连铸板坯表面裂纹及微观组织优化研究

here is high risk on slab surface quality control since the complicated effects of the continuous slab casting factors. The steel grade A516Gr60N, which applies for pressure vessel in condition of middle&low temperature, with a composition near and out the range of peritectic area, have some occasionally longitudinal surface crack caused by the thin, heterogeneous surface chilly layer and Widmanstatten microstructure. Trails were carried out with the same casting parameters but different mold flux. The results show that there were homogeneity mixed structure with small size ferrite and pearlite, which is benefit for the improvement of thermoplastic of the slab surface material, by applying the mold flux B, which have appropriate chemical composition, melt point and viscosity, it benefit for the heat transfer from inner slab to the mold. The longitudinal crack was optimized after the mold flux B applied and with the same casting parameters as they before.