This study investigates the microstructure and local corrosion behavior of an Al–Mg–Si–Cu alloy, which has been subjected to cold-rolling with different deformation strain ratios (DSRs) and followed by artificial aging. Accelerated corrosion tests show that peak-aged samples with a small DSR (5–10%) are sensitive to inter-granular corrosion (IGC) along both the normal and rolling directions. When the DSR increases to medium strength (20–40%), IGC sensitivity decreases along both directions and corrosion propagates anisotropically. When the DSR is 60–80%, IGC sensitivity along the normal direction continues to decrease, but increases along the rolling direction, indicating pronounced corrosion anisotropy. Microstructural characterization reveals the decreased IGC sensitivity is mainly attributed to a reduction in element segregation at high-angle grain boundaries and the kinked and discontinuous grain boundary corrosion paths. The increased IGC sensitivity along the rolling direction could be related to the significantly flattened grains.

本研究研究了经过不同变形应变比 (DSR) 冷轧和人工时效处理的 Al-Mg-Si-Cu 合金的微观结构和局部腐蚀行为。加速腐蚀试验表明，具有小 DSR (5-10%) 的峰值时效样品对沿法向和轧制方向的晶间腐蚀 (IGC) 敏感。当 DSR 增加到中等强度 (20-40%) 时，IGC 灵敏度沿两个方向都降低，腐蚀以各向异性方式传播。当DSR为60%~80%时，沿法线方向的IGC灵敏度继续降低，但沿轧制方向增加，表明腐蚀各向异性明显。微观结构表征表明，IGC 敏感性的降低主要归因于大角度晶界处元素偏析的减少以及扭结和不连续的晶界腐蚀路径。沿轧制方向增加的 IGC 敏感性可能与显着扁平的晶粒有关。