Shielding gas mixture 82/18
Mixed gas 82/18 consists of 82 % argon and 18 % carbon dioxide. It's used for MAG welding to reduce spatter and improve penetration.
Physical-chemical mechanism of action
Shielding gas mixture 82/18 consists of argon (Ar) and carbon dioxide (CO₂). Argon shields the weld area from oxidation, while carbon dioxide promotes the electrolysis of the steel and improves penetration. The specific composition of 82/18 optimizes these effects.
Metallurgical relevance & welding risks
Correct use of shielding gas 82/18 minimizes spatter, giving a cleaner weld and longer electrode life. Too little CO₂ can hurt penetration, while too much CO₂ can raise arc voltage, causing spatter and possibly hot cracks.
Shop practice & procedures
Use shielding gas 82/18 for MAG welding of mild and low-alloy steels. Make sure the gas is mixed at a ratio of 82/18. Check the gas supply regularly to keep the mix consistent. An uneven mix can lead to spatter and hot cracks.