Magnetic Particle Inspection Level 2 Practice Exam

Which type of flaw is indicated by an irregular indication that turns off slightly from the axial direction?

1. Porosity

2. Weld shrinkage cracks

3. Casting defects

4. Surface flaws

The correct answer is: Weld shrinkage cracks

The type of flaw indicated by an irregular indication that turns off slightly from the axial direction is associated with weld shrinkage cracks. These cracks typically form due to the stresses that occur during the cooling and solidification of the weld metal. When a weld cools, it contracts, which may lead to cracking, especially if there are any discontinuities or if the weld is improperly executed. Weld shrinkage cracks can produce irregular magnetic particle indications because their orientation and nature can be quite varied, which can result in indications that may not align perfectly with the axial direction of the material. The turning off of the indication slightly from the axial direction signifies that the flaw is not aligned uniformly, which is characteristic of weld shrinkage cracks rather than other types of flaws. Other types of flaws, such as porosity or casting defects, typically show more consistent directional characteristics in their indications. Surface flaws, while they may cause irregular indications, are generally more shallow and don't typically manifest as irregularities turning off from the axial direction. Thus, the identification of weld shrinkage cracks based on the observed irregularity aligns well with the behavior of these cracks in a magnetic particle inspection context.