CYLINDRICAL CONTINUOUS CASTING MOLD MADE OF COPPER OR COPPER ALLOY AND PRODUCTION OF CRUCIBLE FOR MELTING BY WELDING

摘要

PURPOSE:To prevent the strength deterioration and deformation of a base metal and to form a defect-free weld zone by using the base metal limited in the content of a hydrogen component and oxygen component to a specific value or below, pressing a backing strip made of copper or copper alloy to the rear of the butt weld zone and subjecting the weld zone to electron beam welding. CONSTITUTION:The base metal limited to =5ppm hydrogen component content and =100ppm oxygen component content among the components incorporated into the copper or copper alloy material which is the base metal for welding is used and is subjected to electron beam welding. The backing strip made of the copper or copper alloy is therefore pressed to the rear of the butt weld zone and said zone is welded. The base metal made of the copper or copper alloy has intrinsically a low dissipation rate of heat and therefore the weld zone and the heat affected zone around the same are eventually quickly cooled so that these zones receive, on the contrary, the effect similar to the effect obtd. by a soln. heat treatment without being subjected to annealing and softening. The blowhole defects, etc. generated in the weld zone are decreased by limiting the content of the hydrogen and oxygen components in the base metal.