Abstract In this study, the morphological, structural and chemical changes during friction loading of a metastable fully austenitic TWIP steel and of a case-hardened carburized 16MnCr5 steel were investigated by various methods. To do so, EFTEM imaging, SAD, TEM-XEDS, TEM-EELS, XRD, EBSD, and ACOM-TEM were applied for the unloaded state and after defined friction loading. Although the investigated materials appeared very different in their unloaded states concerning their phase compositions, grain sizes and mechanical properties, the friction loading led to significant, but comparable changes in both materials. These changes start immediately from the worn surface and continue towards the sample depth. An extremely fine-grained nanocrystalline surface layer with a thickness of several hundred nanometers and a nanocrystalline sub-surface layer were formed with sharp interfaces between them. The grain size remains nearly constant within the first layer, but increased immediately crossing the interface between these layers and gradually enlarges further within the sub-surface layer with increasing distance to the interface. These layers differ tremendously from the unloaded states and were characterized in a detailed way. Explanations for the formation of these layers were supposed.

中文翻译：

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摩擦载荷引起的高锰 TWIP 钢和表面硬化 16MnCr5 的显微组织变化

摘要 在这项研究中，通过各种方法研究了亚稳态全奥氏体 TWIP 钢和表面硬化渗碳 16MnCr5 钢在摩擦载荷过程中的形态、结构和化学变化。为此，将 EFTEM 成像、SAD、TEM-XEDS、TEM-EELS、XRD、EBSD 和 ACOM-TEM 应用于未加载状态和定义的摩擦载荷之后。尽管所研究的材料在其相组成、晶粒尺寸和机械性能方面在未加载状态下表现出非常不同，但摩擦载荷导致两种材料发生显着但具有可比性的变化。这些变化立即从磨损表面开始，并继续朝着样品深度方向发展。形成了具有数百纳米厚度的极细晶粒纳米晶表面层和纳米晶亚表面层，它们之间具有尖锐的界面。晶粒尺寸在第一层内几乎保持不变，但在穿过这些层之间的界面时立即增加，并随着与界面距离的增加而在次表层内逐渐扩大。这些层与卸载状态有很大不同，并以详细的方式进行了表征。假设对这些层的形成进行了解释。但越过这些层之间的界面立即增加，并随着与界面距离的增加而在次表层内进一步扩大。这些层与卸载状态有很大不同，并以详细的方式进行了表征。假设对这些层的形成进行了解释。但越过这些层之间的界面立即增加，并随着与界面距离的增加而在次表层内进一步扩大。这些层与卸载状态有很大不同，并以详细的方式进行了表征。假设对这些层的形成进行了解释。