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