Heat-resistant austenitic steels as matrix materials for wear applications above 400°C

高温磨粒磨损的机理和影响因素不同于常温磨损。金属的高温性能要求有高温强度和高温硬度、塑性变形能力和硬化能力。在多相材料领域，这些要求主要适用于金属基体。材料高温磨损行为的稳定性主要取决于基体的性能。金属基体本身的耐磨性以及金属基体对硬质相的支撑和整合是相关的。奥氏体钢是可能的铁基基体材料，具有增加的耐高温磨损性。特别是具有低堆垛层错能（SFE）和低温度依赖性SFE增加的奥氏体钢对于高温磨料磨损应用是有利的。该研究项目的目标是将FeCrNi基合金的高温磨损的考虑扩展到间隙合金化元素、沉淀物和摩擦学诱导相变的作用。间隙元素C和N对奥氏体钢的力学性能有显著影响。通过生产和检测不同的单相FeCrNi（C）N合金，应研究C和N在高温下对金属物理和摩擦学性能的影响。此外，应详细阐述奥氏体钢沉淀硬化的概念，以进一步提高高温耐磨性。分散的沉淀物可以通过充当位错滑移的障碍物来阻碍位错运动，从而有助于材料的强化。为了证明沉淀硬化对磨损行为的影响，将开发允许碳化物、氮化物以及碳氮化物沉淀的FeCrNi（C）N基合金。高温磨损试验应阐明沉淀硬化对高温耐磨性的影响，以及对发生的磨损机制的影响。此外，变形引起的相变的奥氏体晶格中的摩擦影响区，被考虑在内。因此，应该研究在什么条件下发生的相变在磨料磨损和相变如何影响磨损behaviors.The项目的首要目标是获得的FeCrNi基合金的系统中的摩擦学行为的间隙合金元素和第二相的作用的基本理解，并开发一种合金的概念，是定制的高温磨料磨损。

The mechanisms and factors of high-temperature abrasive wear differ from those of ambient temperature wear. Required high-temperature properties of metals are high-temperature strength and hot-hardness, plastic deformability and hardening ability. These requirements apply, in the field of multiphase materials, primarily to the metal-matrix. The stability of a materials high-temperature wear behavior is mainly determined by the matrix properties. The wear resistance of the metal-matrix itself, as well as the support and integration of hard phases by the metal-matrix are relevant. Austenitic steels are possible Fe-based matrix-materials with increased resistance to high-temperature wear. Especially austenitic steels with a low stacking fault energy (SFE) and a low temperature-dependent increase of the SFE are advantageous for high-temperature abrasive wear applications. The ambition of this research project is to extend the consideration of high-temperature wear of FeCrNi-base alloys to the role of interstitial alloying elements, precipitates, and tribologically induced phase transformations. The interstitial elements C and N have a significant impact on the mechanical properties of austenitic steels. By producing and examining different single-phase FeCrNi(C)N-alloys, the influence of C and N on the metal physical and tribological properties at elevated temperatures should be investigated. In addition, concepts for the precipitation hardening of austenitic steels should be elaborated, to further increase the high-temperature wear resistance. Dispersed precipitates can hinder dislocation movement by acting as obstacles for dislocation slip and thereby contribute to the strengthening of the material. To prove the effect of precipitation hardening on the wear behavior, FeCrNi(C)N-base alloys that allow the precipitation of carbides, nitrides as well as carbonitrides, will be developed. High-temperature wear tests should then elucidate the influence of precipitation hardening on the high-temperature abrasive wear resistance, as well as on the occurring wear mechanisms. Furthermore, deformation-induced phase transformations of the austenitic lattice in the tribologically affected zone, are taken into account. Thereby it should be investigated under what conditions phase transformations occur during abrasive wear and how phase transformations influence the wear behavior.The overarching aim of the project is to gain fundamental understanding of the role of interstitial alloying elements and secondary phases on the tibological behavior in the system of FeCrNi-base alloys and to develop an alloy concept that is customized for high-temperature abrasive wear.