Heat treatment conditions for forming AA6022 aluminum sheet in a forming process with intermediate heat treatment

¹ Application Technology Center, Technical Development Group, KOBE STEEL, LTD. 1-5-5, Takatsukadai, Nishi-ku, Kobe, HYOGO, 6512271 JAPAN
² Aluminum Sheets & Coils Development Department, Moka Works, Steel & Aluminum Business, KOBE STEEL, LTD., 15, Kinugaoka, Moka-city, TOCHIGI 3214367 JAPAN

^* Corresponding author: nakamura.shuki@kobelco.com

Abstract

The series of processes of pre-forming, heat treatment and forming for AA5182-O is known as one of forming process. However, it is possible that the appropriate intermediate heat temperature is different from that of AA5182-O when the process is applied to 6000 series aluminum alloy because it is age-hardening material. In this study, we examined the appropriate intermediate heat treatment temperature to improve the total elongation when the process was applied to AA6022-T4. The test was performed in the following procedure, preliminary tensile test, intermediate heat treatment, and tensile test. First, test specimens were subjected to a defined strain value. Next, test specimens were heat treated at several target temperatures as an intermediate heat treatment. The test specimen was removed from the furnace as soon as reaching the target temperature, and water-cooled immediately. Finally, tensile test was performed up to rupture of the specimen. As a result of the experiments, appropriate intermediate heat temperature to improve the total elongation was clarified when the process is applied to AA6022-T4. The appropriate temperature was different from that of AA5182-O.