材料期刊网

用扫描电镜（SEM/EDS）分析了高钛焊丝钢连铸水口结瘤物和钢液中夹杂物的形貌和组成，结果表明：结瘤物的主要组成是TiOx和凝钢；精炼结束后钢液中的夹杂物主要是MnO-Al2O3-SiO2-TiOx、MgO-Al2O3-TiOx和TiOx类夹杂物；钢液中大量的高熔点含钛夹杂物是导致水口结瘤的主要原因。对钢液中的Al-Ti-O平衡和钢渣间的平衡进行了热力学计算，结果表明：当w([Al])/w([Ti])＜0.15时，氧优先与钛结合，反之优先与铝结合；当钢包渣中的w((FeO))＜0.05%、w((SiO2))＜15%时，可避免钛被炉渣氧化。通过对冶炼工艺参数和操作过程的优化，钢液中TiOx的质量分数从0.0024%降低到0.0010%以下，钢液的可浇性得到明显改善。

Severe SEN (Submerged Entry Nozzle) clogging issue occurred in the continuous casting process of high Ti-bearing welding wire steel. The chemical composition of clogs was characterized using SEM/EDS. The results indicate that the major constituent phases are TiOx and solidified steel. The morphology and chemical composition of inclusions in liquid steel were analyzed by SEM/EDS. The results show the inclusion types at LF end are MnO-Al2O3-SiO2-TiOx , MgO-Al2O3-TiOx and TiOx . The Ti-bearing inclusions with high melting point in liquid steel are the dominant reason to SEN clogging. Al-Ti-O equilibrium in liquid steel and steel-slag equilibrium were calculated by thermodynamic method. The results show oxygen is preferred to combine with Ti to form Ti2O3 when w([Al])/w([Ti])<0.15 ,otherwise,oxygen is preferred to combine with Al;the titanium would not be oxidized by slag when w((FeO))<0.05%,w((SiO2))<15%in ladle slag. TiOx inclusion content in liquid steel is reduced from 0.002 4%to below 0.001%after the process parameters and operation are optimized;hence,the castability of liquid steel is improved significantly.