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. 18, 2012
Filed:
Apr. 26, 2007
Hiroyuki Masuoka, Hiroshima, JP;
Shoichiro Taira, Hiroshima, JP;
Yoshiharu Sugimoto, Okayama, JP;
Naoto Yoshimi, Hiroshima, JP;
Masayasu Nagoshi, Hiroshima, JP;
Wataru Tanimoto, Hiroshima, JP;
Hiroyuki Masuoka, Hiroshima, JP;
Shoichiro Taira, Hiroshima, JP;
Yoshiharu Sugimoto, Okayama, JP;
Naoto Yoshimi, Hiroshima, JP;
Masayasu Nagoshi, Hiroshima, JP;
Wataru Tanimoto, Hiroshima, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A method of manufacturing a hot dip galvannealed steel sheet, including the steps of: subjecting a steel sheet to hot dip galvanizing to manufacture a hot dip galvanized steel sheet; heating the hot dip galvanized steel sheet for alloying; subjecting the hot dip galvanized steel sheet to temper rolling; bringing the temper-rolled hot dip galvanized steel sheet into contact with an acid solution containing at least one ion selected from the group consisting of Zr ions, Ti ions, and Sn ions to thereby form an acid solution film on the surface of the steel sheet; after completion of the contact, a state where the acid solution film is formed on the surface of the steel sheet is held for at least 1 second; and washing with water the hot dip galvanized steel sheet after holding, to thereby form a Zn oxide layer having a thickness of 10 nm or more on the surface of the galvanized steel sheet. The hot dip galvannealed steel sheet has an oxide layer having an average thickness of 10 nm or more on the surface of the plated steel sheet.