Magnetic particle inspection ensures that parts are free of fatigue stress, structural defects, or stress cracks. The technology, which can be applied to existing, in-use parts, or newly manufactured parts and components that require integrity testing, has been around for more than a century.
When in doubt, always check with a certified Level III or contact your NDT product supplier.
June 9, 2021
Generations of NDT professionals have used the magnetic testing method, and along the way, a handful of common misunderstandings have developed. This article explores these common and incorrect assumptions about magnetic particle inspection and how to combat these misunderstandings.
The conventional measurement of mechanical hardness, for instance, in steel, is usually carried out using the same principle. A mechanical indenter is forced towards the surface of the workpiece, penetrating it and leaving an imprint.
It is true that magnetic particle testing (MT) is one of the oldest NDT methods, and over the years has proven itself to be not only reliable, but cost effective, when it is applied properly with qualified personnel.
Each day, facilities across the globe turn to nondestructive testing (NDT) to verify the reliability of parts or materials without causing damage. One of the most popular of these methods is magnetic particle inspection (MPI)—a form of NDT that uses magnetism to detect surface and near-surface defects, cracks, seams or stress points in ferromagnetic materials before parts and materials are placed into service.
On April 20, three days after a Southwest Airlines Boeing 737-700 experienced an engine failure due to a fractured fan blade, resulting in the death of a passenger, the U.S. Federal Aviation Administration issued an emergency airworthiness directive that requires operators of CFM56-7B engines with more than 30,000 flight cycles to perform a one-time ultrasonic inspection of all 24 fan blades to detect cracking.