Shielding gas is far more than a protective cover for the molten pool. Its composition directly influences arc stability, penetration depth, weld appearance and even mechanical properties.
For MIG/MAG welding of carbon steel, a mix of argon with CO₂ or O₂ improves arc stability and fusion. Argon-rich mixes suit stainless steel, while helium addition raises heat input for thicker sections.
For TIG and plasma hardfacing, pure argon or argon-based mixtures keep the tungsten electrode clean and protect overlay alloys such as Stellite from oxidation. Inert gas purity matters — moisture or impurities can lead to pores and reduced corrosion resistance.
Selecting the correct gas and flow rate is a simple but often overlooked step that strongly affects your weld quality and production cost.