Abstract
Herein, the abrasive wear behavior of different high‐alloyed powder metallurgical (PM) tool steels is investigated at elevated temperatures (400–600 °C) in a dry‐pot wear tester containing Al2O3 particles. To identify the influence of the microstructure, PM tool steels with different hot hardnesses, carbide types, and carbide volume contents are selected. Wear tracks are analyzed by scanning electron microscopy (SEM) to clarify wear mechanisms. The results show that there is no direct correlation between wear resistance and only one material property such as hot hardness, carbide content, or carbide type. More important seems to be the best possible compromise between a sufficient hot hardness of the metallic matrix and a high volume content of carbides that are harder than the attacking abrasive particles at the respective temperature. When the test temperatures surpass the tempering temperature of the investigated steels, there is a pronounced change in wear behavior due to the stronger embedding of abrasive particles into the wear surface. It is thus necessary to discuss the microstructural properties as a function of temperature, considering interactions with the abrasive particles.
Highlights
These microstructural requirements can be achieved with alloys manufactured by powder metallurgy
According to Berns et al, the following general rules should be considered for highly wear-resistant alloys at elevated temperatures[1,2,3]: 1) The hot hardness of the material should be greater than that of the attacking abrasive particles (e.g., SiO2, Al2O3). 2) To achieve tance, they have high compressive and bending strengths, high toughness, and simplified machinability compared with white cast iron or hard-facing alloys.[3,4]
This study investigated the abrasive wear behavior at elevated temperatures of two highly alloyed powder metallurgical (PM) cold work tool steels and two PM high-speed steels using a special abrasion test machine against corundum (Al2O3) particles
Summary
These microstructural requirements can be achieved with alloys manufactured by powder metallurgy. Applications in which tools are simultaneously exposed to abrasive wear and high temperatures, e.g., in the steelmaking industry or raw materials processing industry, place special requirements on the microstructure of tool materials. According to Berns et al, the following general rules should be considered for highly wear-resistant alloys at elevated temperatures[1,2,3]: 1) The hot hardness of the material should be greater than that of the attacking abrasive particles (e.g., SiO2, Al2O3). 2) To achieve tance, they have high compressive and bending strengths, high toughness, and simplified machinability compared with white cast iron or hard-facing alloys.[3,4] Tool steels can be divided into cold work (CWS), hot work (HWS), and high-speed tool steels (HSS).[5,6] In principle, the use of HSS is recommended for abrasive wear at high temperatures. HSS exhibit a high hardness up to temperatures of 600 C due to precipitation hardening by fine secondary carbides after quenching and multiple tempering steps.[5,6,8] These secondary carbides are of type M2C and MC and precipitate from the metal matrix in the tempering range of %450–600 C.[9,10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
