Heat transfer characteristics and stress analysis of a new tundish with vacuum chambers

Abstract

Vacuum insulation can improve tundish insulation performance while increasing molten steel temperature. The tundish's heat transfer characteristics and thermal stress changed significantly following vacuum modification. A complete understanding of this process can improve the insulation and safety performance of vacuum tundishes. The heat transfer process and stress distribution of a tundish were investigated in this study using a fluid–structure coupling heat transfer analysis method. The variations in the temperature and stress fields of the tundish before and after vacuum modification were discussed, and the numerical model’s accuracy was validated using industrial experiments. Compared to the traditional tundish, the temperature distribution of the molten steel was more uniform; the outlet temperature of the vacuum tundish increased by 1.38 K, whereas the temperature of the outer wall decreased by 46 K. However, the higher temperature of the steel shell in the vacuum tundish resulted in an increase in thermal stress, which reached a maximum of 301.74 MPa. When high-strength Q345 steel was used as the steel shell material, the thermal stress decreased to 272.44 MPa. The results showed that a vacuum tundish can achieve low-superheat pouring of molten steel, and the thermal stress of the tundish can be improved by material selection.