LAUSR

In order to investigate the inclusion modification process and predict final inclusions after the injection of calcium, based on actual data of injection of calcium and inclusion thermodynamic calculation, a three-dimensional model for calcium treatment in LF refining furnace for pipeline steel was established. The evolution of concentrations and distribution of the modification inclusions in the liquid steel during the injection of calcium were investigated. The results showed that when the length of feeding calcium was 600 m, after about 1000 s, the average calcium equilibrium concentration was 1.86 × 10−5 and the recovery of calcium was 23.2%. The average equilibrium concentration of C3A, C12A7, CA(C stands for CaO and A stands for Al2O3) and CaS, respectively, was 0, 25.7 × 10−6, 3.04 × 10−6 and 13.7 × 10−6. The final modified inclusion was related to the amount of feeding calcium. The equilibrium value of C12A7 and CaS increased with the increase of feeding amount; however for CA, the regularity was opposite.