含钛铁素体不锈钢精炼过程钛合金化工艺研究

Study on titanium alloying technology during the refining of ferritic stainless steel containing titanium

结合含钛铁素体不锈钢工厂试验和热力学计算,研究在VOD还原期、LF精炼前期、LF精炼后期等阶段进行钛合金化时钛的收得率及对钢水质量的影响。结果表明,越靠近精炼结束,钛的收得率越高。VOD还原期进行钛合金化,409L钢的钛收得率为62.7%;在LF精炼后期进行钛合金化,收得率为76%。同时,钛合金化对钢中全氧含量和钢水可浇性也有影响。越靠近精炼结束,钢中全氧含量越高,浇铸过程塞棒位置上涨比例越高。分析表明,采用控制K-OBM-S出钢下渣量、渣中弱氧化物(Cr_(2)O_(3)+MnO+TFe)含量、VOD吹氧量,适当提高钢中铝含量等工艺措施,可以降低钢水氧化性和提高钛收得率。选择在LF精炼前期进行钛合金化,可以降低钢中全氧含量,改善钢水可浇性。

Based on the plant trials and thermodynamic calculation,the titanium alloying of ferritic stainless steel containing titanium during the reduction process of VOD,the early stage of LF and the late stage of LF and its influence on the quality of molten steel were investigated.The results showed that the closer the time of titanium alloying is to the end of refining,the higher the titanium yield was.The titanium yield of 409 L steel was 62.7%after VOD reduction,while the yield of titanium alloy was 76%at the later stage of LF refining.The total oxygen content and the pouring property of steel were also affected by the titanium alloying.The closer it was to the end of refining,the higher the total oxygen content in the steel was and the higher the increase ratio of the plunger position in the casting process was.The oxidizability of molten steel could be reduced and the yield of titanium could be increased by controlling the slag amount from K-OBM-S,weak oxide(Cr_(2)O_(3)+MnO+TFe)content in the slag,VOD oxygen blowing and increasing the total aluminum mass fraction in the steel.The mass fraction of total oxygen in molten steel could be reduced and the pouring property of steel was improved when titanium alloying in the early stage of LF refining.