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  foton@fotonndt.com   0232 376 92 01

Magnetic Particle Testing (MT)

   Magnetic Particle Testing (MT) is a nondestructive testing (NDT) technique for detecting surface and shallow subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys.

Scientific Explanation
   To identify a leak, ferrous particles, either dry or in a wet suspension, are applied to a part. These are attracted to an area of flux leakage and form what is known an indication which is evaluated to determine its nature, cause, and course of action, if any.
Application Areas
   Can be applied to all materials that are ferromagnetic.
Limitations
   Can not be applied to non-ferromagnetic materials. Does not work if area where the place of to applying discontinuity is not on correct degree. For big testing pieces, can be necessary high magnetic flux. Very roughness inspection surfaces are adversely affects the result of inspection. If there is paint or coating on the inspection surface, the thickness directly affects the result. 

Inspection

  1. Part is cleaned of oil and other contaminants.
  2. Necessary calculations done to know the amount of current required to magnetize the part.
  3. The magnetizing pulse is applied for 0.5 seconds, during which the operator washes the part with the particle, stopping before the magnetic pulse is completed.
  4. Spraying ferromagnetic particles to the surface.
  5. Cutting of the magnetizing current.
  6. Examination.
  7. Evaluation and report preparation.
  8. Demagnetising and cleaning the components.
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