METHOD FOR MANUFACTURING CAST MATERIAL OF Mg ALLOY, AND CAST MATERIAL OF Mg ALLOY, AS WELL AS WROUGHT PRODUCT AND MOLDED ARTICLE

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a cast material of Mg alloy in which the hydrogen concentration of the cast material of the Mg alloy can be reduced by preventing absorption of hydrogen to a molten metal of the Mg alloy.SOLUTION: A cast material is manufactured by dissolving an Mg alloy in a fusion furnace, then transferring a molten metal to a holding furnace, and supplying the molten metal from the holding furnace to a continuous caster through a sprue. Then, a molten metal holding time before supplying the molten metal to the caster after dissolving the Mg alloy in the fusion furnace is made to be 60,000 seconds or less. Accordingly, the absorption of hydrogen to the molten metal can be effectively suppressed, and the hydrogen concentration of the cast material can be suppressed to 25 mass ppm or less, and thereby internal defects such as air bubbles due to hydrogen can be suppressed from occurring in the cast material.