The welding rod is transported through the wire wheel, the conductive nozzle conducts electricity, generating electric isolation between the base material and the welding rod, melting the welding rod and the base material, and welding with rare gas argon to protect the electric isolation and the molten metal. With tungsten argon arc welding is different:First, the electrode as an electrode constantly melting to fill the solute pool, condensing to form a weld; Second, the protective gas. With the application of melting pole argon arc welding technology, shielding gas has been widely used in a variety of mixtures, such as Ar80% + CO220% argon-rich shielding gas. The former is called MIG, and the latter is called MAG. semi-automatic fusion electrode argon arc welding and argon-rich mixed shielding welding is most widely used in its mode of operation, followed by automatic fusion electrode argon arc welding.

Compared with tungsten argon arc welding, fused pole argon arc welding has the following characteristics.

Due to its high current strength, heat concentration, high deposition rate, fast welding speed and high efficiency. In addition, it is easy to lead the arc. It is necessary to strengthen the protection, because the arc light is strong and the smoke is big.

Argon is the most commonly used rare gas. It is a five-coloured odourless gas with an air content of 0. 935% (by volume), the boiling point of argon - between the boiling points of oxygen and helium, 186 ℃. Argon is a by-product of oxygen plant fractionation of liquid air to produce oxygen.

Canned argon is used for welding, the filling pressure is 15mpa at room temperature. cylinders are coated with grey paint and marked with the word "argon". Pure argon chemical composition requirements are as follows: Ar ≥ 99.99%; He ≤ 0.01%; O2 ≤ 0.0015%; H2 ≤ 0.0005%; the total amount of carbon ≤ 0.001%; moisture ≤ 30mg / m3. argon is a higher density than the air 25 ideal shielding gas. Argon is an ideal shielding gas with a density 25% higher than that of air, and flat welding is conducive to protecting the welding arc and reducing the consumption of shielding gas. Argon is a very inactive chemical gas, even at high temperatures will not react with the metal, leading to a series of problems, such as oxidative combustion of alloy components. Argon is also insoluble in liquid metals, so it does not cause porosity. Argon is a monatomic gas with an atomic state that does not decompose or absorb atoms at high temperatures. Argon specific heat capacity and thermal conductivity is small, that is, small absorption, less external heat transfer, electrical isolation in the heat is not easy to lose, so that the welding arc combustion is stable, the heat is concentrated, conducive to welding.