Method of manufacturing ultra low carbon ferritic stainless steel
US8277537B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2008 |
| Grant date | Oct 2, 2012 |
| Priority date | — |
| Expiry date | Jan 8, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of manufacturing a ferritic stainless steel containing an ultra low level of carbon concentration in molten steel within time shorter than existing technology by controlling content, appropriate composition, and liquid-state fraction, etc., of Cr2 O3 in slag to maximize vacuum decarburization refining efficiency, the method comprising: tapping molten steel to a ladle in a non-deoxidized state after pre-decarburization and denitrification in an ARGON OXYGEN DECARBURIZATION refining furnace and then removing non-deoxidized slag; placing the ladle in a vacuum furnace, reducing pressure and then blowing-in oxygen gas from the upper of the molten steel through a lance; creating Al2 O3 by injecting Al at point of time of beginning of oxygen blowing; forming CaO—Al2 O3 —Cr2 O3 —MgO-based slag by injecting calcium oxide at point of time of completion of the oxygen blowing; and supplying inert gas through a porous plug on a bottom of the ladle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.