| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deposition and adhesion of an alumina inclusion on the inside surface of a nozzle and to stably cast by constituting an inside hole surface layer part in contact with molten steel of a compsn. consisting of aggregate consisting of Al2 O3 or essentially consisting of the Al2 O3 and having a specific m.p., silicon carbide and the balance agalmatolite. SOLUTION: The compsn. described above consists of 15 to 60 wt.% aggregate having a m.p. above 1,800 deg.C, 1 to 10 wt.% silicon carbide and the balance agalmatolite. More preferably the agalmatolite is formed by using <=60 wt.% of the total agalmatolite compounding ratio for a grain size of <=250 μm and pyrophyllite (Al2 O3 /4SiO2 /H2 O) as essential components and calcining the mixture at >=800 deg.C to annihilate the water of crystallization. The binder is a thermosetting resin. The inside hole surface layer part 2 of the inside hole 1 of the nozzle 10 for continuous casting where the molten steel flows is formed of refractories having a prescribed chemical component compsn. The portion 3 exclusive of the surface layer part is alumina graphitic and is used as the immersion nozzle for pouring the molten steel from a tundish into a mold. As a result, the closure of the inside hole 1 is prevented. |
