How to select the most suitable welding method from MIG,MGA,MMA and TIG?
There are 5 factors which can influence welding result. You can select the suitable welding type according to real requirement.
1. Welding Speed
In the case of mass production in a short time, speed is the key point in terms of cost-effectiveness. The high welding speed means that the heat-affected zone on the component is smaller. This area is formed in the weld area, the input heat will reduce the metal performance. Heat can locally harden the base metal, make it brittle, cause cracks or breaks, and reduce tensile strength. Therefore, it is important to minimize the amount of heat entering the base metal.
The MIG/MAG welding process have a fast welding speed, good welding quality and wide range of functions.
Application welding case: dynamic loads such as bridge girders, train carriage or parts of vibrating machinery.
2. Welding Environment
The method of welding process also depends on the influence of the environment. Whether the workpiece is exposed to the outdoor environment, or whether it can be welded while protecting it from wind and weather.
The TIG and MIG/MAG processes require separately supplied gas to provide protective shielding gas. This can only be ensured in enclosed spaces or by shielding components, so that the supplied protective gas will not be blown away.
For outdoor welding environment, manual arc welding is best. The burned coating forms protective gas and slag to protect the melt from chemical reactions with ambient air.
Manual arc weld does not require shielding gas, so this method can also be used outdoors.
3.Weld Seam Appearance
Since the weld seams are clearly visible, a perfect appearance is essential. We usually require a smooth fish-scale weld appearance and extremely fine texture. This can only be achieved by TIG welding or special functions of the MIG/MAG method, such as MIG/MAG seam weld or CMT. In manual arc weld, the welding appearance depends on the type of electrode used.
Use TIG welding method to obtain a characteristic weld appearance.
Need to use special functions to reproduce fish-scale weld. The Fronius MIG/MAG-CMT CycleStep is used here.
4. Welding Quality
TIG welding has the best mechanical properties. TIG is the first choice where the quality of welds is paramount. MIG/MAG welds can also reach very high quality. High-quality TIG welds require high purity of the joint edges before welding. In order to use the TIG, they must be completely clean:free of rust, oil, grease and any other impurities.
The TIG welding method can produce extremely high-quality welds, but requires extremely clean and low welding speed.
5. Thickness of Workpiece
In addition to theese above-mentioned requirements for the welding, workpiece thickness also plays a certain role in the selection of the welding method. Workpieces thickness less than 1 mm cannot be welded with welding rods, but if the workpiece thickness is bigger than 4 mm, TIG welding is considered uneconomical. On the other hand, the MIG/MAG welding method can be used for any material from ultra-light steel to solid steel.