Abstract: In this paper, the effect of ladle nozzle on nitrogen addition of molten steel was introduced by the process of 110 t electric furnace→LF refining→VD refining→continuous casting in Jiangsu Yonggang Group Co.,Ltd. By optimizing the inner cavity structure of the long nozzle, the contact surface between the lower nozzle and the long nozzle was increased to improve the sealing performance, and the material was improved. Compared with the original long nozzle, under the same conditions, the nitrogen addition of molten steel decreased from 5.8×10^-6 to less than 1.2×10^-6, and the structure optimization of long nozzle achieved the expected results.

Key words: ladle, long nozzle, structural optimization, nitrogen addition