Disadvantages of magnetic flux leakage detection of steel pipes

1. Only applicable to ferromagnetic materials. Because the step of magnetic flux leakage detection is magnetization, the magnetic permeability of the non-ferromagnetic material is close to 1, and the magnetic field around the defective part will not change in distribution due to different magnetic permeability, and no magnetic leakage will be generated.

2. Strictly speaking, magnetic flux leakage detection cannot detect defects inside ferromagnetic materials. If the defect is far away from the surface, the magnetic field distortion around the defect part mainly appears around the defect, and the leakage magnetic field may not appear on the surface of the work-piece.

3. Magnetic flux leakage testing is not applicable to test specimens with coating or covering on the surface.

4. Magnetic flux leakage testing is not applicable to test pieces with complex shapes. Magnetic leakage detection uses a sensor to collect magnetic flux leakage signals. The slightly complicated shape of the test piece is not conducive to detection.

5. Magnetic leakage detection is not suitable for detecting cracks with very narrow cracks, especially closed cracks.

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