Patent ID: 7967057
Filing Date: 2011-06-28
Classification: C04B,C21C,C22B,F27B,F27D,H05B,Y02P,Y10T

Abstract:
1. A method for producing ultrahigh-purity Fe-base, Ni-base, and Co-base alloying materials, said method comprising: (1) melting a high-purity main raw material and an alloying raw material, refined in an inert gas atmosphere by a cold-crucible vacuum induction-melting method, using a water-cooled copper crucible to form a melt; (2) subsequently adding a refining flux selected from the group consisting of halides of metal elements, metal elements and oxides of metal elements, which metal elements are selected from the group consisting of metal elements of groups IA, IIA, and IIIA of the Periodic Table, and mixtures thereof, to the melt; (3) executing a primary melting by holding the melt in contact with the refining flux for not less than 5 minutes before tapping the primary melt; (4) causing the primary melt to undergo solidification inside a mold, thereby producing a primary ingot; and (5) subsequently executing a secondary melting by an electron-beam melting method, wherein while the primary ingot is sequentially melted in a water-cooled copper mold at a pressure not higher than 0.5 Pa, the secondary melt in solidified state is pulled out from an outlet side of the water-cooled copper mold, thereby forming an ingot product.