| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of high carbon chromium bearing steel having the microstructure with carbide being uniformly diffused therein and excellent rolling fatigue characteristic by efficiently executing the soaking treatment by employing the two-stage heating treatment in order to achieve diffusion extinction by heating huge carbide present attributable to the component segregation of a center area of a cast slab in a short time. SOLUTION: The method for manufacturing high carbon chromium bearing steel comprises a preliminary heating step of charging a cast slab obtained by the casting into a heating apparatus, raising the temperature of a center area of the cast slab to the temperature zone at the solidus temperature to the temperature lower than the solidus temperature by 50°C, and keeping the cast slab in this temperature zone for 1 to 4 hours, and a permanent heating step of raising the temperature of the cast slab by the heating apparatus to 1,200-1,280°C after the preliminary heating step, and keeping the cast slab in this temperature zone for 0.5-4 hours, and the cast slab is subjected to the soaking treatment in the two-stage temperature zone. By performing the treatment in the preliminary heating step, the solidus temperature of the center area of the cast slab after the preliminary heating treatment is preferably raised to≥1,200°C. COPYRIGHT: (C)2009,JPO&INPIT
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