Demagnetization
Demagnetization removes residual magnetism from parts after magnetic particle testing to avoid affecting subsequent machining steps like welding or cutting.
Physicochemical Mechanism of Action
Demagnetization reduces the magnetic field in parts to zero by applying a strong external magnetic field. This neutralizes the residual magnetism that was induced during magnetic particle testing.
Metallurgical Relevance & Risks in Welding
If residual magnetism is not removed, it can cause stress in the weld, leading to cracks and distortion in the part. This can affect the mechanical properties of the material and compromise safety.
Workshop Practice & Instructions
Use a demagnetizer with a strong external magnetic field that completely surrounds the part. The demagnetization process typically takes 1-2 minutes. Ensure that all parts are fully and uniformly demagnetized before further processing.