Continuous Casting Soft Reduction Control of Macro-/Semimacro Synergistic Homogeneity of Bloom and Rod for CF53 Camshaft Steel

The cross wedge rolling process exposes the camshaft center to complex alternating shear and tensile stresses, which require exceptionally high homogeneity in the steel. This study investigates the macro/semimacro segregation and mechanical properties of bloom and rod for CF53 camshaft steel. Based on the findings, the study proposes a mechanism and strategy for controlling the macroscopic and semimacroscopic homogeneity of CF53 camshaft through soft reduction. The results indicate that applying a 7–10 mm reduction when the center solid fraction is 0.1–1.0 can promote the flow of liquid steel at the solidification end, reduce the size of the equiaxed crystals, significantly decrease the central segregation and the carbon range on transverse cross sections, and considerably reduce the size and number and solutes enrichment of semimacroscopic spot segregations in the blooms. Correspondingly, the central segregation and banded defects in the rods improve. The plasticity and toughness in the radial direction of the rods are enhanced. This demonstrates that SR can synergistically regulate the macro/semimacro homogeneity of camshaft steel blooms and rods, providing high-quality materials for subsequent processing and improving the competitiveness of camshaft products.