Method for the thermal treatment of metal

US6406560B1 · kind B1 · utility

Assignee

• Ipsen International, GmbH · US

Inventors

• Wolfgang Lerche · Kleve, DE
• Bernd Edenhofer · Kleve, DE
• Michael Lohrmann · Kleve, DE

Key dates

• Filing date: Apr 28, 2000
• Grant date: Jun 18, 2002
• Expiry date: Apr 28, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C8/32
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method is provided for the thermal treatment of metal workpieces in a gas atmosphere containing nitrogen, in particular for nitrocarburizing iron articles. In order to obtain enhanced resistance to wear and corrosion in the treated workpieces, the nitrogen and carbon content present in the connecting layer of the case of the treated workpieces are intentionally adjusted by appropriately selecting the nitride coefficient KN and the carburizing coefficient KC of a reaction gas that contains ammonia, whereby hydrocarbons are added to the reaction gas for producing a relatively high carbon content in the connecting layer.