Surface cracks in castings, forgings and welds often appear; however, they are not visible to the human eye. Cracks can cause major integrity problems
Applus+ RTD delivers MPI, the widely used NDT technique, for the detection and sizing (length not depth) of surface-breaking cracks in ferromagnetic materials. Flaws in components which break the surface, or which lie just (generally < 1 mm) beneath the surface, alter the magnetic flux field. This disturbance is greatest for flaws extending perpendicular to the flux lines, and large flaws can be detected even if they lie just below the surface.
MPI is a relatively simple, fast and low-cost method for surface inspection.