METHOD FOR PRODUCING 7000-SERIES ALUMINUM ALLOY MEMBER EXCELLENT IN STRESS CORROSION CRACKING RESISTANCE

摘要

The stress corrosion cracking resistance of an aluminum alloy member consisting of 7000-series aluminum alloy extruded shape is improved. At least one region of a quenched aluminum alloy extruded shape is subjected to a restoring treatment of heating at a temperature-raising rate of 0.4° C./second or more, holding at a temperature ranging 300 to 590° C. for a time longer than zero second and cooling at a cooling rate of 0.5° C./second or more. A plastic working is applied to the region within 72 hours. The region is subjected to a heat treatment of heating at a temperature-raising rate of 0.4° C./second or more, holding at a temperature ranging 300 to 590° C. for a time longer than zero second and not longer than 300 seconds and cooling at a cooling rate of 2000° C./minute or less. The whole of the aluminum alloy extruded shape is subjected to an artificial aging treatment.

主权项

1. A method for producing an aluminum alloy member consisting of a 7000-series aluminum alloy extruded shape excellent in stress corrosion cracking resistance, comprising:
quenching the aluminum alloy extruded shape; subjecting the quenched aluminum alloy extruded shape to natural aging for 12 hours or longer; subjecting at least one region of the aluminum alloy extruded shape subjected to the natural aging to a restoring treatment of heating the region at a temperature-raising rate of 0.4° C./second or more, holding the region in a temperature range of 300 to 590° C. for a time longer than zero second and cooling the region at a cooling rate of 0.5° C./second or more; applying a plastic working to the region within 72 hours of the end of the restoring treatment; subjecting the region to a heat treatment of heating the region at a temperature-raising rate of 0.4° C./second or more, holding the region in a temperature range of 300 to 590° C. for a time longer than zero second and not longer than 300 seconds and cooling the region at a cooling rate of 2000° C./minute or less; and subjecting the whole of the aluminum alloy extruded shape subjected to the heat treatment to an artificial aging treatment.