To provide a refining method by which Fe-base, Ni-base and Co-base alloy materials, such as stainless steels and various superalloys, having ultrahigh purity of an impurity level satisfying (C+O+N+S+P)<100 ppm and Ca<10 ppm and also having a large ingot size can be manufactured.
In this refining method, after raw materials are melted by a cold crucible vacuum induction melting process using a water-cooled copper crucible, a refining flux which is composed of metallic elements of specific groups in the periodic table, or oxides thereof, or a halide as a simple substance selected from a group of halides, or a mixture consisting of the halide, the metallic element and the oxide is added to undergo melting. After primary melting is performed in a state where the molten metal and the refining flux are kept in contact with each other for ≥5 min, the molten metal is tapped and solidified in a mold into a primary ingot. Subsequently, as secondary melting, while sequentially melting the primary ingot by an electron beam melting process under low pressure in a water-cooled copper vessel, the resultant molten metal is extracted from its exit side while being solidified to undergo ingot making.
| JPH01208427 | METHOD FOR MELTING METAL |
| JPS5914529 | [Title of the Invention] Fluid refining transfer method |
| JPS63166936 | MANUFACTURE OF INGOT OF METAL OR ALLOY |
SODO TATSUHIKO
NAKAYAMA JUNPEI
KIUCHI KIYOSHI
JAPAN ATOMIC ENERGY AGENCY
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