氮的溶解度及预处理过程脱氮的实验研究

Experimental Study on Nitrogen Solubility in Molten Iron and Denitrification during Hot Metal Pretreatment

在实验室1573～1673K条件下对铁水预处理过程进行了脱氮研究。结果表明,铁液中氧、硫和碳含量都在不同程度上影响氮在铁水中的溶解度,并用线形回归方法得到了氮溶解度与碳含量的关系式,预处理过程中初始碳含量对脱氮影响较为明显,在供氧强度相同的条件下,脱氮量随着铁水中碳含量的增加而增加,同时研究发现过程脱碳的同时能有效地脱氮,且脱碳量越大脱氮率越高.终点最低氮含量可达13×10^(-6),脱氮率超过50％,可满足超低氮钢对铁水中氮含量的要求。

Denitrification during hot metal pretreatment is studied under laboratory conditions in the range of 1573 -1673 K. The results show that the oxygen, sulphur and carbon contents can somewhat reduce the nitrogen solubility in molten iron, and the nitrogen solubility is in linear regression relation with the carbon content. The effects of the initial carbon content on denitrification is obvious. At the same intensity for offering oxygen, the amount of removing nitrogen increases with increasing the carbon content in the hot metal. It is also found that effective denitrification takes place during decarbonizing in the pretreatment. The denitrification ratio is improved with the amount of decarbonization increasing. The lowest nitrogen content at the end point reaches to 13×10-6, and the denitrification ratio exceeds about 50%, which can meet the demand of ultra-low nitrogen steels for nitrogen content in molten iron.