侧底复吹RH真空精炼脱碳过程研究

Study on Decarburization Process in RH Degasser with Side-Bottom Blowing

基于RH内流场,结合冶金反应热力学及动力学,通过建立数学模型研究了侧底复吹RH真空脱碳过程.数值结果表明计算结果与试验结果符合良好.在总吹气量相同条件下,侧底复吹RH前20 min的脱碳速率高于传统RH的脱碳速率.对于传统RH脱碳,前3 s以熔池内CO本体脱碳为主,3~1 000 s以氩气泡表面脱碳为主;对于侧底复吹RH脱碳,前1 000s以氩气泡表面脱碳为主,并且氩气泡表面脱碳速率约为熔池内CO本体脱碳速率的两倍;提高RH处理后期的脱碳速率可提高超低碳钢生产效率.

Based on the flow field in RH degasser, the metallurgical reaction thermodynamics and kinetics, a mathematical model was developed to investigate the decarburization process in RH degasser with side-bottom blowing. The numerical results indicate that the predicted results agree well with the experimental data. Under the condition of the same blowing gas flow rate, the decarburization rate in the first twenty minutes in Rid with side-bottom blowing is greater than that in traditional RH. For decarburization in traditional RH, the decarburization in the inner site of the vacuum chamber accounts for the majority of the removed carbon in the first three seconds, while the decarburization rate at the surface of argon bubbles accounts for the majority of the removed carbon during three to one thousand seconds. For decarburization in RH with side- bottom blowing, the decarburization rate at the surface of argon bubbles accounts for the majority of the removed carbon in the first one thousand seconds, and decarburization rate at the surface of argon bubbles is as high as about two times of that in the inner site of the vacuum chamber. The production efficiency of ultra low carbon steel can be improved by increasing decarburization rate during final RH treatment.