 0.10 to 0.60%, the balance consisting of impurities and Fe, has a chemical composition that satisfies the [N / Ti ≦ 0.60] and [C / V ≧ 0.20], the area ratio of bainite But age-hardening of steel having an organization of more than 50%, is very useful as a material for automobile machine parts, industrial machinery, such as construction machinery. Age-hardening of steels described above, may include one or more of specific amounts of Cu, Ni, Mo, Nb, B, and Bi and Ca. According to the production method of the present invention, it is possible to manufacture machine parts that established a product shape by performing cutting in the hardness of the steel is low, a desired strength can be cured by aging treatment thereafter.