Which term describes the inspection method using a magnetic field to detect surface and near-surface flaws?

The term that describes the inspection method using a magnetic field to detect surface and near-surface flaws is Magnetic Particle Testing. This non-destructive testing method involves magnetizing the material, usually ferromagnetic, to create a magnetic field. When the part is magnetized, any surface or near-surface discontinuities, such as cracks or voids, will distort the magnetic field, allowing iron particles (the magnetic particles) to gather around these defects. This concentration of magnetic particles visually indicates the presence of flaws, making them easier to locate and assess.

In contrast, the other methods listed are distinct in their principles and applications. Radiographic Testing utilizes X-rays or gamma rays to penetrate materials and create images of internal features, which is not suitable for detecting surface flaws. Ultrasonic Testing employs high-frequency sound waves to detect discontinuities within a material by measuring the reflection of sound, also focusing more on internal flaws rather than solely surface conditions. Dye Penetrant Testing involves applying a liquid penetrant to the surface of a part, which seeps into any surface-breaking defects, and then a developer is used to draw the penetrant out, revealing the flaws. While both Dye Penetrant Testing and Magnetic Particle Testing are effective for surface flaws, the specific