（1. Steelmaking Plant, Tangshan Heavy Plate Co., Ltd., Tangshan 063000, Hebei, China 2. Tangshan Branch, Hebei Iron and Steel Company Limited, Tangshan 063000, Hebei, China 3. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China 4. Technology and Research Institute, HBIS Group, Shijiazhuang 050023, Hebei, China）
Abstract：To improve the casting conditions and slab quality of ship plate steel in Tangshan Medium Plate Plant, the field applied mold flux A was modified into mold flux B. Based on the equilibrium phase calculation, the structures of the slag films formed in the mold for mold flux A and B were observed by optical microscope to study the influence mechanism of slag film structure on the lubrication and heat transfer. It can be found that the crystallization temperature and crystallization rate of mold flux A were higher, the main crystallization mineral was melilite with high thermal conductivity, and there were porosities unevenly distributed in the slag film. All these characteristics led to the fast and uneven heat transfer from strand shell to mold and deteriorate the slab lubrication, which resulted in sticking breakout and slab cracks, thus the qualification rate of rolled products was only 98.73%. However, for mold flux B, the crystallization temperature and crystallization rate were relatively decreased, the structure of slag film was obvious layered with appropriate glass layer, and there was moderate cuspidine with low thermal conductivity and a small amount of porosities. These characteristics were in favor of the uniform heat transfer and lubrication between strand shell and mold, which was beneficial to avoiding sticking breakout and reducing slab cracks, thus the qualification rate of rolled products was improved to 99.65%.
刘志远，霍俊梅，王重君，王谦，李双江，刘晓娟. 唐钢中厚板厂连铸保护渣结晶器渣膜矿相分析[J]. 中国冶金, 2017, 27(12): 22-27.
LIU Zhi- yuan,HUO Jun- mei,WANG Chong- jun,WANG Qian,LI Shuang- jiang,LIU Xiao- juan. Crystallization mineral of mold fluxes used in Tangsteel Medium Plate Plant. China Metallurgy, 2017, 27(12): 22-27.
2017, Vol. 27 
