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. 04, 2004
Filed:
Nov. 06, 2001
Masaya Yamamoto, Sakai, JP;
Mitsuo Asabuki, Sakai, JP;
Shigeyasu Morikawa, Sakai, JP;
Shinya Furukawa, Sakai, JP;
Hirofumi Taketsu, Sakai, JP;
Nisshin Steel Co., Ltd., Tokyo, JP;
Abstract
A chemically processed steel sheet comprising a steel base coated with an Al—Si alloy plating layer, whose Si content is preferably adjusted to approximately 5-13 mass % as a whole and to approximately 7-80 mass % at a surface, and a converted layer generated on the surface of the plating layer. The converted layer contains both soluble and scarcely-soluble compounds. The soluble compound such as a manganese oxide or hydroxide or a valve metal fluoride is once dissolved to water in an atmosphere and then re-precipitated as scarcely-soluble compounds at defective parts of the converted layer. The scarcely-soluble compounds act as a barrier for corrosion-prevention of a base steel. Due to the re-precipitation, that is self-repairing faculty, excellent corrosion resistance of the converted layer is still maintained even after defects are introduced therein during plastic deformation of the steel sheet.