The effects of smelting process and alloying elements on the nitrogen content of cast steel were investigated. It was suggested that the nitrogen content is determined by both smelting process and alloying element content of the steel. The emission of nitrogen gas lessened when the nitride ferrochrome alloy exsited in granular form and in the size of 2 mm to 4 mm during smelting process. With the increase in cooling rate during high temperature phase transformation,the emission of nitrogen gas lessened,so the nitrogen content of cast steel increased. With the decrease in stirring and smelting time,the nitrogen content increased too. The coefficients of interaction between alloying elements such as Cr, Ni, Mn and nitrogen were analyzed in cast steel. A predictive model about nitrogen content was established for the cast high nitrogen Mn-Cr austenitic stainless steel under normal atmosphere state,i.e., (the mass fraction of Mn was 11.8% to 20.7%, that of Cr was 16.5% to 27.5%, and that of C was equal to or less than 0.330%; the melting temperature was from 1 550 ℃ to 1 600 ℃ for atmospheric melting). The predicted results of nitrogen content were in good agreement with the measured values.%通过高频感应炉冶炼试验研究了冶炼工艺、合金元素对铸钢中氮含量的影响.结果表明,冶炼工艺和合金元素含量对铸钢中氮含量影响较大.氮化铬铁合金呈颗粒状且尺寸为2~4 mm时,氮气溢出量小;增加高温相变区冷却速率可减小氮气逸出,增加铸钢中氮含量;减少搅拌和熔炼时间可增加铸钢中氮含量.通过修正合金元素对铸钢中氮的相互作用系数,建立了常压熔炼Mn-Cr系高氮奥氏体不锈钢的氮含量预测模型 (wMn=11.8% ~20.7%,wCr=16.5% ~27.5%,wC≤0.330%;常压熔炼,熔炼温度为1550~1600 ℃),氮含量的预测结果与实测值吻合较好.
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