CWI Weld Discontinuities and Defects 2

Question 1

Which discontinuity is characterized by a groove melted into the base metal adjacent to the weld toe that is left unfilled by weld metal?

Accepted Answer

Undercut

Answer

Overlap

Answer

Underfill

Answer

Cold lap

Question 2

Lamellar tearing in a weld joint is most likely to occur in which orientation relative to the base metal surface?

Accepted Answer

Parallel to the surface

Answer

Perpendicular to the surface

Answer

At 45 degrees to the surface

Answer

Along the weld centerline

Question 3

A weld that shows excessive convexity is most likely to cause which problem in service?

Accepted Answer

Stress concentration at the weld toes

Answer

Reduced tensile strength

Answer

Hydrogen cracking

Answer

Incomplete fusion

Question 4

Which type of crack propagates along the weld metal centerline, typically caused by solidification shrinkage and low-melting-point constituents?

Accepted Answer

Longitudinal centerline crack

Answer

Transverse crack

Answer

Toe crack

Answer

Root crack

Question 5

According to AWS standards, which condition describes 'overlap' in a weld?

Accepted Answer

Protrusion of weld metal beyond the weld toe onto base metal without fusion

Answer

Weld metal extending beyond the joint groove

Answer

Excessive reinforcement height

Answer

Weld metal deposited over a previous pass without cleaning

Question 6

A weld inspector finds scattered porosity throughout the weld. Which cause is LEAST likely responsible?

Accepted Answer

Excessive travel speed

Answer

Contaminated base metal

Answer

Moisture in the flux

Answer

Inadequate shielding gas coverage

Question 7

Which discontinuity is unique to resistance spot welding and appears as a hollow cavity within the nugget?

Accepted Answer

Shrinkage void (void in nugget)

Answer

Piping porosity

Answer

Expulsion void

Answer

Cold weld