Numerical Simulation of Solidification Structure for YQ450NQR1 Steel Bloom in Continuous Casting Process

Abstract

The solidification structure of continuous casting bloom has a significant impact on quality and performance of final products. In this paper, numerical simulation for a 360mm×450mm YQ450NQR1 steel continuous casting bloom is carried out to study the impact of superheat and secondary cooling water flowrate on solidification structure of the bloom using coupled Cellular Automaton-Finite Element (CA-FE) method. The results show that increase of superheat and secondary cooling water flowrate leads to dendrites growth acceleration and coarsening from bloom surface to the center and decrease in equiaxed grain ratio. When the superheat increases from 10°Cto 40°C, the equiaxed grain ratio drops from 45.6% to 22.3% and the average grain diameter increases from 1.63mm to 1.92mm. When secondary cooling water flowrate increases from 0.35L/kg to 0.65L/kg, the equiaxed grain ratio drops from 37.7% to 23.1% and the average grain diameter increases from 1.68mm to 1.98mm.