Which nondestructive testing method would detect internal weld flaws without cutting the metal?

Which nondestructive testing method would detect internal weld flaws without cutting the metal?

• A. Radiographic examination
• B. Visual inspection
• C. Dye penetrant examination
• D. Magnetic particle inspection

Answer: (A)

Radiographic examination uses penetrating radiation to visualize the interior of a weld, so it can reveal flaws that lie inside without cutting the metal. X-rays or gamma rays pass through the weld and surrounding material, and differences in density or thickness show up as contrasts on the radiograph. Internal issues like porosity, voids, inclusions, or lack of fusion appear as distinct features on the image, allowing you to assess the weld’s integrity without removing material.

Visual inspection only sees surfaces, missing internal defects. Dye penetrant looks for surface-breaking flaws by allowing dye to seep into surface openings, so it won’t reliably reveal flaws inside the metal. Magnetic particle inspection can detect defects by noticing magnetic flux leaks, which highlights surface and near-surface defects in ferromagnetic materials, but it isn’t effective for internal flaws away from the surface.