17 Mar 2022
How much do you know about carbon dioxide gas shielded welding? Let's go into detail. First of all, let's talk about the origin of the carbon dioxide gas shielded welding process. The CO2 welding process was originally conceived in the 1920s, however, due to the unresolved problem of weld porosity, CO2 welding cannot be used. It was not until the early 1950s that the development of welding metallurgy technology solved the metallurgical problem of CO2 welding, and the Si-Mn series of welding wires were developed, which made the CO2 welding process obtain practical value. After that, according to the performance of structural materials, welding wires with different components appeared one after another, which met the diversified needs of CO2 welding. At present, carbon dioxide gas shielded welding machine are widely used not only in various large and small enterprises, but also in shipbuilding, automobile manufacturing, vehicle manufacturing and petrochemical industries. It can be seen that the practical application of CO2 welding process has brought great wealth to the society.
Then we start from the definition of carbon dioxide gas shielded welding. It is a method of welding with carbon dioxide gas as a protective gas. (Sometimes a mixed gas of CO2+Ar is used). Using the welding wire and the workpiece as two electrodes, an arc is generated, the heat of the arc is used to melt the metal, and carbon dioxide gas is used as a protective gas to protect the arc and molten pool, so as to obtain a good welding joint. This welding method is called carbon dioxide gas shielded welding. (Figure 2). Carbon dioxide gas shielded welding is a high-efficiency and low-cost welding method. It is mainly used for the welding of low carbon steel and low alloy steel; It can not only weld thin plates, but also medium and thick plates and thick plates, and can weld all positions at the same time. Carbon dioxide gas is easy to produce, with low cost, good weld formation when short-circuit transition is used, and high-quality welded joints without internal defects can be obtained by using welding wire containing deoxidizer. This welding method has become the most important welding method for ferrous materials.
Then we talk about the advantages of carbon dioxide gas shielded welding. First, high productivity. Since the welding wire is continuously fed, the welding speed is fast and the current density is high. Compared with the electrode arc welding, the deposition rate is higher, and the slag cleaning is generally not required after welding, so the production efficiency is 1~3 times higher than that of the electrode arc welding. Second, the quality of the welds is high. Strong rust resistance, low hydrogen content in welds, and low tendency to cold cracks when welding low-alloy high-strength steels. Third, welding deformation and stress are small. Due to the concentrated heat of the carbon dioxide gas shielded arc welding, the heat affected zone is small, so the deformation is small, and it is suitable for all-position welding. Fourth, low cost. Carbon dioxide gas is cheap, and its welding cost is only 40% to 50% of that of submerged arc welding and electrode arc welding.
Let's talk about the disadvantages of carbon dioxide gas shielded welding. First, during the welding process, when the welding parameters are not matched properly, there is a lot of metal spatter. The spatter will not only stick to the inner wall of the nozzle at the end of the contact tip, causing poor wire feeding, reducing the gas protection effect, and making the arc combustion unstable, but also reducing the welding wire deposition coefficient and increasing the welding cost. Second, the ability to resist wind is weak, and outdoor operations need to have wind protection measures. Third, the arc atmosphere has a strong oxidizing property, and it is not suitable for welding easily oxidized metals. Fourth, semi-automatic torches are heavier than electrode arc welding guns and have less operational flexibility. For welding joints in tight spaces, the welding torch is not easy to approach. Fifth, due to the high current density used and the strong arc light radiation, it is necessary to protect the body and eyes during operation.
In general, carbon dioxide gas shielded welding is easy to operate in terms of application, suitable for automatic welding and all-round welding. It has poor wind resistance during welding and is suitable for indoor operation. Due to the special influence of the 0 thermophysical properties of carbon dioxide gas, when using a conventional welding power source, it is impossible for the molten metal at the end of the welding wire to form a balanced axial free transition. More splashes compared to transitions. However, if a high-quality welding machine is used, and the parameters are selected properly, a very stable welding process can be obtained, and the spatter can be reduced to a minimum. And our Kingsiri brand carbon dioxide welding machine is very in line with the standard of high-quality welding machine, easy to operate, good welding effect and beautiful welding seam.
Keywords: welding machine
Originally published 17 Mar 2022, updated 17 Mar 2022.