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 TiO

2

. 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 decr

easing 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.