Occurrence Condition of Electric Current Density in Electrical Pitting

(In Case of Ball Bearing 608 for Application of Direct Current)

Abstract

Recently, several problems owing to electrical pitting have been observed to be extremely common in small bearings. Many researchers reported on the electrical pitting of bearings used for railcars. This paper deals with a fundamental experiment for electrical pitting in a small bearing (608). Experiments lasting 500 hours with conducting direct current between balls and raceways made it clear that the electrical pitting occurred at an electrical current density of about 0.04A/mm². This electrical current density was very small compared with that considered in conventional research.