高碳钢中氧化物夹杂形成的热力学计算及其在生产中的应用

采用热力学方法对高碳钢中夹杂物形成过程进行理论计算。结果表明:为控制夹杂物成分,应将钢液中的氧活度控制在0.002%～0.004%,酸溶铝的质量分数控制在0.0001%～0.0006%。根据理论计算结果设计控制高碳钢中夹杂物成分的生产工艺。在高碳钢转炉炉后采用弱脱氧工艺,并通过控制精炼过程炉渣成分来控制钢液的酸溶铝质量分数和氧活度,进而对夹杂物的成分进行控制。实际控制结果表明,理论计算和生产实际符合良好,最终夹杂物成分可达到控制目标:w(CaO)/w(SiO2)在0.5～1.0,夹杂物中Al2O3的质量分数为15%～25%。

Thermodynamics calculation of inclusion formation in high carbon steel and its industrial application

Adopting thermodynamics method to calculate the inclusion formation in high carbon steel in theory. The result indicates that oxygen activity in molten steel should be controlled from 0. 002% to 0. 004%, the mass fraction of acid-soluble aluminium in molten steel should be controlled from 0. 000 1% to 0. 000 6% in order to control inclusion components. Production process to control inclusion component in high carbon steel is designed according to theory calculation result. The inclusion composition is controlled by adopting weak deoxidation process behind high carbon steel converter, controlling acid-soluble aluminium mass fraction and oxygen activity in mohen steel through controlling refining slag component. Practical control result indicates that the theory calculation is in accordance with production practice well, final inclusion composition reaches goal composition： the ratio of CaO and SiO2 mass fraction is from 0.5 to 1.0, the Al2O3 mass fraction in inclusion is from 15% to 25%.