Magnetic particle inspection is used for detecting surface and subsurface defects in objects of various shapes and sizes, made of ferromagnetic materials or objects with a nonmagnetic coating.
This inspection can reveal cracks of various origins , hairline and other imperfections opening width of a few micrometers.
Magnetic method has the following advantages:
high sensitivity ;
ease of control and the ability to test various shapes and sizes of parts on the same flaw ;
the ability to control parts which are in construction;
relatively high performance control.
Magnetic particle inspection process operations are conducted in the following sequence :
applying to the surface of the indicator ( powder or slurry) ;
inspection of parts ;
transcript pattern and grading of the indicator ;
demagnetization and control demagnetized ;
removal of residues from the part indicator.