| 摘要 |
PURPOSE:To lessen the clogging of the nozzle by constituting the nozzle for casting of a compsn. contg. specific ratios of ZrSiO4, ZrO2, CaSi, CaSiF6 and C CONSTITUTION:The nozzle for casting is formed of the compsn. contg. 50 to 80wt.% one or two kinds of ZrSiO4 or ZrO2, 1 to 20wt.% one or two kinds of CaSi or CaSiF6 and 5 to 30wt.% carbon. The CaSi and CaSiF6 are oxidized by the oxygen in the steel to CaO and SiO2, which forms a low melting point of an Al2O3-CaO-SiO2 by reacting with the alumina sticking to the surface layer part of the nozzle. The CaSi and CaSiF6 melt at the casting temp. and, therefore, run off without sticking to the nozzle. The clogging of the nozzle is thus lessened and the safe operation and the productivity are assured. |
