Abstract: The element content， phase composition and interface reaction of nozzle clogging for titanium-bearing welding wire steel SJ-60 during continuous casting were analyzed by means of XRF， XRD and SEM. It is found that the interface of the nozzle is rough and porous due to decarburization reaction， which causes nozzle to be easily invaded by high melting point phases. In addition， the calcium treatment and erosion of refractory during the refining process will produce a large amount of CaTiO₃ and MgAl₂O₄ in the molten steel， and the deposition of both at the interface of the nozzle is the main cause of nozzle clogging. The practice has shown that replacing ordinary ferrosilicon with low titanium and low aluminum ferrosilicon can reduce the aluminum content in steel from 0.008 0%~0.009 5% to 0.005 0%~0.006 5%， which is beneficial for reducing the content of Al₂O₃ inclusions in steel. Cancelling the refining calcium treatment can reduce the calcium content in steel from more than 0.001 4% to less than 0.000 5%， which is beneficial for reducing the content of CaTiO₃ inclusions in steel. Reducing the amount of fluorite from 0.8~1.0 kg/t to 0.3~0.5 kg/t can reduce the erosion of refractory， and the magnesium oxide content in slag is decreased from more than 10% to less than 5%， which is beneficial for reducing the content of MgAl₂O₄ inclusions in steel. Through the above measures， the problem of nozzle clogging caused by CaTiO₃ and MgAl₂O₄ has been effectively solved，and the number of continuous casting heats is increased from 4-5 heats to more than 12 heats.

Key words: Titanium-Bearing Welding Wire Steel, Nozzle Clogging, Calcium Titanate, Spinel, Titanium Nitride

摘要： 针对含钛焊丝钢SJ-60连铸过程中水口结瘤问题，通过XRF、XRD和SEM等手段，分析水口结瘤物的元素含量、物相组成及界面反应。结果发现，水口内壁因脱碳反应而变得粗糙多孔，导致高熔点物相易于侵入；此外，精炼过程喂钙处理和耐材侵蚀，会使钢液生成大量CaTiO₃和MgAl₂O₄，二者在水口内壁沉积是导致水口结瘤的主要原因。实践表明，采用低钛低铝硅铁替代普通硅铁，将钢中w［Al］由0.008 0%~0.009 5%降低至0.005 0%~0.006 5%，有利于减少钢中Al₂O₃夹杂物含量；取消精炼钙处理，将钢中w［Ca］由＞0.001 4%降低至＜0.000 5%，有利于减少钢中CaTiO3夹杂物含量；将萤石用量由0.8~1.0 kg/t降低至0.3~0.5 kg/t，减轻耐材侵蚀，渣中w（MgO）由＞10%降低至＜5%，有利于减少钢中MgAl₂O₄夹杂物含量。通过以上措施，有效解决了CaTiO₃和MgAl₂O₄引起的水口结瘤问题，连浇炉数由4~5炉提高至12炉以上。

关键词: 含钛焊丝钢, 水口结瘤, CaTiO₃, MgAl₂O₄, TiN