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:
May. 26, 1981
Filed:
Mar. 06, 1980
Takeshi Takeuchi, Ichikawa, JP;
Hisao Takamura, Ichikawa, JP;
Kiyoshi Takatsu, Ichikawa, JP;
Hidehiro Shibata, Ichikawa, JP;
Nisshin Steel Co., Ltd., Tokyo, JP;
Abstract
This invention relates to a method for coloring stainless steel by controlling the potential difference between the surface of the stainless steel being colored and a reference electrode in a coloring liquor, characterized by differentiating a potential-time curve showing the variation with time of the potential difference between the surface of the stainless steel and the reference electrode by time to prepare the differentiation curve thereof and removing the stainless steel from the coloring liquor when the potential difference has changed from the coloring starting point that is the inflexion point on this differentiation curve, at which the variation amount of the potential per unit time changes from a falling tendency to a rising tendency, by a predetermined amount associated with the desired color.