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.
Patent No.:
Date of Patent:
Jul. 22, 1997
Filed:
May. 16, 1996
Applicant:
Inventors:
Assignee:
Daido Hoxan Inc., Sapporo, JP;
Primary Examiner:
Int. Cl.
CPC ...
C23C / ;
U.S. Cl.
CPC ...
148228 ; 148231 ; 148232 ;
Abstract
A method of nitriding steel which comprises reacting the steel surface with nitrogen so as to form a hard nitrided layer, and, prior to nitriding, holding steel under a gas atmosphere containing fluorine compound gas or fluorine gas and also containing air of 0.5 to 20 volume % of the total or oxygen gas of 0.1 to 4 volume % of the total with heating, whereby occurrence of uneven nitriding is prevented and at the same time savings in consumption of expensive fluorine- or fluoride-containing gas can be realized.