What is the reason contamination is deposited in the weld during the GTAW process?

Contamination in the weld during the Gas Tungsten Arc Welding (GTAW) process is primarily attributed to the absence of flux. Unlike some welding processes that employ flux to shield the weld area from contaminants in the atmosphere, GTAW relies on an inert gas shield (usually argon or helium) to protect the weld pool. However, the effectiveness of this gas shield can be compromised by various factors, leading to contamination.

Since there is no flux in GTAW to absorb impurities or create a protective layer over the weld, any contaminants present in the base materials or the environment can lead to issues such as porosity, reduced strength, or poor aesthetics in the finished weld. Thus, the lack of flux specifically highlights the vulnerability of the weld area to contamination, making this the correct answer.