The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Sep. 27, 1983

Filed:

Apr. 27, 1981
Applicant:
Inventors:

Robert G Bowes, Otley, West Yorkshire, GB;

Keith Bennett, Long Lee, Keighley, West Yorkshire, GB;

Paul F Stratton, Bradley Grange, Bradley, Huddersfield, West Yorkshire, GB;

Assignee:

Other;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148 165 ; 148 166 ;
Abstract

Ferrous metal is treated by austenitic nitro-carburizing in a heat treatment furnace. A suitable atmosphere is created by admitting to the furnace nitrogen; ammonia; and a liquid or vaporous organic compound of carbon, hydrogen and oxygen. The atmosphere is maintained at a temperature in the range 690.degree. to 750.degree. C. The organic compound is typically methanol and the atmosphere typically comprises nitrogen, carbon monoxide, hydrogen and free ammonia as well as small amounts of methane, carbon dioxide and water vapor. After being removed from the furnace, the ferrous metal is quenched. It has an outer surface layer of white, scuff-resistant, epsilon compound and an inner carbo-nitrided case containing austenitic and martensitic zone. The ferrous metal may then be treated to convert austenite to martensite or lower bainite.


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