Correlation of Magnetic Perturbation Inspection Data With Rolling-Element Bearing Fatigue Results

Abstract

A magnetic perturbation technique was used to nondestructively detect subsurface non-metallic inclusions in the inner races of 207-size, deep groove ball bearings. The bearings were fatigue tested at 2750 rpm under a radial load of 5860 newtons (1320 lb). The inner races were subsequently sectioned at fatigue spall locations and at magnetic perturbation signal locations. Analyses of the data indicated good correlation between magnetic perturbation signals and inclusion size and location. Exclusion of those bearings that had significant magnetic perturbation signals did not alter the statistical life of the bearings.