【摘要】 以中强Al-Zn-Mg合金为研究对象，采用晶间腐蚀、电化学极化曲线测试、慢应变速率拉伸等试验，结合OM、TEM、SEM、EBSD等组织分析方法研究时效处理和晶粒组织对合金腐蚀性能的影响。研究结果表明：随着双级时效时间的延长，再结晶晶粒合金的抗腐蚀性能逐渐提升，从欠时效处理到过时效处理，晶间腐蚀等级由4级降为2级，电化学腐蚀电流密度由27.71μA/cm~2降为0.098μA/cm~2，应力腐蚀指数由79.15降至18.40；纤维晶粒合金与同时效阶段的再结晶晶粒合金相比，其抗腐蚀性能显著提升，其中，晶间腐蚀最大深度降低了35.9%，电化学腐蚀电流密度降低了81.4%，年腐蚀速率降低了81.9%，应力腐蚀敏感指数降低了46.2%。中强Al-Zn-Mg合金腐蚀性能的提升主要源于其较低的再结晶分数和较低的大角度晶界占比。更多还原

【Abstract】 The effects of aging treatment and grain structure on the corrosion performance of the alloy were investigated by using the medium-strength Al-Zn-Mg alloy as the research object, and using intergranular corrosion,electrochemical polarization curve test, and slow strain rate tensile tests, combined with OM, TEM, SEM, and EBSD observations, respectively. The results show that the corrosion resistance of the recrystallized grain alloy gradually improves with the extension of the double-stage aging time, the intergranular corrosion grade decreases from grade 4to grade 2, the electrochemical corrosion current density decreases from 27.71 μA/cm~2 to 0.098 μA/cm~2, and the stress corrosion sensitivity factor decreases from 79.15 to 18.40 when the treatment method changes from the underaging treatment to the over-aging treatment. The corrosion resistance of the fiber grain alloy is significantly improved compared with that of the recrystallized grain alloy at the same aging stage, including a 35.9% reduction in the maximum depth of intergranular corrosion, an 81.4% reduction in the electrochemical corrosion current density, an 81.9% reduction in the annual corrosion rate, and a 46.2% reduction in the stress corrosion sensitivity index. The improvement in corrosion performance is mainly due to the lower recrystallization fraction and lower percentage of large-angle grain boundary of the medium-strength Al-Zn-Mg alloy.更多还原