Active Shielding Gas
Active shielding gas is a gas mixture for MAG welding that contains reactive components such as carbon dioxide or oxygen in addition to inert gases. These additives stabilize the arc and positively influence metallurgical reactions in the weld pool.
Physicochemical Mechanism of Action
Active shielding gas contains reactive components such as carbon dioxide (CO2) or oxygen (O2) in addition to inert gases like argon or helium. These additives work in the weld pool by supporting the electrolysis of the steel and stabilizing the arc. They also promote the oxidation of the metals, which leads to better melt distribution.
Metallurgical Relevance & Risks in Welding
The use of active shielding gases can improve the quality of the weld seam by increasing strength and toughness. However, too high a content of reactive gases can lead to overexcitation of the arc, which can cause irregular melt paths and possibly hot cracks or distortion. It is important to choose the correct gas mixture and set the welding parameters carefully.
Workshop Practice & Instructions
Use active shielding gases with the specified gas mixture in the welding machine. Pay attention to the correct pressure and temperature of the weld pool. Monitor the melt paths and adjust the gas quantity or mixture if necessary. If you encounter problems with irregular melt paths or hot cracks, check the gas mixture and welding parameters.