Which statement is true about magnetic particle testing?

Which statement is true about magnetic particle testing?

• A. It detects surface flaws and requires magnetizable metals.
• B. It detects interior flaws only.
• C. It cannot detect any surface flaws.
• D. It is a destructive test.

Answer: (A)

Magnetic particle testing uses a magnetic field to reveal flaws that interrupt the surface or run just beneath it in ferromagnetic materials. When a magnetized part has a crack or defect, leakage fields appear at the flaw and attract the finely divided magnetic particles, creating a visible indication. Because the method relies on magnetic properties, it only works on magnetizable metals, not non-magnetic ones. This makes it well-suited for finding surface and near-surface flaws, while it’s not meant for locating flaws deep inside the material. The statement that it detects surface flaws and requires magnetizable metals is the best description. The other options conflict with the non-destructive nature, the material requirements, or the location of detectable flaws.

Magnetic particle testing uses a magnetic field to reveal flaws that interrupt the surface or run just beneath it in ferromagnetic materials. When a magnetized part has a crack or defect, leakage fields appear at the flaw and attract the finely divided magnetic particles, creating a visible indication. Because the method relies on magnetic properties, it only works on magnetizable metals, not non-magnetic ones. This makes it well-suited for finding surface and near-surface flaws, while it’s not meant for locating flaws deep inside the material. The statement that it detects surface flaws and requires magnetizable metals is the best description. The other options conflict with the non-destructive nature, the material requirements, or the location of detectable flaws.