| 摘要 |
PURPOSE:To improve the durability of refractories by forming the parts where nozzles for continuous casting come into contact with the meniscus part of molten metal of triple structure refractories consisting of spalling resistance refractory layers on the inside and outside walls of the nozzle and a corrosion resistant refractory layer in their middle part. CONSTITUTION:The parts (slag line parts) where the long nozzle and immersion nozzle to be used for continuous casting of the molten metal come into contact with the meniscus part of the molten metal are constituted of the triple structure refractories formed of the spalling resistant refractory layers 1, 3 on the inside and outside walls of the nozzles and the corrosion resistant refractory layer 2 in their middle part. The spalling resistant refractory layers l, 3 are formed of the alumina-graphite-based refractories or zirconia-graphite refractories contg. 20 to 30wt.% flake graphite and the corrosion resistant refractory layer 2 is formed of alumina-graphite-based refractories, etc., contg. 1 to 15wt.% flake graphite indicating an erosion index of <=80 when the erosion index of the refractories constituting the spalling resistant refractory layers 1, 3 is defined as 100. As a result, the nozzle for continuous casting improved in the durability is obtd. |
