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:
Sep. 24, 1985
Filed:
Apr. 27, 1984
Tomihiro Hara, Yokohama, JP;
Takeshi Adaniya, Yokohama, JP;
Masaru Sagiyama, Yokohama, JP;
Tsutomu Watanabe, Fukuyama, JP;
Takashi Shimoma, Yokohama, JP;
Masaru Nabatame, Fukuyama, JP;
Nippon Kokan Kabushiki Kaisha, Tokyo, JP;
Abstract
An iron-zinc alloy electro-galvanized steel sheet having a plurality of iron-zinc alloy coatings, which comprises: at least one iron-zinc alloy coating as the lower layer, formed on the surface of a steel sheet, and at least two iron-zinc alloy coatings as the upper layer, formed on the at least one iron-zinc alloy coating as the lower layer. The ratio of iron content to the coating weight of each of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 15 wt. %, and the total coating weight of the at least one iron-zinc alloy coating as the lower layer is within the range of from 1 to 50 g/m.sup.2 per side of the steel sheet. The ratio of iron content to the coating weight of each of the at least two iron-zinc alloy coatings as the upper layer is over 15 wt. %, the ratio of iron content to the coating weight gradually increases from the innermost coating toward the outermost coating of the at least two iron-zinc alloy coatings as the upper layer, the difference in the ratio or iron content to the coating weight between two adjacent coatings of the at least two iron-zinc alloy coatings as the upper layer is within the range of from 1 to 15 wt. %, and the total coating weight of the at least two iron-zinc alloy coatings as the upper layer is within the range of from 1 to 40 g/m.sup.2 per side of the steel sheet. The difference in the ratio of iron content to the coating weight between the uppermost coating of the at least one iron-zinc alloy coating as the lower layer and the lowermost coating of the at least two iron-zinc alloy coatings as the upper layer is within the range of from 1 to 15 wt. %. The sum of the total coating weight of the at least one iron-zinc alloy coating as the lower layer and the total coating weight of the at least two iron-zinc alloy coatings as the upper layer is within the range of from 10 to 75 wt. % per side of the steel sheet.