Due to the limitation of their own transition form, the short-circuit transition and continuous jet transition of ordinary MIG welding have a limited current range, and under the same conditions (referring to the same wire material and diameter), the current used in the pulse jet transition The range is much wider.
It includes both the current range used for short-circuit transition and droplet transition of ordinary MIG/MAG welding, as well as part of the current range used for continuous spray transition. Therefore, both thick and thin parts can be welded.
2) Thin plates can be welded with thicker wires. For example, when 2mm aluminum sheet is welded with ordinary MIG, only 0.8mm diameter welding wire can be used. Such thin welding wire is very soft, and it is impossible to use the push wire feeding mechanism to feed the wire stably. When using pulse MIG welding, p1.6mm aluminum wire can be used.
The wire feeding mechanism can completely stabilize the wire feeding. In addition, the use of thick wire can reduce the manufacturing cost of the welding wire, and the surface area of the welding wire per unit weight is reduced, which greatly reduces the amount of dirt and oxide film brought into the welding seam by the aluminum welding wire, which is conducive to obtaining high welding seam. quality.
3) Materials with strong heat sensitivity can be welded. Due to the many adjustable welding parameters, the MIG pulsed gas shielded welding can control the heat input and weld formation, and is very suitable for welding those metal materials that are sensitive to thermal cycles.
4) Welding of spatial position welds can be carried out. When the welding current exceeds the critical current, the molten droplets can transfer forcefully to the molten pool along the axis of the welding wire.
In addition, the shape and volume of the molten pool can be controlled by adjusting the welding parameters to change the arc shape and energy. In this way, when welding at any position, the droplets will not flow down due to gravity, and welding at all positions can be achieved.
5) It can realize the welding of single-sided welding and double-sided forming butt joints and 100% penetration welding of the root bead of thick plates.
For aluminum alloy workpieces whose thickness is in the range of 3~6mm, the groove is not open for flat welding. If the thickness is greater than 6mm, the V-shaped groove can realize single-sided welding and double-sided forming. For thick steel plates, a V-shaped groove can be opened, no blunt edges are left, and a gap of 2~3mm is left. The first layer can realize single-sided welding and double-sided forming at the vertical welding position.
6) Welding of thick steel plates with narrow gaps is possible. If ordinary MIG jet transfer welding is used, the current greater than 500A must be used for the 2.5~3mm steel wire, which will increase the weld forming coefficient and easily cause cracks. In addition, the nozzle is easy to arc with the side wall of the groove, which destroys the stability of the welding process.
However, using fusion electrode pulse welding, welding frequency f=50~100Hz, welding current 350~450A, Ar+20%CO2 (volume fraction) can overcome the shortcomings of ordinary MIG welding and successfully complete narrow gap welding.