| 摘要 |
PURPOSE:To improve nozzle life by constituting the refractory composition of the powder line part of nozzle with the prescribed weight % of ZrO2, SiO2, C. CONSTITUTION:The erosion of immersed nozzle for continuous casting of steel is not caused by the phenomenon, in which ZrO2 and C is simply melted into powder, and is caused by the phenomenon, in which at beginning ZrO2 and part of C is reacted to be gasified, making the refractory composition porous. Therefore, the powder line part is constituted of the refractory having a composition consisting of, by weight, except industrially inevitable impurities, 60-95% ZrO2, 5%-40% SiO2, <=5% C. By this method, various non-routine works at starting and completing of casting are eliminated, the immersed nozzle effective in operational aspect is obtained. |
