What is argon arc welding?

Argon arc welding is a welding technology that uses argon as a protective gas. [1] Also called argon gas shielded welding. It is to pass argon protective gas around the arc welding to isolate the air from the welding area and prevent oxidation of the welding area.

Argon arc welding technology is based on the principle of ordinary arc welding, using argon gas to protect metal welding materials, and using high current to melt the welding materials into a liquid state on the base material to be welded to form a molten pool, so that the metal to be welded and the welding material are A welding technology that achieves metallurgical bonding of materials. Since argon gas is continuously supplied during high-temperature molten welding, the welding material cannot come into contact with oxygen in the air, thus preventing the oxidation of the welding material. Therefore, stainless steel and iron hardware metals can be welded .

efficient
The current density is large, the heat is concentrated, the deposition rate is high, and the welding speed is fast. In addition, it is easy to strike an arc. Protection needs to be strengthened because the arc light is strong and the smoke is large, so protection must be strengthened.
Protective gas
The most commonly used inert gas is argon. It is a colorless and odorless gas with a content of 0.935% in air (calculated by volume). The boiling point of argon is -186°C, which is between the boiling points of oxygen and helium. Argon is a by-product of oxygen plants fractionating liquid air to produce oxygen.
Bottled argon is used for welding in China, and its filling pressure is 15MPa at room temperature. The cylinder is painted gray and marked "Argon". The chemical composition requirements of pure argon are: Ar ≥ 99.99%; He ≤ 0.01%; O2 ≤ 0.0015%; H2 ≤ 0.0005%; total carbon content ≤ 0.001%; moisture ≤ 30mg/m2.
Argon is an ideal protective gas, which is 25% denser than air. It is helpful for protecting the welding arc during flat welding and reducing the consumption of protective gas. Argon is a gas with very inactive chemical properties. It does not react chemically with metals even at high temperatures, so there is no oxidation and burning loss of alloy elements and a series of problems caused by it. Argon is also insoluble in liquid metal and will not cause porosity. Argon is a monatomic gas that exists in an atomic state and has no molecular decomposition or atomic endothermy at high temperatures. The specific heat capacity and thermal conductivity of argon are small, that is, the amount of argon absorbed is small and the heat transfer is small. The heat in the arc is not easily lost, which makes the welding arc burn stably and concentrates the heat, which is beneficial to the welding process.
The disadvantage of argon is its higher ionization potential. When the arc space is filled with argon gas, it is more difficult to ignite the arc, but once the arc is ignited, it is very stable.