高钛焊丝用钢的钢液可浇性改善

 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0.002 4%降低到0.001 0%以下，钢液的可浇性得到明显改善。

Castability improvement of high Ti-bearing welding wire steel

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.