Parts exposed to wear and corrosion under high temperature are often made of Co-Cr-C alloys, known as Stellite alloys. The basic element Co contributes to the great thermo-mechanical properties of this alloy group. Unfortunately, the use of Co is not without disadvantages. Co is classified by the European Union as a critical element, because of its great importance for industry and the limited and potentially unstable supply situation. Furthermore, the mechanical machining of Co is accompanied by the formation of carcinogen byproducts. Therefore, huge socio-economic and regulatory driving forces to lower the amount of Co in metal alloys exist.
This works investigates the possibility to substitute Co in a Co-Cr-W-C alloy (Stellite 6) by Fe. For this purpose, several alloys with varying Fe-content were fabricated by casting. The microstructure of these specimen is characterized. The hot-hardness is measured in the temperature range from room temperature (RT) to 800 °C by Vickers hardness indentation tests and the results compared to the hot hardness of common Stellite 6. Stellite alloys are known to exhibit a high resistance in sliding wear, because of low friction coefficients. To assess the effect of iron on the wear resistance of Stellite 6 alloy, wear and friction tests of selected specimen are carried out at RT, 400°C and 700 °C.