| 摘要 |
PURPOSE:To provide a CaO base nozzle suitable to a nozzle for discharging molten metal of various kinds of high activated and high m.p. metals or the alloys, etc. CONSTITUTION:The CaO base nozzle 1 composed of calcined body of CaO base refractory containing >=40wt.% CaO and minus sieve of 300mum grain diameter in the used raw material at the tip part, is manufactured. The CaO base refractory containing >=40wt.% CaO, is scarcely contaminated even to the molten high activated metal or alloy, and damaged in a little with the molten metal. When a deoxidizing element is contained in the molten metal, the refining action is developed, too. As the grain diameter in the used raw material at the tip part is made to the minus sieve of 300mum, bounding strength among the grains at the tip part is high and shrinkage deformation is little. Therefore, breakage of the discharging hole 2 at the tip part of the nozzle is prevented and further, the dimensional accuracy is improved. |
