Magnetic Particle Inspection Level 1 Practice Exam

What type of defect might be detected using prods in magnetizing a weld area?

1. Inclusions

2. Surface cracks

3. Subsurface discontinuities

4. All of the above

The correct answer is: All of the above

The use of prods in magnetizing a weld area during Magnetic Particle Inspection (MPI) is a technique designed to reveal various types of defects. Prods create an electromagnetic field in the material being tested, which encourages magnetic particles to gather at defect sites. Inclusions, defined as unwanted materials trapped within the weld metal, can be detected when they disrupt the magnetic field, causing magnetic particles to cluster around them. Surface cracks are also identifiable with this method. Since they are located on the surface of the weld, the magnetic particles will accumulate along these cracks, highlighting their presence. Furthermore, subsurface discontinuities — which refer to flaws located beneath the surface, like voids or micro-cracks — can sometimes be detected if they are sufficiently close to the surface. While the detection of subsurface defects is less reliable than that of surface flaws, the use of prods can still uncover indications of deeper issues if the electromagnetic field penetrates adequately. Due to the capability of prods to reveal inclusions, surface cracks, and certain subsurface discontinuities, the correct answer encompasses all of these possibilities.