The research on CO2 gas shielded welding began in 1955 and was put into production practice in 1960. For half a century, CO2 gas shielded welding has been widely used in shipbuilding, locomotive manufacturing, automobile manufacturing, petrochemicals, construction machinery, agricultural machinery, etc. CO2 gas shielded welding has become one of the important welding methods today.
CO2 gas shielded welding is a fusion welding method that uses electric arc as a heat source. In the fusion welding process, in order to obtain high-quality welds, the welding area must be effectively protected to prevent the intrusion of harmful gases in the air; in order to meet the needs of the welding metallurgical process, the form of gas protection is adopted. The use of gas shielded gas shielded arc welding can reliably ensure welding quality and make up for the limitations of manual electric arc welding. Moreover, gas shielded welding has unique advantages in terms of thin plate and high-efficiency welding. Therefore, it is used in welding production. The application is becoming more and more extensive.
The arc method that uses external gas as the arc medium and protects the arc and the welding area is called gas shielded arc, or CO2 gas shielded welding for short. CO2 Gas shielded welding directly relies on the continuous air flow from the nozzle to create a local gas protection layer around the arc, so that the electrode end, the molten drop and the molten pool metal are in the protective gas hood, and the air is mechanically isolated from the welding area. Ensure the stability of the welding process and obtain high-quality welds.
One end of the electrode has a high melting point and cannot be melted during the welding process. For example, tungsten arc welding uses metal tungsten as one end of the electrode. During welding, an arc is formed between the tungsten electrode and the base material, releasing high-temperature melting of the base material It forms a weld with the metal fed into the arc.The metal tungsten does not melt during the welding process, and the metal tungsten end is the non-melting electrode.
One end of the electrode has a low melting point and is melted as a filler metal during the welding process. The electrode end is the melting pole;