What should be done if a part shows residual magnetism after MPI?

When a part exhibits residual magnetism following a Magnetic Particle Inspection (MPI), it is essential to demagnetize the part correctly. Residual magnetism can interfere with subsequent inspections and may lead to incorrect assessments of the part's integrity. Demagnetization ensures that the magnetic field does not attract magnetic particles inappropriately, which could hide defects or create false indications during future tests.

Demagnetizing the part eliminates any unwanted magnetic fields, restoring the part to a non-magnetic state, thereby allowing a more accurate inspection if it needs to be evaluated again. This process is crucial in ensuring the reliability of the components, particularly in applications where high safety standards are necessary.

In contrast, allowing the part to remain untreated could lead to issues in its performance or safety, applying an additional magnetic field would exacerbate the issue rather than resolve it, and inspecting the part again immediately without addressing the residual magnetism would not yield valid results due to the interference caused by that magnetism.