Process for reducing oxides contained in iron powder without substantial decarburization thereof
US5234489A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 27, 1992 |
| Grant date | Aug 10, 1993 |
| Priority date | — |
| Expiry date | May 27, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2201/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process is provided for preparing carbon-containing substantially oxide-free iron powders or iron-based powders or both wherein oxygen impurities from an iron powder are removed without substantial decarburization, by heating the iron powder or iron-based powders or both under a substantially pure hydrogen atmosphere from ambient temperatures to a first intermediate temperature in an enclosure, then replacing the substantially pure hydrogen atmosphere by a substantially pure nitrogen atmosphere in the enclosure and then heating the powder to a second temperature which is higher that the first intermediate temperature, then cooling down the powder under an inert atmosphere to at least a temperature where substantially no more oxidation of the powder occurs, then removing the powder from the enclosure, the first and second temperatures being sufficient to reduce substantially all oxide impurities in the powder without substantial decarburization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.