Accelerated White Etch Cracking (WEC) FE8 type tests of different bearing steels using ceramic rollers
Hilmar Kjartansson Danielsen, Francisco Gerardo Antonio Gutierrez Guzman, Søren Fæster, M. Shirani, Bjarke Rasmussen, Martin Linzmayer, Georg Jacobs
Abstract
White Etch Cracking (WEC) is a severe and unpredictable failure mode affecting bearings in various industrial sectors. In this work, accelerated WEC laboratory tests have been performed using FE8 type test rigs with ceramic rollers to test the WEC resistance of different bearing materials, materials quality and roughness. It is demonstrated that the test method can reliably and consistently provoke WEC in commercially available washers. Tests using washers with different roughness values did not show significant changes in the time to failure. Tests of through hardened bearing steel with a low content of inclusions resulted in a significantly longer time to failure compared to the baseline. Through hardened washers with a black oxide coating did not improve the WEC life as the coating was worn away during testing. Tests with two types of carbo-nitrided washers gave significantly longer time to failure, of which one type in particular showed high resistance towards WEC formation.