防止含钛焊丝钢GF50-G水口结瘤的生产实践

含钛焊丝钢GF50-G（/%:0.08C,0.83Si,1.55Mn,0.014P,0.012S,0.19Ti）生产流程为80 t顶底复吹转炉-LF-160 mm×160mm方坯连铸,在浇注过程中经常出现水口结瘤现象。扫描电镜和能谱仪对水口结瘤物的分析得出,结瘤物主要物相为TiO₂。水口结瘤的热力学计算表明,为避免钛脱氧产物被Al]还原形成铝钛系夹杂物,应控制Als]在0.008%以下。根据生产实践,将中间包钢水温度从1542℃提高至1 550℃控制Alt]≤0.010%、加钛铁前使O]≤15×10^-6、减少钢水的二次氧化能够防止水口结瘤、连浇炉次从3～4炉提高到8～10炉。

Production Practice of Preventing Nozzle Clogging for Casting Ti-Bearing Welding Wire Steel GF50-G

The production flowsheet of Ti-bearing welding wire steel GF50-G (/% : 0. 08C, 0. 83Si, 1.55Mn, 0. 014P, 0. 012S, 0. 19Ti) is 80 t top and bottom combined blowing converter-LF-160 mm x 160 mm billet casting, and the phenomenon of nozzle clogging often occurs in casting process. It is obtained by analysis of SEM and EDS on nozzle clogging deposit that the main phase in deposit is TiO₂. The thermodynamic calculation of nozzle clogging deposit shows that the Al content in liquid steel- Als] should be controlled less than 0. 008% in order to avoid Ti-deoxidized products being reduced by Al] and forming aluminium-titanium inclusions. Based on production practice with increasing temperature of liquid steel in tundish from 1 542 °C  to 1 550 °C , controlling Alt] ≤ 0. 010% , O] ≤ 15 x 10^-6 before adding ferrotitanium and decreasing reoxidation of liquid steel the nozzle clogging could be prevented, and the continuous casting heats may increase from 3 ~4 heats to 8 ~ 10 heats.