Study on Controlling Nitrogen of Wheel Steel Produced by BOF-LF-VD-CC Process

According to conventional technological conditions of producing wheel steel at Ma'anshan Iron and Steel,the Variation of nitrogen content in the liquid steel was determined through industrial experiment.The results show that the main procedure of the nitrogen absorption in the LF→VD→CC process includes the LF, from ladle to tundish and from tundish to mould,the nitrogen absorption in the LF process is higher than that in the others,the average nitrogen absorption is about 28×10^-6,and the maximum value is about 50×10^-6.The prevention measures of nitrogen absorption are discussed,and the effect of denirtiding in VD process is significant.The average denitriding rate is about 30% and average denitriding value is 21×10^-6.The main factors affecting the denitriding in VD process and the optimum technological parameters in VD process are analyzed.