.svg)
Shielding Gas
A gas or gas mixture, such as argon, CO2, helium, or blended mixtures, used during welding to displace atmospheric oxygen and nitrogen from the weld zone and prevent oxidation of the molten weld pool.
Shielding gas selection fundamentally impacts arc stability, spatter generation, bead geometry, and corrosion resistance; pure argon produces clean, ductile welds in stainless and aluminum but offers poor penetration in structural steels, while CO2-rich blends achieve deeper penetration in carbon steel but increase spatter and gas consumption. Helium additions increase heat input and penetration at the cost of arc instability and higher gas cost, making helium primarily useful for specialty applications like heat-exchanger tube joining.
The flow rate of shielding gas must be tuned for the nozzle geometry, travel speed, and ambient conditions; excessive flow causes turbulence and air entrainment, while inadequate flow allows atmospheric oxygen and nitrogen to contaminate the molten pool. Proper gas purity is critical, even trace moisture or oxygen in the supply cylinder introduces porosity and embrittlement, making cylinder management and line purging essential elements of any welding procedure specification.
Price Your Project
Receive a free, custom quote for you project. Midwest Metal Fabrications can handle any job, small or large and is ISO 9001:2015 and AS9100 Certified.