Process for continuously casting light alloy and apparatus for continuously casting light alloy

摘要

An ingot I made of a light alloy is produced using a continuous casting apparatus including a cylindrical water-cooled casting mold which is disposed immediately below a spout having an upward-turned molten metal receiving port and a downward-turned molten metal outlet, and which has an inside radius r₁ larger than an inside radius r₂ of the molten metal outlet, and lubricating oil discharge passages provided below the spout to supply a lubricating oil to between the water-cooled casting mold 13 and a molten metal m brought into contact with the water-cooled casting mold. In this production, a lubricating oil having a vaporization rate of 30% or more at 300° is used, and an annular gas accumulation for spacing the molten metal apart from outlets of the lubricating oil discharge passages is defined below an annular protrusion of the spout by vaporization of the lubricating oil. Thus, it is possible to avoid the generation of a casting skin failure in a light alloy ingot due to the outlets of the lubricating oil discharge passages.