JPS6427743A - Mold for continuously casting metal - Google Patents

Abstract

PURPOSE:To prevent damage of a ceramic caused by thermal shock crack by joining a material having high heat resistance at outside of the ceramic so as to apply uniform compressed stress from circular direction of the ceramic in a mold lining the ceramic. CONSTITUTION:The ceramic material 2 lined in the water cooled copper mold 1 is inserted to molten metal 6 at one end thereof and the outer surface at the other end thereof is brought into contact with a copper plate 10 and cooled and at the time of starting casting, the ceramic material 2 is rapidly heated by flow of the molten metal and damage by the thermal shock. In order to prevent the above damage, the outside material 3 having high heat resistance is joined on the outer circumference of the ceramic material 2 by shrinkage fitting or casting. By this method, as the compressed stress is beforehand applied to the ceramic material 2, and expansion caused by heating is reduced and development of the crack can be reduced. Further, even if crack is developed, the crack does not open to outside, and breakout, etc., caused by holding with penetrated solidification of molten metal is not developed. Further, as the good thermal conductivity between the joined surfaces is obtd. by this joining, thickness of the ceramic material 2 can be made thicker or the temp. can be made lower corresponding to the improving quantity, and the crack can be reduced.