目的 采用四因素三水平正交试验，研究氢氧化钠、鞣酸、磷酸二氢钠浓度和处理时间对在AZ91镁合金氧化膜耐蚀性及钙、磷含量的影响。方法 采用扫描电子显微镜、能谱仪和电化学工作站研究了工艺条件对氧化膜的表面形貌、成分和耐蚀性的影响。结果 影响氧化膜耐蚀性的主次顺序为NaH2PO4浓度>鞣酸浓度>氧化时间>氢氧化钠浓度，对氧化膜中Ca含量的影响主次顺序为氢氧化钠浓度>NaH2PO4浓度>氧化时间>鞣酸浓度，而对氧化膜中P含量的影响主次顺序为NaH2PO4浓度>鞣酸浓度>氢氧化钠浓度>氧化时间。结论 NaH2PO4对氧化膜耐蚀性的影响最大，鞣酸可有效提高氧化膜的耐蚀性，浓度越高氧化时间越长，其耐蚀性越好。

The work aims to study the effects of NaOH concentration, tannic acid concentration, NaH2PO4 concentration and treatment time on corrosion resistance as well as calcium and phosphorus content in oxide film on AZ91 magnesium alloys were studied by means of an orthogonal experiment of four factors with three levels. Effects of process conditions on surface morphology, composition and corrosion resistance of oxide film were researched by scanning electron microscope (SEM), energy disperse spectroscopy and electrochemical workstation. Primary and secondary order of factors affecting corrosion resistance of oxide film was: NaH2PO4 concentration>tannic acid concentration>treatment time>NaOH concentration. For calcium content in the oxide film: NaOH concentration>NaH2PO4 concentration>treatment time>tannic acid concentration. For phosphorus content: NaH2PO4 concentration>tannic acid concentration>NaOH concentration>treatment time. The NaH2PO4 has a greatest effect on the corrosion resistance of oxide film while tannic acid can effectively improve the corrosion resistance of the oxide film. The oxide film has better corrosion resistance as tannic acid concentration increases and oxidation time extends.