Railway wheel failure caused by flange crack, part 1: Background and failure analysis

A technical investigation is carried out on a railway wheel failure caused by a fatigue crack initiated at the inside of the flange. When the crack reached a critical size it propagated into the hub causing loss of grip on the axle and a shift inwards along the axle. Continued operations with the displaced wheel caused damage to 15 km of track. The cracked wheel was at the end of its service life with wheel diameter and flange thickness close to limit values. Material testing shows requirements to be fulfilled. Fractographic and metallographic analyses establish how the final fracture progressed from initiation at the flange. The conclusions drawn in the current study provide input to a subsequent investigation of load conditions causing the failure which is presented in the second part of this paper [1] .