SPHC低成本精炼渣系研究
Study on Low Cost Refining Slag System of SPHC

为了解决SPHC钢种在精炼脱硫困难和浇注絮流问题，研究适合提高该钢种脱硫率和减少夹杂问题，通过FactSage热力学软件计算LF精炼炉渣的MgO、碱度(R)、钙铝比(ω(CaO)/ω(Al₂O₃))对精炼炉渣的熔点、脱硫能力和去除Al₂O₃夹杂物的影响，得到了SPHC钢种理论精炼炉渣目标成分为：ω(CaO) = 50%~54%，ω(Al₂O₃) = 30%~34%，ω(SiO₂) = 12%~17%，ω(MgO) = 4%~7%。通过SPHC钢种在精炼现场试验，达到目标炉渣成分后，钢水中的w(TO)能够稳定控制在25 × 10^？6以下，w(S)含量能够控制在140 × 10^？6以下，连铸的连拉炉数突破了40炉。
In order to solve the problems of difficult refining and desulfurization and pouring flocculent flow of SPHC steel, the research was conducted to improve the desulfurization rate of this steel and reduce the inclusion problem. The effects of MgO, basicity (R), and calcium-aluminum ratio (ω(CaO)/ω(Al₂O₃)) of LF refining slag on the melting point, desulfurization ability and removal of Al₂O₃ inclusions of the refining slag were calculated by using FactSage thermodynamic software. The target composition of theoretical refining slag for SPHC steel grades is obtained as follows: ω(CaO) = 50%~54%, ω(Al₂O₃) = 30%~34%, ω(SiO₂) = 12%~17%, ω(MgO) = 4%~7%. Through on-site tests of SPHC steel grades, after reaching the target slag composition, the w(T₀) in the molten steel can be stably controlled below 25 × 10^？6, the w(S) content can be controlled below 140 × 10^？6, and the number of continuous casting and drawing furnaces has exceeded 40.