Magnetic Particle Permanent Magnet Inspection
Magnetic particle permanent magnet testing uses strong permanent magnets to create a test magnetic field and attract magnetic particles to reveal cracks or defects in welds. This method is mains-independent and suitable for on-site inspections.
Physical-Chemical Mechanism of Action
This test uses the property of permanent magnets to generate a stable magnetic field. This field magnetizes the metal in the weld, so that magnetic powder gathers at cracks or defects and becomes visible.
Metallurgical Relevance & Welding Risks
This method is especially useful for inspecting welds in hard-to-reach areas or where no power supply is available. It can reveal cracks and defects that other testing methods might miss. However, one risk is that the quality of the inspection depends on the strength of the permanent magnet and the application method.
Workshop Practice & Instructions
To perform a successful test, follow these steps:
1. Prepare the weld by making it clean and free of dust.
2. Apply the magnetic powder to the weld area.
3. Hold the permanent magnet over the powder and move it slowly along the weld.
4. Watch for powder gathering at cracks or defects and document the results.