Carbon dioxide shielded welding full name carbon dioxide gas shielded arc welding. The protective gas is carbon dioxide (sometimes CO2+Ar mixture), mainly used for hand welding. Due to the special influence of the thermal and physical properties of carbon dioxide gas, when using conventional welding power supply, it is impossible to form a balanced axial free transition of molten metal at the end of the wire, which usually requires short circuit and droplet neck bursting. Therefore, compared with the free transition of MIG welding, more splash. However, if the high quality welder is used and the parameters are selected properly, the welding process can be very stable and the spatter can be reduced to a minimum degree. Due to the low price of the protective gas used, the weld is well formed when the short circuit transition is used, and the quality of the welding joint without internal defects can be obtained by using the wire containing deoxidizer. Therefore, this welding method has become one of the most important welding methods for ferrous metal materials.

Type of welding wire:

1. Solid welding wire

In order to prevent porosity, reduce sputtering and ensure that the weld has certain mechanical properties, the welding wire is required to contain enough alloying elements, generally limited carbon content (less than 0.1%), silicon manganese combined deoxidation. The diameter of the welding wire is commonly used: φ0.8mm φ0.9mm φ1.0mm φ1.2mm φ1.6mm, the allowable deviation of the welding wire diameter is +0.01, -0.04. The following describes several common welding wires.

① The welding wire for welding low carbon steel and low alloy steel is H08MnSiA, H08MnSi, H10MnSi.

② Welding wire used for welding low alloy steel strength steel are: H08Mn2SiA, H10MnSiMo, H10Mn2SiMoA.

③ The welding wire for welding bainitic steel is H08Cr3Mn2MoA.

④ Low splash welding wire used for welding micro-porosity resistance weld is: H0Cr18Ni9, H1Cr18Ni9, H1Cr18Ni9Ti.

⑤ Welding wire for stainless steel sheet: H0Cr18Ni9, H1Cr18Ni9, H1Cr18Ni9Ti, H1Cr18Ni9Nb.

2. Flux-cored welding wire

Flux-cored wire is made of thin steel tape rolled into a circular tube, which is filled with a pharmaceutical powder to draw the wire. Using flux-cored wire welding, forming gas-slag joint protection, good weld forming, welding splash small. Commonly used flux-cored welding wire are: YJ502, YJ507, YJ507CuCr, YJ607, YJ707.