| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing steel which is excellent in rolling fatigue life and is used for machine parts, by controlling a composition of oxide non-metallic inclusions at a melting step in steelmaking process. SOLUTION: The production method of the steel for machine structure comprises the steps of: refining molten steel, which has been produced in an arc melting furnace or a converter, in a ladle refining furnace; degassing the same and; casting the same to produce an ingot. The obtained steel used for the machine parts has a surface hardness of≥58 HRC and comprises, by mass,≤20 ppm O and <0.010% Al. In the step of refining the molten steel, the molten steel is deoxidized by a Si-containing deoxidizer other than Al and, as soon as the oxygen content in the molten steel reaches≤30 ppm, is further deoxidized by a deoxidizer containing Al in an amount that yields an Al content in the molten steel of <0.010%. COPYRIGHT: (C)2009,JPO&INPIT
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