Vacuum carburizing with napthene hydrocarbons
US6991687B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 2002 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Dec 4, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C8/22
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Vacuum carburizing of ferrous workpieces is performed at low pressure in a vacuum furnace using a napthene hydrocarbon as the carburizing medium. The furnace is constructed to be generally transparent to the napthene so that cracking tends to occur at the workpiece which functions as a catalyst to minimize carbon deposits. The napthene is supplied in liquid form to fuel injectors which inject the liquid napthene as a vapor at duty cycles and firing orders to produce a uniform dispersion of the hydrocarbon gas about the work resulting in uniform carburizing of the workpieces. An in-situ methane infrared sensor controls the process. Hydrogen is added to the napthene to either assure full carbon potential and produce methane or to perform variable carburizing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.