Numerical Investigation of the Cleaning Flame Jet and Formation of the Molten Pool in the Corner Scarfing Process of the Casting Slab

Abstract

The corner defects in the casting slab greatly influence the product quality. These defects may extend during the heating and rolling process and even result in the discarding of the rolled plate as scrap. A corner cleaning equipment based on the scarfing machine is proposed to eliminate the defects in slab corners for producing high-quality steel. Unlike the flat surface scarfing process, the flame jet and the shape of the molten pool have an essential impact on the effectiveness of the flame cleaning in the corner of the casting slab. A three-dimensional fully coupled model for the flame cleaning nozzle is developed to simulate the flow pattern of the flame jet, Oxygen concentration distribution, and temperature field in the corner of the slab. The simulated flame jet flow field and temperature results agreed well with the factory trial results. Additionally, a three-dimensional thermal model for simulation of the molten pool formed by flame cleaning in the corner of the casting slab has also been developed. For the sake of simplicity, the 2D elliptic and 3D Gauss heat source models are used to simulate the flame heating on the upper and right surfaces of the slab corner and the reaction heating between oxygen and heated iron along the corner, respectively. The simulation results show that the length is 58.1 mm and 57.9 mm on both sides and the corner melting depth is 29.9 mm. The error is 7.04%. The numerical simulation results showed good agreement with the factory trial results, indicating that the proposed models of the flame jet and the heat sources analysis are feasible to study the flame cleaning process of the slab corner, it provides the scientific theoretical basis for the design and practical application of corner scarfing machine.