Which combination of NDE methods is commonly used to inspect welds?

• A. Ultrasonic testing (UT) and radiographic testing (RT) only
• B. Dye penetrant testing (PT) and magnetic particle testing (MT) only
• C. Ultrasonic testing (UT), radiographic testing (RT), dye penetrant testing (PT), magnetic particle testing (MT), and eddy current testing (ET)
• D. Visual inspection only

Answer: (C)

Weld inspection relies on using several nondestructive examination techniques because flaws can be different in type and where they occur. Ultrasonic testing looks into the interior and can size and locate internal flaws by sending sound waves and measuring reflections. Radiographic testing provides a image-like view of the weld’s interior, revealing volumetric issues such as porosity, inclusions, or lack of fusion. Dye penetrant testing makes surface-breaking cracks visible by seeping dye into openings and highlighting them on the surface. Magnetic particle testing detects surface and near-surface cracks in ferromagnetic materials by imaging how magnetic particles gather at defect regions. Eddy current testing is sensitive to surface and near-surface defects and can also indicate changes in material properties and thickness in conductive metals.

Using all five methods gives broad and complementary coverage, addressing internal, surface, and near-surface flaws across a range of materials. Visual inspection alone can miss subsurface defects; relying on only one technique might miss defect types that another method would detect. Therefore, the combined set of ultrasonic, radiographic, dye penetrant, magnetic particle, and eddy current testing is a common, effective approach for weld inspection.