ALUMINUM ALLOY FORGING MEMBER AND PROCESS FOR PRODUCING THE SAME

摘要

This invention provides an aluminum alloy forging material, which has realized enhanced strength, enhanced toughness, and enhanced corrosion resistance, and a process for producing the same. The aluminum alloy forging material is produced so as to have a specific chemical composition under specific production conditions and is an aluminum alloy forging material (1) which has an arm part (2) of an approximately H shape in cross section and comprises a peripheral rib (3) having a relatively narrow width and a large thickness and a central web (4) having a small thickness of 10 mm or less and a relatively large width. The enhanced strength, enhanced toughness and enhanced corrosion resistance have been realized by specifying the density of a crystallized product observed in a microstructure in a cross-sectional site (7), where the maximum stress occurs, in the cross section in the widthwise direction at the maximum stress producing site in a rib (3a), the spacing between grain boundary precipitates observed in a microstructure at a cross-sectional site (8) including a parting line and the size and density of dispersed particles, the proportion of recrystallization observed in cross-sectional microstructures (7, 8) of the ribs, and the proportion of recrystallization observed in a cross-sectional microstructure (9)in the widthwise direction of the web (4a) adjacent to the cross-sectional microstructure of the rib (3a).