What is the primary purpose of magnetizing a part before conducting a magnetic particle inspection?

The primary purpose of magnetizing a part before conducting a magnetic particle inspection is to create a magnetic field for particle attraction. This magnetic field is crucial because it enables the ferromagnetic particles to cluster at surface and near-surface discontinuities, such as cracks or voids, within the material. When the part is magnetized, the iron particles used during the inspection will respond to the magnetic field, highlighting these defects effectively.

Without this magnetic field, the particles would not adhere to the defects, making it difficult to identify any issues with the integrity of the part. Thus, magnetic particle inspection relies fundamentally on the interaction of the magnetic field and the properties of ferromagnetic materials to reveal subsurface problems, making this step essential for accurate inspection results.