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:
Apr. 18, 2000
Filed:
Feb. 16, 1998
Applicant:
Inventors:
Takeshi Naito, Tokyo, JP;
Kouichi Ogihara, Tokyo, JP;
Akihiro Wakatsuki, Tokyo, JP;
Tadanori Nakahiro, Tokyo, JP;
Hideki Inoue, Tokyo, JP;
Yoshio Nakashima, Tokyo, JP;
Assignee:
Dowa Mining Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23C / ; C23C / ;
U.S. Cl.
CPC ...
148215 ; 148216 ; 148235 ; 266251 ; 266252 ;
Abstract
In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace, and the supply of the hydrocarbon series gas is stopped either when the quantity of a residual CH.sub.4 in the furnace is changed to increasing from decreasing, or when a partial pressure of oxygen in the furnace reaches a predetermined value.