AWS Certified Welding Inspector — FundamentalsNondestructive Examination (NDE)Easy
A CWI is conducting a visual inspection of a plate edge prepared for welding. The edge exhibits small, shallow, irregularly shaped indentations or gouges that appear to be caused by mechanical abrasion, rather than intentional machining. This condition is best described as:
- AScabs.
- BLaminations.
- CMechanical damage.
- DDelaminations.
Show answer & explanationAnswer & explanation
Correct answer: C. Mechanical damage.
Mechanical damage refers to any physical alteration to the material's surface or subsurface caused by external forces, such as impacts, abrasion, or improper handling. Small, shallow, irregularly shaped indentations or gouges on a plate edge fit this description, distinguishing them from inherent material defects or specific weld discontinuities.
Why the other options are wrong
- A. Scabs are irregular, loosely attached pieces of metal on the surface, usually from rolling or casting, not typically 'gouges' caused by abrasion.
- B. Laminations are internal material separations parallel to the surface, not surface indentations.
- D. Delaminations are separations within a layered material or along a bond line, similar to laminations but often referring to composite structures or coatings.
VT - Mechanical Damage
Mechanical damage refers to surface or subsurface discontinuities caused by external mechanical forces like grinding, impact, or abrasion, resulting in indentations, gouges, or scratches.
- Caused by external forces.
- Includes dents, gouges, scratches.
- Visible on the surface.
- Distinguished from inherent material defects.
Memory trick: Look at the base metal, not just the weld.