The products made by the MIG welding method are mostly steel constructions. We can weld materials with a maximum thickness of 10 mm.
This technology is alternatively called gas metal arc welding and it involves several methods working on the same principles but using different types of additives and shielding gases.
The arc forms between the welding wire and the weldment while the whole process takes place within a protective gas atmosphere. Due to the fact that both wire feeding and gas flow are fully automated, we achieve high productivity. Thanks to the automatization of the process and the use of welding wires and flux-cored wires, the effectiveness is about 90-95 %.
The reason for using gases while welding is the necessity to protect the welded material from air humidity and potential contamination. This protection is achieved by using gas to force out the air. The choice of a shielding gas is determined by the type of material being welded.
Gases can be divided into two categories:
Inert gases (helium, argon or their mixture).
Semi-inert, or active gases (for example carbon dioxide, the mixture of argon and carbon dioxide, and others).
Welding wires can be divided according to their chemical composition and the structure of their core. We often use a solid wire, alternatively a flux-cored wire, although the choice depends on the intended use of the welded material.
A solid wire is usually of the same composition as the weldment and it also contains a chemical additive that cleans the workpiece.
A flux-cored wire, as its name suggests, contains flux granules whose function is similar to electrode coating. The flux used in these wires can be basic, rutile or special flux adjusted to specific requirements. The advantage of a flux-cored wire as compared to a standard wire is that it is better at maintaining a stable arc and makes possible a better penetration into the welded metal. Moreover, the weld looks neater and does not require further working.
Pulsed-current welding is one of the modern welding techniques which can significantly lower heat input into the weld. This also allows very precise gradual transitions between the welded metal and the base material, which is why it is sometimes called the technique of notch-free transitions. This technology works on the principle that in the basic regime the current is rather low, approximately 10 to 15 A, which allows a steady arc. However, the current rises rapidly at specific points, the frequency of these pulses being dependent on the type of the welded material and the weld thickness.