What is burn-through in the context of GTAW?

Burn-through refers to a defect that occurs when excessive heat is applied to thin materials during the welding process, resulting in holes or perforations. In Gas Tungsten Arc Welding (GTAW), the precision of the process can sometimes lead to unintended excessive heating, especially when working with materials that have low thermal mass or are particularly thin. When the heat input is too high, the base metal can melt through entirely, leading to a loss of material integrity and creating an undesirable hole.

Understanding burn-through is crucial for welders, particularly when they are working on thin sections where controlling the heat input is vital for maintaining the quality of the weld. This defect can compromise the strength and appearance of the weld, as well as potentially causing other issues like distortion or weakening of the part being welded. Therefore, recognizing the conditions that lead to burn-through is imperative in achieving successful and effective welding outcomes.