Low alloy steel faces localized corrosion issues in service environments, primarily due to pitting corrosion induced by inclusions. Conventional protective measures cannot significantly improve the corrosion resistance of the steel. In this study, an effective industrial approach was proposed to enhance the corrosion resistance of low alloy steels. Cerium (Ce) was added during the refining process to modify inclusions and alter the mechanism of inclusion-induced localized corrosion, thereby improving the substrate’s ability to inhibit pitting corrosion. The effect of Ce treatment on the cleanliness of molten steel was investigated, and a kinetic model of inclusion evolution was established based on thermodynamic calculations. The pitting corrosion induced by CaS·C₁₂A₇ and CeAlO₃ inclusions was studied through immersion experiments over different durations. The degree of corrosion after being soaked for 20 min was significantly different. The size and depth of pitting pits induced by CeAlO₃ inclusions were much smaller than those induced by CaS·C₁₂A₇ inclusions. The electron back scatter diffraction tests confirmed that CaS·C₁₂A₇ inclusions exhibited a higher corrosion sensitivity compared to CeAlO₃, thus promoting the initiation of pitting. Electrochemical tests demonstrated a positive shift in the corrosion potential and a reduction in current density. This implies that CeAlO₃ inclusions can significantly inhibit pitting occurrences. Based on the dissolution behaviors of CaS·C₁₂A₇ and CeAlO₃ inclusions, a kinetic model was established to describe the initiation and propagation of pitting induced by these inclusions.

中文翻译：

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揭示Ce对低合金钢夹杂物诱导点蚀的影响：CaS·C12A7 和 CeAlO3 的抑制


低合金钢在服务环境中面临局部腐蚀问题，主要是由于夹杂物引起的点蚀。传统的保护措施无法显著提高钢材的耐腐蚀性。在本研究中，提出了一种有效的工业化方法来提高低合金钢的耐腐蚀性。在精炼过程中添加铈 （Ce） 以修饰夹杂物并改变夹杂物诱导的局部腐蚀机制，从而提高基材抑制点蚀的能力。研究了 Ce 处理对钢水清洁度的影响，并基于热力学计算建立了夹杂物演化动力学模型。The pitting corrosion induced by CaS·通过不同持续时间的浸泡实验研究了 C₁₂A₇ 和 CeAlO₃ 夹杂物。浸泡 20 min 后腐蚀程度差异显著。CeAlO₃ 包裹体诱导的点蚀坑的大小和深度远小于 CaS·C₁₂A₇ 内含物。电子背散射衍射测试证实，CaS·与 CeAlO₃ 相比，C₁₂A₇ 夹杂物表现出更高的腐蚀敏感性，从而促进了点蚀的开始。电化学测试表明腐蚀电位发生正向变化，电流密度降低。这意味着 CeAlO₃ 夹杂物可以显著抑制点蚀的发生。基于 CaS·C₁₂A₇ 和 CeAlO₃ 包裹体，建立了一个动力学模型来描述这些包裹体诱导的点蚀的开始和传播。