LF Refining Slag System Optimization and Industrial Testing for 65Mn Steel

• Published in: Teshugang
• Main Authors: Zhang Baozhong, Sun Guomin, Li Zhiwei, Peng Yongsheng, Liu Wanshan, Zhu Shili
• Format: Article
• Language: Chinese
• Published: Editorial Office of Special Steel 2023-08-01
• Subjects: 65Mn Steel; LF; Refining Slag; Total Oxygen; Thermodynamic Calculation
• Online Access: http://www.specialsteeljournal.com/thesisDetails#10.20057/j.1003-8620.2023-00009
• ISSN: 1003-8620

In order to study the LF refining slag system suitable for high cleanliness and high carbon steel， the influence of refining slag alkalinity （<italic>R</italic>），（CaO）/（Al₂O₃） on the melting point of the refined slag was calculated by FactSage thermodynamic software， and the most suitable refining slag composition was obtained. According to the thermodynamically calculated refining slag composition， the calcium-aluminum ratio of the original slag system was reduced， and the optimized slag composition was used for the 65Mn steel industrial test. The results show that the optimized refining slag components mass fraction are CaO 52%-58%， Al₂O₃ 28%-33%， SiO₂ 8%-12%， MgO 5%-7%， <italic>R</italic>=4-6， （CaO）/（Al₂O₃）=1.5-2. Using this slag system for industrial tests， T.［O］ can reach 7×10^-6-13×10^-6 after LF process T.［O］ can reach 6×10^-6-12×10^-6 after RH process. The mass fraction of dissolved oxygen in the basically controllable steel is within 10×10^-6， The Class B thin inclusion grades in the 65Mn steel coil are not more than 1 grade， which meets the requirement of high quality steel.