AWS Welding Inspection and Testing Certification Practice Test

What type of welding might result in undercut from excessive heat?

1. GTAW

2. SMAW

3. FCAW

4. All types of welding

The correct answer is: All types of welding

Undercut is a common defect that can occur in various types of welding processes due to excessive heat input. Excessive heat can lead to the melting away of the base metal at the edges of the weld joint without depositing filler material, which creates a groove or undercut along the weld seam. This phenomenon is not limited to a specific welding technique; in fact, it can manifest in all types of welding. Gas Tungsten Arc Welding (GTAW) may produce undercut if the welder does not manage the heat correctly, particularly on thinner materials or when working with a narrow gap. Shielded Metal Arc Welding (SMAW) is also susceptible to undercut if the arc length is too long or if the travel speed is too slow, leading to excessive heating of the base metal. Flux-Cored Arc Welding (FCAW), similar in nature to SMAW but utilizing a tubular electrode, can also cause undercut for the same reasons related to heat management. Therefore, it is accurate to state that all welding processes can lead to undercut as a result of improper heat application, highlighting the importance of controlling heat input and technique in welding operations to minimize such defects.