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

• Applicant: Professor Dr.-Ing. Werner Theisen
• Subject Area: Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2016 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 319959745

• Final Report Year: 2023

Final Report Abstract

High-temperature abrasive wear is a distinct type of wear in metallic materials that differs from room temperature wear mechanisms due to the influence of temperature on material properties. Compared to abrasion at room temperature, high-temperature abrasive wear requires higher thermal strength, hardness, plastic deformability, and strain hardening ability of the materials. These requirements primarily pertain to the metal matrix, as the matrix properties determine the stable wear behavior of the material. In this research project, an approach was pursued that combines investigations of mechanisms responsible for higher thermal strength with examinations of the mechanisms and influencing factors of high-temperature abrasive wear. The goal was to correlate temperature-dependent changes in tribological properties with the microstructure and utilize the findings for further optimization of materials resistant to high-temperature wear. Furthermore, within the scope of this research project, the influence of microstructure on thermophysical properties has been analyzed. The increased tendency for stacking faults formation at elevated temperatures was expected to contribute to enhanced resistance against thermal softening due to lower stacking fault energy. The stacking fault energy can be intentionally influenced by the alloy composition. Stacking faults, stacking fault energies, and related microstructural processes were examined through thermodynamic equilibrium calculations, X-ray diffraction, and microscopic investigations. In-situ experiments enabled direct observations of microstructural reactions to high-temperature abrasive wear. Complementary high-temperature wear experiments provided insights into the influences of the matrix material on the magnitude and mechanisms of high-temperature abrasive wear. Based on the insights gained and thermodynamic calculations, an alloy system has been developed that is optimized in terms of high-temperature stacking fault energy. The investigations and characterizations of the alloy system within the research project have demonstrated that a material optimized for high-temperature stacking fault energy also exhibits improved resistance against high-temperature abrasion.

Publications

• Investigation of the Tribological Behaviour of HS6-5-3 type Tool Steels during High-Temperature Sliding Wear*. HTM Journal of Heat Treatment and Materials, 72(2), 105-114.
  Walter, M.; Egels, G.; Boes, J.; Röttger, A. & Theisen, W.
  
• Mechanisms of severe sliding abrasion of single phase steels at elevated temperatures: Influence of lattice structure and microstructural parameters. Wear, 376-377, 468-483.
  Walter, M.; Weber, S.; Boes, J.; Egels, G. & Theisen, W.
  
• Investigation of austenitic FeCrNi steels with regard to stacking-fault energy and thermal austenite stability. Materialia, 3, 265-273.
  Fussik, R.; Walter, M.; Theisen, W. & Weber, S.
  
• Subsurface characterization of high-strength high-interstitial austenitic steels after impact wear. Wear, 402-403, 137-147.
  Mujica, Roncery L.; Agudo, Jácome L.; Aghajani, A.; Theisen, W. & Weber, S.
  
• Influence of Hot Hardness and Microstructure of High‐Alloyed Powder Metallurgical Tool Steels on Abrasive Wear Behavior at Elevated Temperatures. steel research international, 91(5).
  Wulbieter, Nils; Pöhl, Fabian & Theisen, Werner
  
• On the evolution of dislocation cell structures in two Al-alloys (Al-5Mg and Al-11Zn) during reciprocal sliding wear at high homologous temperatures. Wear, 418-419, 1-12.
  Parsa, A.B.; Walter, M.; Theisen, W.; Bürger, D. & Eggeler, G.
  
• A Comparative Study on the Tribological Properties of a Cobalt-Free Superaustenitic Stainless Steel at Elevated Temperature. Metals, 10(9), 1123.
  van gen Hassend, Frederic & Weber, Sebastian
  
• XRD measurement of stacking fault energy of Cr–Ni austenitic steels: influence of temperature and alloying elements. Journal of Materials Science, 55(27), 13424-13437.
  Walter, M.; Mujica, Roncery L.; Weber, S.; Leich, L. & Theisen, W.
  
• Hot Wear of Single Phase fcc Materials—Influence of Temperature, Alloy Composition and Stacking Fault Energy. Metals, 11(12), 2062.
  Berger, Aaron; Walter, Maximilian; Benito, Santiago Manuel & Weber, Sebastian
  
• Impact of Thermophysical Properties of High-Alloy Tool Steels on Their Performance in Re-Purposing Applications. Materials, 15(23), 8702.
  Berger, Aaron; Benito, Santiago; Kronenberg, Philipp & Weber, Sebastian
  
• Repurpose – How to upgrade tools and save resources. Cleaner Waste Systems, 6, 100114.
  Kronenberg, P.; Hagedorn, W.; Berger, A.; Hellwig, F.; Wieczorek, L.; Jäger, S.; Weber, S. & Röttger, A.