Atmospheres for decarburize annealing steels
US5401339A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1994 |
| Grant date | Mar 28, 1995 |
| Priority date | — |
| Expiry date | Feb 10, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D3/04
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing low-cost atmospheres suitable for decarburize annealing carbon steels from non-cryogenically generated nitrogen containing up to 1.54 residual oxygen by catalytically deoxygenating a non-cryogenically generated nitrogen stream at low temperatures with a hydrocarbon gas and mixing the deoxygenated stream with an economical amount of hydrogen prior to introduction into the furnace for annealing. The process includes the use of 1) hydrocarbon gas to convert residual oxygen to a mixture of carbon dioxide and moisture at low temperatures and 2) mixing the deoxygenated stream with a sufficient amount of hydrogen to maintain a pH.sub.2 /pH.sub.2 O ratio of at least 2 in the furnace.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.