This is a welding method with carbon dioxide gas as protective gas. Simple operation in application, suitable for automatic welding and full welding. There should be no wind when welding, which is suitable for indoor operation. Due to the low cost and easy production of carbon dioxide gas, carbon dioxide is widely used in carbon dioxide gas shielded welding (CO2 welding for short) in enterprises of all sizes, and sometimes the mixed gas of CO2 and O2 is also used. Due to the special influence of the thermophysical properties of carbon dioxide gas, it is impossible to form the axial free transition of metal liquid balance at the end of welding wire when using conventional welding power supply, and short circuit and droplet necking explosion are usually needed. Therefore, compared with the free transition of MIG welding, the spatter is more. However, if a high-quality welder is used and the parameters are properly selected, a very stable welding process can be obtained and splashing can be minimized. Because the shielding gas used is cheap, the weld seam is well formed when short-circuit transition is adopted, and the welded joint with deoxidizer and no internal defects is adopted. Therefore, this welding method has become one of the most important welding methods for ferrous materials.
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