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:
Aug. 26, 2008
Filed:
Apr. 28, 2003
Showa Tachisato, Yamatokoriyama, JP;
Showa Tachisato, Yamatokoriyama, JP;
Koyo Thermo Systems Co., Ltd., Nara, JP;
Abstract
A method of gas carburizing is carried out at a carburizing temperature which is not higher than a peritectic point temperature at which δ iron and liquid phase are transformed into γ iron and not less than a eutectic point temperature at which liquid phase is transformed into γ iron and cementite. The method comprises the step of predetermining the limiting carburizing conditions at which the surface layer of a sample of a steel treatment object present in a carburizing atmosphere is austenitized without melting and the step of gas carburizing the treatment object under carburizing conditions which are set so as not to contradict the limiting carburizing conditions, at a carburizing temperature which is not higher than the peritectic point temperature and not less than the eutectic point temperature. The limiting carburizing conditions comprise an upper limit value of a partial pressure of carburizing gas at which the surface layer of the sample is austenitized without melting.