Crystallization and heat transfer of CaO–SiO2-based slag for high-Mn–high-Al steel
Jie Yang<sup>1</sup>, Deng‑fu Chen<sup>1</sup>, Miao‑yong Zhu<sup>2</sup>
1 College of Material Science and Engineering, Chongqing University, Chongqing 400044, China; 2 School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
Crystallization and heat transfer of CaO–SiO2-based slag for high-Mn–high-Al steel
Jie Yang<sup>1</sup>, Deng‑fu Chen<sup>1</sup>, Miao‑yong Zhu<sup>2</sup>
1 College of Material Science and Engineering, Chongqing University, Chongqing 400044, China; 2 School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
摘要 The crystallization and heat transfer of CaO–SiO<sub>2</sub>-based slag for high-Mn–high-Al steel have been investigatedcoupling composition evolution with heat transfer and non-isothermal tests. It was found that the concentrations of Al<sub>2</sub>O<sub>3</sub> and MnO in the slag were determinedthe relative contents of Al and Mn in molten steel. Crystallization temperature of the slag rose with the increase in Al<sub>2</sub>O<sub>3</sub> content first and then fell due to the coupled effects of basicity and Al<sub>2</sub>O<sub>3</sub>, and a small amount of MnO cannot change this trend. High viscosity of slags led to less obvious characterizations of crystallization. The crystalline phase analysis suggested that MnO accumulation suppressed the formation of fluorite crystals. As the Al<sub>2</sub>O<sub>3</sub> content increased, the precipitation of cuspidine was replacedthe blocky gehlenite crystals, while the number and the size of nepheline and fluorite crystals both increased. According to the thickness and the crystallization structure of slags, the heat flux in the slag film first decreased and then increased with higher Al<sub>2</sub>O<sub>3</sub> accumulation. Then, a new type of CaO–SiO<sub>2</sub>-based mold slag with high basicity was applied in plant trial, and the change in composition and properties of mold slag was studied.
Abstract:The crystallization and heat transfer of CaO–SiO<sub>2</sub>-based slag for high-Mn–high-Al steel have been investigatedcoupling composition evolution with heat transfer and non-isothermal tests. It was found that the concentrations of Al<sub>2</sub>O<sub>3</sub> and MnO in the slag were determinedthe relative contents of Al and Mn in molten steel. Crystallization temperature of the slag rose with the increase in Al<sub>2</sub>O<sub>3</sub> content first and then fell due to the coupled effects of basicity and Al<sub>2</sub>O<sub>3</sub>, and a small amount of MnO cannot change this trend. High viscosity of slags led to less obvious characterizations of crystallization. The crystalline phase analysis suggested that MnO accumulation suppressed the formation of fluorite crystals. As the Al<sub>2</sub>O<sub>3</sub> content increased, the precipitation of cuspidine was replacedthe blocky gehlenite crystals, while the number and the size of nepheline and fluorite crystals both increased. According to the thickness and the crystallization structure of slags, the heat flux in the slag film first decreased and then increased with higher Al<sub>2</sub>O<sub>3</sub> accumulation. Then, a new type of CaO–SiO<sub>2</sub>-based mold slag with high basicity was applied in plant trial, and the change in composition and properties of mold slag was studied.
Jie Yang,Deng‑fu Chen,Miao‑yong Zhu. Crystallization and heat transfer of CaO–SiO2-based slag for high-Mn–high-Al steel[J]. Journal of Iron and Steel Research International, 2020, 27(7): 788-795.