HIGH STRENGTH AND HIGH TOUGHNESS ALUMINUM ALLOY FORGING MATERIAL HAVING EXCELLENT CORROSION RESISTANCE, PRODUCTION METHOD THEREFOR, AND SUSPENSION COMPONENT

摘要

PROBLEM TO BE SOLVED: To provide a high strength and high toughness Al-Mg-Si-based aluminum alloy forging material having excellent corrosion resistance, which has strength and toughness more improved than those of a conventional Al-Mg-Si based alloy, i.e., can obtain high strength of ≥350 MPa by proof stress and high toughness of ≥20 J/cm2 by Charpy impact value, and is suitably usable as a vehicle structural member.;SOLUTION: The aluminum alloy forging material has a composition comprising 0.7 to 1.3% Si, 0.55 to 0.95% Mg, 0.27 to 0.43% Cu, 0.17 to 0.43% Mn, 0.07 to 0.23% Cr, 0.10 to 0.24% Zr, and the balance Al with inevitable impurities, and satisfying [Si%]×1.73-[Mg%]0.35%. The central part of the thickness of the cross-section has a subgrain structure with an average crystal grain size of ≤10 μm, and the ratio of the subgrain structure occupied in the cross-section is ≥70%.;COPYRIGHT: (C)2013,JPO&INPIT