Effect of heat preservation cover on solidification quality in large round bloom

Installing heat preservation covers in the air-cooling zone during continuous casting will affect the solidification quality of large blooms. In this study, a multi-stage anti-radiation heat preservation cover model was developed for heat transfer, and stress coupling calculations based on a vertical continuous casting process of a large round 600 mm diameter bloom. The accuracy of the model was verified by comparing the calculated surface temperature of the bloom against industry-standard surface temperature measurements. Results demonstrate that after applying heat preservation covers with the strongest insulation effect, the surface temperature of the bloom at 14 m from the meniscus increases by 19.42%, and the central porosity area decreases by 23.79%. Furthermore, the maximum stress at the point 43 mm from the centre of the bloom within the ZDT-LIT range decreased by 2.032 MPa. This study elucidates the mechanism underlying the effect of heat preservation covers on the formation of shrinkage and central cracks in the blooms, thereby providing theoretical support for the rational application of heat preservation covers in the vertical continuous casting process of large round blooms.