WEIR FOR TUNDISH

PURPOSE:To execute the rectification and at the same time the cleanliness of molten steel by forming at least one of refractory-made weir having plural penetrated holes arranged in a tundish by the refractory containing of the specific weight ratio of calcium oxide and at least one of magnesium oxide and aluminum oxide. CONSTITUTION:The molten steel in the tundish 1 is passed through the plural penetrated hole 3 arranged in the each vertical weir 2, and rectified at the time of pouring into a mold through a nozzle 4 at the bottom wall. At the same time, aluminum oxide in the molten steel is floated up on the molten steel surface, by a reaction with the refractory, forming the penetrated hole 3 or formation of the eutectic composition, caused to form to the low melting compound and mixture. Then, in case of =2,200 deg.C melting point in CaO-MgO-Al2O3 ternary system phase diagram, the refractory is easily eroded by bringing into contact with the molten steel and so aluminum oxide in the molten steel can not be removed for a long period.