Scanning Induction Thermography for Bearing Ring Under AC-DC Composite Magnetization

Induction thermography is a promising nondestructive testing technique with the advantages of high efficiency, lift-off tolerance, and defect imaging. To fulfill scanning detection quantify in bearing rings, this paper proposes eddy current under AC-DC composite magnetization. With DC magnetization, will cause permeability disturbance ring surface. Under high-frequency AC disturbed generate non-uniform thermal response captured by infrared camera. investigate principle, multi-physics coupling simulation model for distribution process built, involving DC-AC nonlinear ferromagnetic material, heat generation, conduction, movement. Then, data post-processing method imaging crack quantification proposed. Finally, induction system rings designed developed. The experimental results show that proposed can cracks depths up to 2.0 mm.