What gas is used for gas arc welding?

Gas shielded welding includes TIG and GMAW.

(1) Metal inert gas usually uses argon, helium or the mixed gas of argon and helium as protective gas. The droplet transfer mode is spray transfer or pulse spray transfer, which is suitable for welding various non-ferrous metals, austenitic stainless steel and high temperature alloys.

(2) The shielding gas of oxidizing mixed gas shielded welding is composed of inert gas and a small amount of oxidizing gas-O2, CO2 or their mixed gas (generally 2% ~ 5% for O2 and 5% ~ 20% for CO2). The droplet transfer mode is short circuit transfer, spray transfer or pulse spray transfer, which is suitable for welding ferrous materials such as carbon steel, alloy steel and stainless steel.

Extended data

Advantages of gas shielded welding:

1. The welding cost is low. Its cost is only 40~50% of submerged arc welding and covered electrode arc welding.

2. The production efficiency is high. Its productivity is 1~4 times that of covered electrode arc welding.

3. Simple operation. Open arc, unlimited workpiece thickness, all-position welding, downward welding.

4. The weld has high crack resistance. The content of hydrogen and nitrogen in weld is low.

5. Small deformation after welding. The angular deformation is five thousandths and the roughness is only three thousandths.

6. Welding spatter is small. When using ultra-low carbon alloy welding wire or flux-cored welding wire, or adding Ar into CO2, welding spatter can be reduced.