What is the method?
Magnetic Particle Inspection (MPI), or Magnetic Testing (MT), is used to detect surface and near-surface discontinuities in ferromagnetic materials. The component is magnetised and magnetic particles are applied. Discontinuities cause magnetic flux leakage, attracting the particles and producing visible indications.
Application
Magnetic Particle Inspection (MPI), or Magnetic Testing (MT), is used to detect surface and near-surface discontinuities in ferromagnetic materials. The component is magnetised and magnetic particles are applied. Discontinuities cause magnetic flux leakage, attracting the particles and producing visible indications.
Key Benefits
- Highly effective for surface and shallow subsurface flaw detection.
- Fast and practical for workshop and field inspection.
- Well suited to welds, repaired areas, and structural steelwork.
- Produces clear visible crack indications.
Inspection Capabilities
- Can detect discontinuities just below the visible surface, which DPI cannot reveal.
- Excellent for fatigue cracks, weld toe cracks, grinding cracks, and HAZ indications in ferromagnetic materials.
- Enables rapid inspection of long weld runs and large steel areas.
- Adaptable through use of yokes, prods, coils, and bench units.
Limitations
- Applicable only to ferromagnetic materials.
- Detectability depends on the orientation of the discontinuity relative to the magnetic field.
- Surface coatings and poor access may reduce sensitivity.
- Demagnetisation may be required after inspection.