AWS Welding Inspection and Testing Certification Practice Test

What term refers to a weld discontinuity caused by improper arc termination?

1. Undercut

2. Overlap

3. Crater crack

4. Incomplete fusion

The correct answer is: Crater crack

The term that refers to a weld discontinuity caused by improper arc termination is "crater crack." This type of defect occurs when the welder fails to properly terminate the arc at the end of a weld pass. If the arc is not extinguished with adequate technique, it can create a crater shape in the weld pool as the molten metal solidifies, which may lead to cracking. These cracks can significantly weaken the welded joint and can occur due to a variety of factors, including improper cooling rates and residual stresses created during the solidification process. Other terms in the list, such as undercut, overlap, and incomplete fusion, refer to different types of weld discontinuities. Undercut involves the removal of base metal on either side of the weld bead, which can reduce the strength of the weld. Overlap occurs when the weld metal flows over the base metal without proper fusion, creating a defect on the surface. Incomplete fusion describes a failure of the weld metal to properly bond with the base metal or previous weld passes, resulting in a potential weak spot. These terms do not specifically relate to the improper termination of the welding arc, which is the central aspect to identifying a crater crack.