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:
Jan. 24, 2017
Filed:
Jan. 14, 2014
Kobe Steel, Ltd., Kobe-shi, JP;
Takahiro Shikama, Shimoneseki, JP;
Shinji Yoshihara, Shimonoseki, JP;
Kobe Steel, Ltd., Kobe-shi, JP;
Abstract
An aluminum alloy member resistant to cracking and having high strengths and excellent stress corrosion cracking resistance is manufactured by expanding a 7xxx aluminum alloy hollow extrusion at a rate of 5% or more. Specifically, a 7xxx aluminum alloy hollow extrusion containing Zn of 3.0-9.5%, Mg of 0.4-2.5%, Cu of 0.05-2.0%, and Ti of 0.005-0.2%, in mass percent, and prepared through press quenching is subjected to a reversion treatment, to pipe expansion within 72 hours after the reversion treatment, and to temper aging. The reversion treatment includes heating at a temperature rise rate of 0.4° C./second or more, holding in a temperature range of 200-550° C. for longer than 0 second, and cooling at a rate of 0.5° C./second or more. The ratio Y (σ/σ) of the tensile residual stress σto the 0.2% yield stress σafter temper aging and the total content X of Mg and Zn satisfy Expression (1):Y≦−0.1X+1.4   (1).