AWS Welding Inspection and Testing Certification Practice Test

A weld metal discontinuity caused when the welder fails to completely fill the weld groove is called?

1. Underfill

2. Undercut

3. Overlap

4. Incomplete fusion

The correct answer is: Underfill

The term that describes a weld metal discontinuity resulting from the welder not fully filling the weld groove is known as underfill. Underfill occurs when there is insufficient weld metal in the groove, which may compromise the strength and integrity of the weld joint. This discontinuity can lead to a reduction in the ability of the weld to withstand applied loads, making it critical for inspectors to identify and assess underfilled welds. Understanding underfill is essential in the welding inspection process because it directly affects the structural performance of welded components. Recognizing this type of discontinuity helps ensure that welds meet specified standards and requirements for strength. In this context, the other terms refer to different types of welding discontinuities: undercut refers to a groove or notch that is created at the base of the weld bead; overlap is when weld metal spreads over the surface of the base material without proper bonding; and incomplete fusion is when the weld metal does not adequately bond to the base material or to the preceding weld bead. Each term describes a specific defect, and differentiating between them is vital for effective weld quality assessment.