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:
Nov. 27, 2012
Filed:
May. 04, 2004
Showa Tachisato, Yamatokoriyama, JP;
Showa Tachisato, Yamatokoriyama, JP;
Koyo Thermo Systems Co., Ltd., Nara, JP;
Abstract
In a first step of a method of gas carburizing, a steel treatment object is heated in a carburizing atmosphere comprising a carburizing gas until the surface carbon concentration of the treatment object reaches the final target value that is not higher than the solid solubility limit at a carburizing temperature that is not higher than the peritectic point, at which steel transforms from δ iron and liquid phase to γ iron, and is not less than the eutectic point, at which steel transforms from liquid phase to γ iron and cementite. In a second step the gas carburizing is advanced after the first step so that the carburizing depth of the treatment object increases while the surface carbon concentration of the treatment object is kept at the final target value by reducing the carbon potential of the carburizing gas with the lapse of time.