In-situ generation of heat treating atmospheres using a mixture of non-cryogenically produced nitrogen and a hydrocarbon gas
US5259893A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1991 |
| Grant date | Nov 9, 1993 |
| Priority date | — |
| Expiry date | Nov 5, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D1/26
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a predetermined amount of a hydrocarbon gas, feeding the gaseous mixture through a nonconventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as a mixture of moisture and carbon dioxide, a mixture of moisture, hydrogen, carbon monoxide, and carbon dioxide, or a mixture of carbon monoxide, moisture, and hydrogen, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals, sintering metal and ceramic powders, and sealing glass to metals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.