Which of the following can be an example of a non-relevant magnetic irregularity?

An example of a non-relevant magnetic irregularity is an abrupt change in the hardness of the part. In magnetic particle inspection, the focus is on detecting flaws or discontinuities that can affect the integrity of the material, such as cracks or voids. An abrupt hardness change, while it may indicate some aspect of material property variation, does not inherently create a magnetic field disturbance that would lead to a false indication during magnetic particle testing.

Relevant magnetic irregularities typically include features like slag pockets, grinding cracks, and metal fatigue, which can lead to significant flaws and are likely to affect the material's performance. These irregularities result in changes to the magnetic field when particles are applied, leading to visible indications during inspection. The abrupt change in hardness, however, does not generate a magnetic indication and thus can be considered non-relevant in the context of magnetic particle inspection.

Understanding the difference between relevant and non-relevant irregularities is crucial for effective inspection and interpretation of results. This distinction ensures that inspectors can accurately assess the condition of materials and identify genuine defects that could compromise safety and integrity.