Numerical Simulation and Application of Tundish Cover Argon Blowing for a Two-Strand Slab Continuous Casting Machine

Abstract

During continuous casting, argon blowing from tundish cover (ABTC) can greatly prevent the flow of the remaining air and decrease the reoxidation of molten steel in tundish. In the current study, a numerical model based on a tundish of a two-strand slab continuous casting machine was established to investigate the feasibility and evaluate the protective casting effect of the ABTC process. The influence of operation parameters, including sealing schemes of tundish cover holes and the argon flow rate of the remaining oxygen content, were studied in tundish. Then, industrial trials based on the operation parameters from the numerical model were carried out to evaluate the protective effect of ABTC. The results indicate that the ABTC process has a great protective effect in avoiding increasing levels of nitrogen and losing titanium and aluminum. With the ABTC process applied, the average increment of nitrogen (△w[N]) in steel from the end of RH to tundish decreases by 90% from 10 × 10−6 to 1 × 10−6, the average loss of titanium (△w[Ti]) by 12.7% from 63 × 10−6 to 55 × 10−6, and the amount of aluminum (△w[Al]) decreases by 7.1% from 70 × 10−6 to 55 × 10−6. The injecting hole and baking holes should be sealed during the period of empty tundish to efficiently discharge the air. In order to ensure that the oxygen volume fraction in tundish is less than 1%, the argon flow rate should be ≥220 Nm3/h during the period of empty tundish and ≥80 Nm3/h during the period of normal casting.