Abstract
For the drawbacks of present MFL (magnetic flux leakage) testing of omni-directional defects using multidirectional magnetization, a new method of MFL inspection for omni-direction defects under a unidirectional magnetization is proposed. Then, its feasibility is verified by simulations and experiments, leading to a breakthrough of the conventional MFL theory which argues that there is little MFL produced by the defects parallel or nearly parallel to the magnetization direction. Additionally, a method for ensuring a uniform evaluation for the defects with same sizes but different directions is also presented. Finally, some good application cases of the proposed technology were shown.