WEB The role of electric current in the formation of white-etching-cracksThursday (24.09.2020) 17:20 - 17:35 S: Structural Materials 1 Part of:
Material failure by white-etching-cracks (WECs) causes great economic costs. The formation of white etching cracks (WECs) goes along with the decomposition of the original, usually cementite-containing, microstructure. As small amounts of electric current can trigger this failure mechanism , we investigate the contribution of electric current to cementite decomposition. We applied ~700 A/cm^2 for two weeks at 60°C to a pearlitic Fe-0.74C (wt%) specimen. The comparison of the microstructure before and after showed no differences. Theoretical considerations support the conclusion that such low electric current densities cannot directly cause cementite decomposition at this low temperature. Electric current must play an indirect role in the formation of WECs, supposedly, by generating hydrogen from the lubricant which is known to accelerate WEC formation.
 J. Loos, I. Bergmann, M. Goss, Influence of Currents from Electrostatic Charges on WEC Formation in Rolling Bearings, Tribology Transactions, 59 (2016) 865-875.