METHOD OF MANUFACTURING HOLLOW BILLET AND APPARATUS THEREFOR

摘要

This invention provides a method and apparatus for manufacturing hollow billets such that a core is located at a central portion of a molten metal storing portion in a vertical semi-continuous mold, the molten metal is poured into the molten metal storing portion, and casting takes place with the inner diameter of a solidified distal portion of the molten metal being controlled by a distal portion of the core. The invention provides a reliable method for the manufacture of high-quality hollow billets which are free from internal defects.