MANUFACTURING METHOD FOR PIECE OF CAST WHICH HAS FINE SOLIDIFICATION STRUCTURE AND STEEL PRODUCT WHICH IS PROCESSED FROM IT

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method for a piece of a cast with a fine solidification structure which can prevent occurrence of internal defects of a piece of the cast by adding Zr to molten steel of which solidified primary crystal is γ-Fe and producing a large amount of fine ZrO₂, which are utilized as an absorption core of molten steel to make the solidification structure of the piece of the cast finer, and also to provide a steel product which is processed from the piece of the cast.;SOLUTION: The piece of the cast 25, which is provided with the fine solidification structure, is produced by continuous casting after the material containing Zr 14 has been divided into a plurality, added to the molten steel 11 of which solidified primary crystal is γ-Fe and ZrO₂ has been produced in the molten steel 11. The steel product is processed from the piece of cast 25.;COPYRIGHT: (C)2003,JPO