What Is Inert Gas Welding?

MIG welding is a welding method in which an inert gas covers the welding part to promote the stability of the arc and prevent changes in welding quality. The arc is used to melt the metal in the welding part and send it to the welding rod to connect the welds. Or carbon dioxide arc welding.

MIG welding is a welding method in which an inert gas covers the welding part to promote the stability of the arc and prevent changes in welding quality. The arc is used to melt the metal in the welding part and send it to the welding rod to connect the welds. Or carbon dioxide arc welding.

Chinese name

MIG welding

Another

Semi-automatic welding

Introduction to MIG welding

Since the beginning of auto body repair, oxyacetylene gas welding has been used, and the workload is the largest. Although resistance spot welding is also used, its welding position is limited, and the quality of welding is greatly affected by the state of mechanical equipment, so reliability cannot be guaranteed. Arc welding is not suitable for welding of body panels due to its large deformation. Brazing and soldering are low-temperature welding. Although its advantage is that the deformation is small, the fatal weakness is insufficient strength, so it is not suitable for welding of integrated body. Gas welding is gradually eliminated due to the large amount of thermal deformation and oxidation after welding.

Recently, the automobile body repair industry has widely adopted a new welding technology-MIG welding (Metal Inert Gas Arc Welding), which is an inert gas shielded arc welding. MIG welding is a welding method in which an inert gas covers the welding part to promote the stability of the arc and prevent changes in welding quality. The arc is used to melt the metal in the welding part and send it to the electrode to connect the welds. Or carbon dioxide arc welding.

MIG Features of MIG welding

(1) The inert gas is continuously blown out from the welding tip to completely cover the welding part, so that the weld bead is not oxidized by oxygen in the air. In addition, since a large current is concentrated in the welding portion, heat can be locally concentrated and welded very quickly, so the amount of deformation that occurs is small.

(2) The welding rod is automatically and continuously sent out, so there is no bead joint, and continuous welding can be performed.

(3) The temperature rise is low, so it can be used for butt welding of very thin plates. When covering welding, no welding slag will be generated on the bead, and the slag removal work can be avoided.

(4) The combination of welding machine, welding wire feeding mechanism and welding machine body for vehicle body repair is installed on the cart with wheels together with the gas cylinder, which is easy to move in conjunction with on-site operations.

(5) The special welding machine for body repair is equipped with MIG spot welding mechanism, which can do single-sided resistance spot welding. For areas where spot welding cannot be reached with the electrode clamp arm, single-sided spot welding works well.

MIG Working principle of MIG welding MIG semi-automatic welding machine

The principle of MIG welding is the same as that of general arc welding, except that the conventional covered electrode is replaced by a continuous disc-shaped bare electrode with a small diameter. Covering the welding part with an inert gas is equivalent to the role of the electrode flux, protecting the bead from air The intrusion of oxygen, nitrogen and water vapor affects the quality of the bead.

Inert gases include helium (He), argon (Ar), and other mixed gases argon-oxygen, argon-carbon dioxide, and the like. Due to welding performance and economics, there are many welding machines using carbon dioxide gas, namely carbon dioxide semi-automatic arc welding machines. This is because the low-carbon steel for automobile bodies is most suitable for carbon dioxide welding.

MIG Advantages of MIG welding

(1) Low welding cost. Its cost is only 40-50% of submerged arc welding and manual arc welding.

(2) High production efficiency. Its productivity is 1-4 times that of manual arc welding.

(3) Easy operation. Open arc, unlimited thickness of the workpiece, can be welded in all positions and can be welded down.

(4) The crack resistance of the weld is high. Welds have low hydrogen and low nitrogen content.

(5) Less deformation after welding. The angular deformation is five thousandths, and the unevenness is only three thousandths.

(6) Welding spatter is small. When using ultra-low carbon alloy wire or flux-cored wire, or adding Ar to CO2, welding spatter can be reduced ^[1]