SURFACE TREATED ROLLING BEARING AND MANUFACTURING METHOD THEREOF

摘要

In the case of a rolling bearing used in an environment where water is likely to penetrate into a lubricant, such a phenomenon is known that hydrogen ions generated by the decomposition of the lubricant are adsorbed to the race surface to be turned into hydrogen atoms for accumulation in a high-strain location (in proximity of a maximum shearing stress position) to cause stress corrosion crack separation. A rolling bearing comprising an oxide film made of chromium iron oxide and 1 to 1000 nm thick which is formed on at least one of a race surface and the rolling surface of a rolling element and a method of manufacturing the rolling bearing, wherein the oxide film can prevent the penetration of hydrogen generated by the decomposition of water mixed in a lubricant into a bearing member matrix to prevent an early separation of the race surface or the rolling surface of a rolling element, thereby prolonging significantly a rolling life. The oxide film can be simply formed by tempering a bearing member and then heating it again in the air at temperatures lower than the tempering temperature.