Preliminary study - Materials and heat treatment as countermeasures against white etching areas/white etching cracks
Preliminary study - Materials and heat treatment as countermeasures against white etching areas/white etching cracksCopyright: © MSE
White Etching Areas" and "White Etching Cracks" (WEA/WEC) have been identified as significant elements in the causal chain of premature rolling bearing damage between 1 and 20% of the calculated life (L10). Due to the high economic relevance, the occurrence of WEA/WEC is currently discussed in a considerable amount of literature. Based on this intensive research work, it has already been possible to identify factors that favor the formation of WEA/WEC. These include the contact conditions, stress condition, lubricant, material, hydrogen as well as electric current and temperature.
In practice, however, it has not yet been possible to derive any proven economic measures for the avoidance of WEA/WEC. Current research efforts to avoid WEA/WEC focus on the description of the material influence on the formation of WEA/WEC. The field of materials and heat treatments offers a wide range of scientifically possible solutions, which are, however, strongly limited by economic and competitive constraints.
The aim of this study was to identify material engineering solutions to prevent WEA/WEC in rolling bearings, considering the above-mentioned boundary conditions. These material countermeasures were to be summarized and evaluated in order to enable recommendations for targeted research in follow-up projects.
In order to achieve this goal, the literature was first reviewed. In addition to the various materials, heat treatments and coatings were also considered. The most important 73 sources were identified from more than 1200 pieces of literature and the main countermeasures were summarized. In the following step, expert consultations were carried out in the form of interviews and a survey. The purpose of the expert consultations was a systematic reduction of the extensive and heterogeneous results of the literature research as well as an initial potential assessment of countermeasures with regard to practical relevance and research requirements.
The potential countermeasures were then evaluated in a feasibility study in the form of a corresponding half-day industry workshop.
Research and Project Partners
- IWM – Chair and Institute for Materials Applications in Mechanical Engineering
- GFE – Central Facility for Electron Microscopy, RWTH-Aachen University