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:
Jun. 22, 2004
Filed:
Feb. 11, 2002
Hidetoshi Shindou, Hyogo, JP;
Kiyokazu Isizuka, Hyogo, JP;
Keiichi Sanada, Hyogo, JP;
Kazuo Takahashi, Hyogo, JP;
Teruaki Yamada, Hyogo, JP;
Daisuke Ito, Hyogo, JP;
Shigekazu Ooba, Osaka, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
The aim of the present invention is to provide a phosphate treated zinc coated steel sheet with excellent workability. A steel sheet coated with a zinc based alloy has a phosphate treated coating on the surface thereof. The phosphate treated coating comprises mainly granulated crystals, specifically, crystals in which the average ratio of the major axis to the minor axis is not less than 1.00 and not more than 2.90. Moreover, the method for producing the phosphate treated coating uses a phosphate treatment solution in which the amount of Mg ions is ≧6 g/l and the amount of Zn ions is ≧0.5 g/l, or a phosphate treatment solution in which the amount of Mg ions is ≧10 g/l, the amount of Zn ions is 0≦ and <0.5 g/l, and the amount of nitric acid ions is ≧40 g/l. Moreover, the phosphate treated zinc coated steel sheet also has excellent corrosion resistance as the amount of Mg in the phosphate treated coating is not less than 10 mg/m , and has excellent weldability as the coating amount is controlled to 0.5 to 3.0 g/m .