High manganese steel is influenced by the combined effects of corrosion and wear during service under specific conditions, resulting in components with shortened service life. Under harsh service environments, newly developed Cr+N alloyed austenitic high manganese steel (Mn18Cr7C0.6N0.2 steel) as a new type of railway steel has shown promising results. Herein, the tribocorrosion behaviors of Mn18Cr7C0.6N0.2 and Mn13C1.1 steels in artificial acid rain were studied using electrochemical methods, field emission scanning electron microscope (FE-SEM), focused ion beam scanning electron microscopy (FIB-SEM), scanning transmission electron microscopemicroscopy energy dispersive X-ray spectroscopy (STEM-EDS), and high resolution transmission electron microscopy (HR-TEM). The results showed the formation of passive film and gradient-nanostructure on surfaces of both test steels during tribocorrosion. A dense and tightly adhering amorphous passive film was formed on Mn18Cr7C0.6N0.2 steel surface with a superior blocking effect toward invasive ions. The high strain resistance and plasticity of the Mn18Cr7C0.6N0.2 steel resulted in an intact gradient-nanostructure, suitable for obtaining high surface hardness and maintaining the toughness of the matrix, contribute to providing high wear resistance. The oxide film on the Mn13C1.1 steel surface comprised crystal α-FeOOH. Vortex cracks formed in its gradient structure due to strain localization. Meanwhile, the relatively poor corrosion protection ability and vortex cracks of its gradient-nanostructure prevented it from maintaining interface integrity of the gradient nanostructure, resulting in inferior tribocorrosion resistance. In artificial acid rain, the new type of Cr+N alloyed Mn18Cr7C0.6N0.2 steel exhibited higher tribocorrosion resistance than traditional high manganese steel, promising for use as an excellent wear-resistant material under corrosive environments.

中文翻译：

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梯度纳米结构和极薄非晶钝化膜对新型Cr+N合金高锰奥氏体钢摩擦腐蚀行为的关键作用

高锰钢在特定条件下使用过程中，会受到腐蚀和磨损的综合影响，导致部件的使用寿命缩短。在恶劣的使用环境下，新开发的Cr+N合金奥氏体高锰钢（Mn18Cr7C0.6N0.2钢）作为新型铁路用钢已显示出可喜的效果。采用电化学方法、场发射扫描电子显微镜(FE-SEM)、聚焦离子束扫描电子显微镜(FIB-SEM)、扫描电镜等手段研究了Mn18Cr7C0.6N0.2和Mn13C1.1钢在人工酸雨中的摩擦腐蚀行为。透射电子显微镜显微镜能量色散 X 射线光谱 (STEM-EDS) 和高分辨率透射电子显微镜 (HR-TEM)。结果表明，在摩擦腐蚀过程中，两种试验钢的表面均形成了钝化膜和梯度纳米结构。 Mn18Cr7C0.6N0.2钢表面形成一层致密、紧密附着的非晶态钝化膜，对离子的侵入具有良好的阻挡作用。 Mn18Cr7C0.6N0.2钢的高应变抗力和塑性导致了完整的梯度纳米结构，适合获得高表面硬度并保持基体的韧性，有助于提供高耐磨性。 Mn13C1.1钢表面氧化膜由α-FeO​​OH晶体组成。由于应变局部化，其梯度结构中形成涡旋裂纹。同时，其梯度纳米结构的腐蚀防护能力较差，且存在涡流裂纹，无法保持梯度纳米结构界面的完整性，导致耐摩擦腐蚀性能较差。在人工酸雨中，新型Cr+N合金Mn18Cr7C0.6N0.2钢比传统高锰钢表现出更高的耐摩擦腐蚀性能，有望成为腐蚀环境下优异的耐磨材料。