AWS Weld Discontinuities & Defects 5

Question 1

A weld cross-section shows weld metal that has rolled over the base metal surface without fusing to it. This discontinuity is called:

Accepted Answer

Overlap

Answer

Overlap (also called cold lap) occurs when weld metal flows over the base metal surface and solidifies without achieving fusion, creating a notch-like condition.

Question 2

Which type of porosity is characterized by a single large void elongated along the weld axis?

Accepted Answer

Wormhole (piping) porosity

Answer

Wormhole or piping porosity consists of elongated tubular voids that form parallel to the weld axis due to gas escaping during solidification.

Question 3

During multi-pass welding, which action is MOST important to prevent inter-pass slag inclusions?

Accepted Answer

Thoroughly removing slag between passes

Answer

Thorough slag removal between passes prevents slag from being trapped under subsequent weld beads, which would create slag inclusions.

Question 4

Incomplete joint penetration (IJP) in a groove weld is MOST commonly caused by:

Accepted Answer

Insufficient groove angle or root opening

Answer

Insufficient groove angle or inadequate root opening prevents the arc from reaching the root of the joint, resulting in incomplete joint penetration.

Question 5

Which of the following BEST describes a 'cold crack' in welding?

Accepted Answer

A crack that forms at or near room temperature after the weld has cooled

Answer

Cold cracks (hydrogen-induced cracks) form at or near room temperature after the weld cools, driven by hydrogen, residual stress, and a susceptible microstructure.

AWS Practice Test

AWS Practice Test

AWS Weld Discontinuities & Defects 5