Which of the following is a function of shielding gases in GMAW?

The function of shielding gases in Gas Metal Arc Welding (GMAW) is primarily to protect the weld area from atmospheric contamination, particularly oxidation. When metal is heated during the welding process, it becomes susceptible to reacting with elements in the air, such as oxygen and nitrogen, which can lead to defects like porosity and a weak weld. By using shielding gases, welders create an inert atmosphere around the weld pool, preventing oxidation and promoting a stronger, cleaner weld. This is vital for ensuring the integrity and durability of the weld in structural applications.

Other purposes, such as improving weld penetration or ensuring proper cooling, are influenced by different factors, including the welding parameters and techniques used, rather than being direct functions of the shielding gas. Enhancements to metal flow can also occur through adjustments in technique and equipment settings, rather than relying solely on the presence of shielding gas.