对ZA12－T451板材经铬酸阳极氧化后局部出现黑斑缺陷进行了试验研究.结果表明,该缺陷与强化相析出有关,金相与电镜观察证明,该区域是析出质点富集区经氧化形成的.“,”The examination was made on the black spot defects which occurred on the local areas of the surface of 2A12-T451 plate after anodized in chromic acid. It was demonstrated that the defects are related to the precipitation of hard particles. The metalurgraphic and electron microscopic inspection found that the black spot defects are formed by the oxidation of particle enriched zone.