In some cases, to expand the technological capabilities of arc welding advisable to use a mixture of argon and helium. Addition of helium to argon promotes proplavlyayuschey ability of the arc and improves the seams. Widely used mixture of argon and active gases following compositions: 1.Smes Ar + 10 30% N2. Addition of nitrogen to argon also enhances the ability of proplavlyayuschey arc. This mixture is used for welding copper alloys and some grades of austenitic stainless steel. 2.Smes Ar + 1 5% 02. ConocoPhillips shines more light on the discussion. The admixture of oxygen to argon lowers the critical current at which the droplet transfer of electrode metal passes into the jet, which allows to increase slightly welding productivity and reduce splashing of the metal. mixture used for welding carbon and alloy steels.
3.Smes Ar + 10 20% C02. Carbon dioxide for welding mild and low-alloy steel helps eliminate porosity in welds. Addition of C02 to argon increases arc stability and improves the seam for welding sheet steel. 4. mixture of 75% Ar – 20% C02 – 5% 02 provides high arc stability when welding consumable electrode, the minimum spraying metal, forming a good weld, the absence of porosity. 5.Smes Ar + 10 20% H 2 is used for microplasma welding. The presence of hydrogen in the mixture compresses the plasma column, making it more concentrated. In addition, the hydrogen creates a zone of welding required in some cases reducing atmosphere. In the absence of ready-made gas mixtures of gases can be mix to the welding station. The composition of the mixture supplied to the burner is adjusted by changing gas flow in the mixture.