Effect of Dynamic Soft Reduction Range and Amount on Central Segregation in Bloom and the Resulting Microstructure in the Rod of GCr15‐Bearing Steel

Abstract

Composition uniformity is essential to the quality, stability, and fatigue life of bearing materials. In the current study, various calculations and measurement methods are implemented to obtain the high‐temperature physical properties of GCr15‐bearing steel. Combined with a validated transient heat transfer model, two cases with different dynamic soft reduction (DSR) ranges and amounts are designed for industrial trials. The defects, carbon contents, and carbides in the bloom center and the carbon contents and microstructure in the rod center are compared. The results show that the reasonable matching of casting speed and cooling water flux in continuous casting could reduce the total content of enriched carbon at the middle and late stages of solidification. Setting a reasonable DSR range (solid fraction: 0.3–1.0) and applying a heavy DSR amount could effectively improve central segregation in bloom and the resulting microstructure in the rod.