Why argon and helium gas welding is important

When welding, particularly arc welding, it is key that your use some form of shielding or welding gas. Argon and helium gas welding provides more suitable conditions for the welding arc by protecting it from the damaging effects of the surrounding air. If a welding arc comes into contact with heated metal, the oxygen will begin to oxidise the metal.

Additionally, nitrogen or moisture in the air might cause the welding to become porous or brittle. All of these factors are undesirable when creating strong, durable welding joints. The presence of welding gas thus improves the surface appearance and geometry of welds, while ensuring arc stability and increased metal transfer. Welding gases also burn off alloying elements and oxide formation on the bead surface. By using welding gas you can increase your overall welding speed.

Should I be welding with argon gas or helium gas?

The two most common forms of shielding gas are argon and helium (or a mixture of the two). Argon is a naturally occurring non-flammable and non-toxic gas that is colourless, odourless and chemically inert. Argon is particularly effective in protecting weld sites from detrimental atmospheric influences, such as oxygen, nitrogen, and water particles. As such, Argon is commonly used in welding and other high-temperature industrial processes, which often cause non-reactive materials to become reactive. Argon is the best gas for shielding tungsten arc welding with an alternating current (AC). It provides extremely stable and quick starting arcs as well as cleaner welds. Argon gas is also the most commonly used shielding gas for welding aluminium.

Pure helium, on the other hand, is used more commonly in direct current electrode negative (DCEN) gas tungsten arc machine welding. Pure helium provides high heats which result in fast welding speeds and deeply penetrating welds. This is particularly useful when creating full penetration butt welds, which are only welded from one side.

Argon and helium mixtures also produce high welding heat and sometimes an increased welding speed. The most common mixture is 25% helium and 75% argon. This mixture is most commonly used in AC gas tungsten arc welding. Occasionally mixtures of more than 25% helium are used, however they can result in arc instability.

If you are interested in obtaining rent free welding gas or shielding gas, contact Rent Free Gas today on 1300 792 603.