Does magnetic particle testing work on stainless steel?
Stainless steel can’t be inspected by magnetic particle testing as we aren’t able to induce a magnetic field on the stainless steel. Due to this, the material remains non-magnetic. Ferritic stainless steels are actually ferromagnetic.
What equipment is used in magnetic particle inspection?
The MPI test bar is a standardized test piece that can be used with wet bench magnetic particle equipment, power pack coil wraps, or magnetic yokes. The test bar has both surface and sub-surface flaws for use with AC, HWDC, FWDC, and 3-phase FWDC magnetizing equipment.
What is MPI machine?
Magnetic Particle Inspection (MPI) is a non-destructive testing method that can detect surface and subsurface flaws in ferromagnetic materials. The method can detect surface or near-surface flaws such as cracks, laps, seams and inclusions in ferromagnetic materials such as iron and steel.
How do you test MPI?
Magnetic Particle Inspection is performed in four steps:
- Induce a magnetic field in the specimen.
- Apply magnetic particles to the specimen’s surface.
- View the surface, looking for particle groupings that are caused by defects.
- Demagnetize and clean the specimen.
What method of magnetic particle inspection is used most often?
What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks and other defects? Continuous.
Where is magnetic particle testing used?
This method is used for the detection of surface and near-surface flaws in ferromagnetic materials and is primarily used for crack detection. The specimen is magnetised either locally or overall, and if the material is sound the magnetic flux is predominantly inside the material.
What is the advantage of using DC in MPI?
| Current Type | Advantages |
|---|---|
| Direct Current (DC) -from DC generators and storage batteries | greater depth of penetration detects defects wholly below the surface field is uniform over part’s cross-section |
| Half Wave Direct Current (HWDC) single phase-from rectified AC sources | detects subsurface defects improved particle mobility |
Which material Cannot be tested by MPI?
Explanation: Magnesium (Mg) is a non-magnegnetic material. So, it can’t be tested by magnetic particle inspection. Whereas Cobalt (Co), iron (Fe) and Nickel (Ni) are ferromagnetic materials.
What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks?
Aircraft Maintenance NDT Principles
| Question | Answer |
|---|---|
| A part which is being prepared for dye penetrant inspection should be cleaned with… | A volatile petroleum base solvent |
| What method of magnetic particle inspection is used most often to inspect aircraft parts for invisible cracks and other defects? | Continuous |
What type of crack can be detected by magnetic particle inspection?
One way to a part may be demagnetized after magnetic particle inspection is by.. slowly moving the part out of an ac magnetic field of sufficient strength. Which type crack can be detected by magnetic particle inspection using either circular or longitudinal magnetization? 45 degrees.
What are the limitations of magnetic particle testing?
Disadvantages of the Magnetic Particle method of Non-Destructive Examination are:
- It is restricted to ferromagnetic materials – usually iron and steel, and cannot be used on austenitic stainless steel.
- It is messy.
- Most methods need a supply of electricity.
Which is the best test for austenitic stainless steel?
Austenitic stainless steel can be tested by nondestructive testing using the dye penetrant inspection method but not the magnetic particle inspection method. Eddy-current testing may also be used.
What kind of test is magnetic particle inspection?
Magnetic Particle Testing (MT) (also known as magnetic particle inspection – MPI) is a non destructive test (NDT) method, used to detect surface or subsurface (near to surface) discontinuities. This NDT method can be used on metals which can be easily magnetized (ferromagnetic).
What are the mechanical properties of austenitic stainless steel?
Alloy 20 has excellent mechanical properties and the presence of niobium in the alloy minimizes the precipitation of carbides during welding. Austenitic stainless steel can be tested by nondestructive testing using the dye penetrant inspection method but not the magnetic particle inspection method. Eddy-current testing may also be used.
Which is the best stainless steel for MPI inspection?
MPI can be carried out Stainless Steel – except Austenitic Stainless Steel example: SS 316, SS 304, SS 904L . For efficient defect detection MPI should be done in two different directions. Perpendicular to each other, or two magnetic field longitudinal and Circular magnetic field both should be involved.