Magnetic Particle Inspection Report Template and sample PDF

Magnetic particle inspection is one of the major and oldest non-destructive testing methods that focuses primarily on surface-level inspections. Just like most noninvasive surface-level inspections, it’s quick and low-cost. While it does not give information on the defect depth and cannot cover complex geometrical shapes, it still does the job of sensing discontinuity in the surface of parts. How is it done and what are the procedures involved?

Preparation and Magnetization

This process involves preparing the component to be inspected, making sure it’s cleaned and dried of grease and oil, and preparing the materials needed, which include the specific magnetic powder and yoke.
Magnetic powders are key ingredients in magnetic particle inspection as it will trigger the detection of the surface defects.

There are three powders to choose from depending on their visibility and application.

• Dry magnetic particles - which are usually red, black, or yellow in color. These are fine dry and visible in natural light and is usually used for field welds and rough surfaces.
• Wet magnetic particles - these are suspended in oil or water and is more sensitive than dry powders but makes is easier to apply to a large area.
• Wet fluorescent particle - these are coated with pigments of hat fluoresce when exposed to ultraviolet light. The particles used with the wet method are smaller in size than those used in the dry method. (Iowa State University, Center for Nondestructive Testing)

Yokes are portable U-shape electromagnetic devices that would provide the necessary magnetic field that would visualize the imperfections. It’s a key inspection device to prepare to detect surface and sub-surface cracking.

Application of the magnetic particles

Basically, if there is a defect or crack in the surface of the component, the magnetic particle senses the discontinuity and is drawn to it. This then changes the permeability of the material, and when the specimen or the test piece is magnetized, the magnetic field is distorted. After this, the inspector has to visually inspect the component under appropriate lighting. Surface fluorescent particles are visible under UV light.

An example here from the data of the magnetic particle inspection report you can preview above: a weld pipe is inspected using the wet fluorescent method. After degreasing the pipe, a yoke is placed across the weld seam to magnetize the area. Then, a fluorescent magnetic ink is sprayed onto the surface. Under the UV light, any surface-breaking crack will create a glowing indication which would be easy to detect by the inspector, and it highlights the location, shape and extent of the defect.

Magnetic particle inspection report

The last essential procedure of this testing method is the magnetic particle inspection report. This is when the findings are documented, with photos or sketches of the indications of the defect.