Aluminum alloy forging member and process for producing the same

aa a The present invention provides an aluminum alloy forging material having enhanced strength, toughness, and corrosion resistance, and a method of producing the material. An aluminum alloy forging material produced with specified components under specified conditions has an arm portion including a relatively narrow and thick peripheral rib and a thin and relatively wide central web having a thickness of 10 mm or less and having a substantially H-shaped sectional form. In a width-direction section of a maximum stress producing site of the rib , the density of crystals observed in the structure of a sectional portion where the maximum stress is produced, the spacing of grain boundary precipitates and the size and density of dispersed particles observed in the structure of a sectional portion including a parting line, the recrystallization ratio observed in each of the sectional portions and of the rib, and the recrystallization ratio observed in a sectional portion of the web adjacent to the sectional structure of the rib in the width direction are defined for enhancing the strength, toughness, and corrosion resistance of the aluminum alloy forging material.