FIRE-RESISTANT MATERIAL FOR GASING RARE EARTH-CONTAINING ALLOYS AND METHOD FOR CASTING RARE-ALLOY ALLOYS.

摘要

Rare-earth alloy is cast into a sheet (6) or the like by using a tundish (3, 13). The refractory material of the tundish used for casting does not necessitate preheating for improving the flowability of the melt (2). The refractory material used essentially consists of 70 wt% or more of Al 2 O 3 and 30 wt% or less of SiO 2 , or 70 wt% or more of ZrO 2 and 30 wt% or less of one or more of Y 2 O 3 , Ce 2 O 3 , CaO, MgO, Al 2 O 3 , TiO 2 and SiO 2 . The refractory material has 1g/cm 3 or less of bulk density, has 0.5 kcal/(mh°C) or less of thermal conductivity in the temperature range of from 1200 to 1400°C, and has 0.5 wt% or less of ratio of ignition weight-loss under the heating condition of 1400°C for 1 hour.