Induction melting apparatus employing halide type crucible, process for producing the crucible, method of induction melting, and process for producing ingot of ultrahigh-purity Fe-, Ni-, or Co-based alloy material
US7967057B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 2006 |
| Grant date | Jun 28, 2011 |
| Priority date | — |
| Expiry date | Nov 15, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is described a method for producing ultrahigh-purity Fe-base, Ni-base, and Co-base alloying materials to achieve impurity levels of (C+O+N+S+P)<100 ppm, and Ca<10 ppm, in the form of a large ingot, using a refining flux while forcibly cooling the crucible. A refining flux selected from the group consisting of metal elements of the Groups IA, IIA, and IIIA of the Periodic Table, oxides thereof, halides thereof, and mixtures thereof, is added to the molten metal during primary melting and the molten metal is held in contact with the refining flux for at least 5 minutes before tapping. Thereafter, the molten metal is caused to undergo solidification inside a mold, thereby producing a primary ingot. Subsequently, secondary melting is executed by an electron-beam melting method whereby while the primary ingot is sequentially melted in a water-cooled copper mold at a low pressure, the molten metal as-solidified state is pulled out from an outlet side of the water-cooled copper mold, thereby forming an ingot product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.