Which condition would lead to increased oxidation in a GTAW weld?

Increased oxidation in a GTAW weld is most likely to occur when the welding is delayed after joint preparation. When a joint is prepared for welding, it is often cleaned to remove contaminants such as rust, oil, or moisture that could otherwise compromise the quality of the weld. If there is a significant delay before welding, the clean surfaces are exposed to air, which can lead to oxidation. This oxidation can form a layer of oxide on the joint surfaces, which must be removed or mitigated for a successful weld.

Effective shielding gas, proper torch positioning, and maintaining a suitable torch angle are all practices that help to reduce oxidation by providing protection during the welding process. For instance, shielding gas creates an inert atmosphere that protects the weld pool from atmospheric contamination, while correct torch positioning and angle allow for optimal coverage and control during the welding operation. In contrast, a delay before welding allows for potential oxidation to occur, thus deteriorating the integrity of the weld joint and making it prone to defects.