What is the purpose of using circular and longitudinal magnetization in magnetic particle inspection?

The primary purpose of using circular and longitudinal magnetization in magnetic particle inspection is to reveal all possible defects present in a test specimen. This technique leverages the principles of magnetism, where magnetic fields are applied to the material being inspected.

Circular magnetization creates a magnetic field that encircles the part, making it sensitive to surface and near-surface defects. This is particularly effective for identifying cracks and discontinuities that may lie on the exterior of the part. On the other hand, longitudinal magnetization generates a magnetic field along the length of the part, which can be more effective in revealing defects that run parallel to the length of the component.

By employing both methods, inspectors can maximize their chances of detecting various types of defects, including those that might be oriented differently or hidden by the geometry of the object. This comprehensive approach ensures that the integrity and quality of materials can be thoroughly assessed, thereby enhancing reliability in structural applications.