运用光学显微镜（OM）、扫描电镜（SEM）、透射电镜（TEM）和X射线衍射仪（XRD）对近海含SO₂环境中使用过的高压隔离开关2A12-T4铝合金部件的组织以及腐蚀特征进行分析。结果表明：2A12-T4铝合金晶粒沿变形方向拉长，并形成了一定数量的亚晶；主要的第二相是T相，并有大量的位错缠绕在T相周围。2A12-T4铝合金主要的腐蚀产物是Al（OH）₃和Al₂（SO₄）₃·14H₂O，腐蚀主要受到湿润条件下Cl^-和SO₂两种腐蚀性介质的联合作用，而拉长变形的晶粒以及第二相粒子则加速了腐蚀。

The microstructure and corrosion characteristics of 2A12-T4 aluminum alloy high voltage isolation switch parts used in offshore environment with SO₂ were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that the grains of 2A12-T4 aluminum alloy were elongated along the deformation direction, and a certain number of sub-crystals formed. The main second phase was T phase surrounded by a mass of dislocations. The main corrosion products of 2A12-T4 aluminum alloy were Al(OH)₃ and Al₂(SO₄)₃·14H₂O. The corrosive behavior was mainly controlled by Cl^- and SO₂ in moist environment. Additionally, the deformed elongated grains and the second phase particles accelerated the corrosion.