7xxx series aluminum alloy member excellent in stress corrosion cracking resistance and method for manufacturing the same
US10144997B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2017 |
| Grant date | Dec 4, 2018 |
| Priority date | — |
| Expiry date | Nov 10, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C21/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An aluminum alloy member resistant to cracking and having high strengths and excellent stress corrosion cracking resistance is manufactured by crushing a 7xxx aluminum alloy extrudate. Specifically, a 7xxx aluminum alloy extrudate containing Zn of 3.0-8.0%, 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 crushing within 72 hours after the reversion treatment, and then to 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 of the tensile residual stress σrs to the 0.2% yield stress σ0.2 after aging and the total content X of Mg and Zn satisfy a condition specified by Expression (1): Y≤−0.1X+1.4 (1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.