INTRODUCTION TO MAGNETIC PARTICLE INSPECTION.

Magnetic particle inspection (MPI) is a nondestructive testing method used for defect detection MPI is fast and relatively easy to apply, and part surface preparation is not as critical as it is some other NDT methods. These characteristics make MPI one of the most widely utilized nondestructive testing methods.
MPI uses magnetic field and small magnetic particle (I.e.iron filings) to detect flaws in component. The only requirement from inspectability standpoint is that the component being must be made of a ferromagnetic material such as iron, nickel, or some of their alloys. Ferromagnetic materials are materials that can be magnetized to a level that will allow the inspection to be affective.
The method is used to inspect a variety of product including castings,forgings,and weldments. Many different industries use magnetic particle inspection for determining a components fitness - for - use. Some examples of industries that use magnetic particle inspection are the structural steel, automotive, petrochemical, power generation, and aerospace industries. Underwater inspection is another area where magnetic particle inspection may be used to test items such offshore structure and underwater pipelines.