Which impurity is tungsten most sensitive to when exposed during welding?

Tungsten is particularly sensitive to oxygen during welding because oxygen can lead to the formation of tungsten oxides, which can degrade the mechanical properties and electrical conductivity of the tungsten electrode. When tungsten is contaminated with oxygen, the welding arc can become unstable, causing irregularities and defects in the weld. This sensitivity is critical in processes like Gas Tungsten Arc Welding (GTAW), where maintaining the integrity of the tungsten electrode is essential for achieving high-quality welds.

While other impurities like hydrogen, carbon, and nitrogen can also affect the properties of tungsten and the welding process, oxygen is the primary concern due to its tendency to form compounds that can severely impact the overall quality of the weld and the performance of the welding electrode. Therefore, careful control of the welding environment to minimize exposure to oxygen is a fundamental aspect of maintaining the efficacy of tungsten in welding applications.