Magnetic particle Inspection (MPI) is a nondestructive testing (NDT) process for detecting surface and shallow subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys. The process puts a magnetic field into the part.

How is magnetic particle testing done?

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 is the basic principle of magnetic particle testing?

The principle of the method is that the specimen is magnetised to produce magnetic lines of force, or flux, in the material. If these lines of force meet a discontinuity, such as a crack, secondary magnetic poles are created at the faces of the crack.

What is MPI testing machine?

Magnaflux magnetic particle inspection (MPI) testing equipment is designed to be fast, reliable and high-value. Find out more about how Magnaflux inspection equipment is designed to find indications and defects like fatigue cracks in ferrous materials through wet or dry method mag particle testing.

What are the five steps involved in performing a magnetic particle inspection?

Steps for Magnetic Particle Inspection

• Surface Preparation:
• Inducing a Magnetic Field:
• Applying Magnetic Particles on the Test Surface:
• Examine the component surface for defects.
• Repeat the test by changing the magnetic field.
• Demagnetization and Cleaning:

Where is magnetic particle testing used?

Magnetic Particle Inspection (MPI) is a non-destructive testing method that can detect surface and subsurface flaws in ferromagnetic materials. Magnetic particle inspection is often carried out to help determine an item’s fitness for use or conformity.

Why 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.

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. 10.

What are the most important step in magnetic particle inspection?

Inducing a Magnetic Field: This is the most important step in the magnetic particle inspection procedure. In this step, place the equipment on the area to be tested and induce a magnetic field. Various types of magnetic particle inspection equipment are available.

What materials can you use for magnetic particle inspection?

Common metallic materials like nickel, iron, steel, and cobalt are all ferromagnetic and perfect candidates for magnetic particle testing.

Why do we test magnetic particles?

Is magnetic particle examination a useful nondestructive examination method?

In conclusion, magnetic particle examination can be a useful nondestructive examination method during new construction and inservice inspections. It can only be used on ferromagnetic materials; therefore, it is not the best method for all applications.

What is the draft magnetic particle testing procedure?

This procedure is a draft magnetic particle testing procedure and you need to modify it to meet your project specification. 1.1 This procedure give the general requirements for carrying out the examination of welds in ferric materials using the AC electro magnetic yoke technique.

How much does a wet and magnetic particle examination cost?

Both wet method examinations have about the same sensitivity, but under correct lighting conditions, fluorescent indications are much easier to see. This type of stationary system can cost $15,000 or more. magnetic particle examination using an AC yoke with dry powder.

What is the difference between liquid penetrant and magnetic particle examination?

In the ASME codes of construction, magnetic particle examination or liquid penetrant examination is specified many times to detect the possibility of surface defects. If material is nonmagnetic, the only choice is liquid penetrant examination. However, if material is ferromagnetic, magnetic particle examination is generally used.