Failure analysis of the repair procedure of an ore compactor roll

This paper deals with the failure analysis of a potassium ore compactor roll that experienced short term fracture in service after a repair procedure. The journal bearing of the shaft experienced wear after a long period in use. Afterwards, a surface deposition was performed in order to retrieve the roll functionality, but it culminated in the formation of radial cracks beginning just near the shaft curvature radius. This portion of the roll was then removed and replaced with a new shaft interference-fitted and welded into the roll. Moreover, after this new repair procedure, the roll experienced a short term fracture. Failure analyses were performed by liquid penetrant, fracture analysis, hardness testing and metallographic analysis. Numerical simulations were also carried out considering the last repair features. Fatigue failure nucleated near a singularity at the shaft curvature radius. This singularity was originated from the interference fit and welding procedures.