Why is it important to use the correct gas flow rate in GTAW?

Using the correct gas flow rate in Gas Tungsten Arc Welding (GTAW) is vital primarily because it prevents oxidation and contamination of the weld pool. In GTAW, an inert gas, typically argon or helium, is used to shield the weld area from atmospheric gases. If the flow rate is too low, there may be insufficient shielding, which can lead to oxidation of the weld metal and contamination by surrounding air. This can weaken the weld, leading to defects such as porosity, inclusions, or weak joints.

On the other hand, if the flow rate is too high, it may cause turbulence, which can also bring atmospheric contaminants into the weld pool. Thus, maintaining an appropriate gas flow rate ensures that the weld pool is properly protected, resulting in stronger, higher-quality welds and reducing the risk of defects.