Analysis of the causes of failure of the outer ring of a case-hardened steel tapered roller bearing
2026-06-18
The outer ring of a tapered roller bearing made of case-hardened steel G20CrNi2Mo suffered cracking during operation. Since this bearing is produced in large quantities and is used in critical components, in order to avoid the recurrence of similar cracking, it is necessary to identify the causes of its destruction. In this article, based on macroanalysis, microanalysis and scanning electron microscopy analysis, the causes of cracking are considered.
Macroscopic evidence of outer ring cracking
On the outer surface of the failed outer ring of a case-hardened steel tapered roller bearing, in addition to one through crack parallel to the axis, there are also two diverging thin cracks originating from a large crack. In addition to the non-working zones on both ends and in the middle part, there are two large wear zones on the ring, which are various shiny white stripes. From the edge of the wear zone, located approximately 20 mm from the end, a series of small straight cracks of the “scale” type begin, the direction of which is parallel to the large crack; the longest ones are about 40 mm, most are 5–10 mm, as shown in Fig. 1 and fig. 2. These signs indicate that a large through crack was formed as a result of the development of one of these small cracks.
