Atmospheres for heat treating non-ferrous metals and alloys
US5298090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1992 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Dec 22, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D1/763
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for producing low-cost atmospheres suitable for annealing, brazing, and sintering non-ferrous metals and alloys from non-cryogenically produced nitrogen containing up to 5%, residual oxygen is disclosed. According to the process, suitable atmospheres are produced by 1) pre-heating the non-cryogenically produced nitrogen stream containing residual oxygen to a desired temperature, 2) mixing it with more than a stoichiometric amount a hydrocarbon gas, 3) passing it through a reactor packed with a platinum group of metal catalyst to reduce the residual oxygen to very low levels and convert it to a mixture of moisture and carbon dioxide, and 4) using the reactor effluent stream for annealing, brazing, and sintering non-ferrous metals and alloys in a furnace. The key features of the disclosed process include 1) pre-heating the non-cryogenically produced nitrogen containing residual oxygen to a certain minimum temperature, 2) adding more than a stoichiometric amount of a hydrocarbon gas to the pre-heated nitrogen stream, and 3) using a platinum group of metal catalyst to initiate and sustain the reaction between oxygen and the hydrocarbon gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.