#ndt The braking process used on railroad cars is known to create tensile stresses in the circumferential direction due to the thermal expansion and subsequent cooling of the wheel rim. The presence of tensile residual stresses can contribute to, and are often the main cause of fatigue failure and cracking.

Compressive residual stresses are generally induced by different means in the wheel material during manufacturing process as these are beneficial since they prevent origination and propagation of fatigue c
Source: NDT