Citric acid passivation is an attractive alternative to increase the corrosion resistance of stainless steels. In this work, the correlation of passive film composition and the corrosion properties of citric acid‐passivated AISI 316L stainless steel samples was assessed. The concentration of citric acid in the passivating solution was varied from 10 to 30 wt.%. Passive film composition was examined by X‐ray photoelectron spectroscopy. The corrosion behavior was investigated by potentiodynamic polarization curves. The citric acid passivation treatment led to Cr₂O₃ enrichment of the passive film, especially for the 20‐wt.% concentration. By increasing the citric acid concentration to 30 wt.%, the corrosion resistance decreased. In addition to chromium compounds, the passivation treatment also affected the relative concentrations of Fe, Mo, and Ni compounds in the passive films. The formation of Mo oxides was triggered at citric acid concentrations of 10 and 20 wt.%, contributing to slower anodic dissolution rate. The corrosion resistance of the passivated samples was favored as the relative concentration of Fe oxides (FeO and Fe₂O₃) increased with respect to FeOOH.

中文翻译：

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钝化膜的成分与柠檬酸钝化的AISI 316L不锈钢的耐蚀性之间的相互作用

柠檬酸钝化是增加不锈钢耐腐蚀性的一种有吸引力的替代方法。在这项工作中，评估了钝化膜成分与柠檬酸钝化的AISI 316L不锈钢样品的腐蚀性能之间的相关性。钝化溶液中柠檬酸的浓度为10至30重量％。通过X射线光电子能谱检查了钝化膜的组成。通过电位动力学极化曲线研究了腐蚀行为。柠檬酸钝化处理产生Cr ₂ O ₃钝化膜的富集，尤其是浓度为20 wt。％时。通过将柠檬酸浓度增加至30重量％，耐腐蚀性降低。除铬化合物外，钝化处理还影响钝化膜中Fe，Mo和Ni化合物的相对浓度。柠檬酸浓度为10和20 wt。％时会触发Mo氧化物的形成，这有助于降低阳极溶解速度。钝化样品的耐腐蚀性因Fe氧化物（FeO和Fe ₂ O ₃）相对于FeOOH的相对浓度增加而受到青睐。