Causes of Undercut Defects

During the welding process, if a depression is formed at the edge of the weld, causing the weld seam to be lower than the base material, this depression is known as an undercut defect. There are various causes of undercut defects. For instance, welding too quickly or using a high welding current, which enhances the arc, can both lead to the occurrence of undercut defects. Additionally, welding depth fluctuations due to issues with the welding machine's weld bead during the welding process can make it difficult for the weld metal to be replenished, resulting in severe strain phenomena. Therefore, during spiral steel pipe welding operations, it is important to avoid the occurrence of undercut defects as much as possible.