MAGNAFLUXING

Magnetic particle inspection is a nondestructive method used for detection of surface flaws in ferrous parts. An MPI inspection is used to inspect a variety of product forms such as castings, forgings, and weldments. MPI is performed by a magnetic field applied to the specimen, either locally or overall, using a permanent magnet, electromagnet, flexible cables or hand-held probes. If the material is sound, most of the magnetic flux is concentrated below the material’s surface. However, if a flaw is present, such that it interacts with the magnetic field, the flux is distorted locally and leaks from the surface of the specimen in the region of the flaw. Fine magnetic particles, applied to the surface of the specimen, are attracted to the area of flux leakage, creating a visible indication of the flaw. Inspecting roller shafts for defects is now part of the range of services provided by Electro-Coatings.