Aluminum alloy welding refers to the welding process of aluminum alloy materials. The aluminum alloy is high in strength and light in weight. The main welding process is manual TIG welding (molten inert gas shielded welding) and automatic MIG welding. The welding effect is related to the base metal, welding wire, protective gas and welding equipment. Let's talk about the common points of wire feeding instability and wire jamming in gas protection welding.
1. Whether the inlet nozzle, the middle nozzle and the outlet nozzle are concentric in a straight line. If it is not in a straight line, it will easily lead to increased wire feeding resistance, resulting in unstable wire feeding.
2. Whether the wire feed wheel is slippery. The first test machine should erase the anti-rust grease and clean the wheel groove regularly, pay attention to the use of soft things to erase. Determine whether the wheel groove is seriously worn: Under normal circumstances, let the wire expose 1/3 of the groove surface, otherwise the wire feed wheel of the corresponding wire diameter should be replaced. The wheel groove must be installed correctly according to the wire diameter.
3. The wire feed ring retaining ring only prevents the rim from falling off during the wire feeding process or the amount of turbulence is too large, and should not be too tight. Otherwise the embedded screws are easy to fall off or loose.
4. Since the wire feeding hose (guide wire tube) is used for a long time, the wire guide tube is filled with dust and iron powder, which also causes a large wire feeding resistance, so it should be cleaned frequently. When the wire guide tube is used for a while, but it is still relatively new, it can be cleaned with compressed air when cleaning (nylon tube can only use this method); when the guide wire tube is worn out, use kerosene, gasoline, alcohol, etc. The solvent is bubbled and then cleaned. When replacing the wire guide tube, select the appropriate hose according to the wire diameter, and cut the length of the hose according to the actual length of the gun, and be sure to remove the burrs at the spiral wire nozzle. In addition, at low speed welding, the filament can be used with a wire guide tube with a diameter of one wire, but the wire guide wire tube is not allowed for the thick wire. For example, the Φ1.2 wire can be used with a Φ1.6 wire guide wire tube, but Φ1. The wire of 6 is not available with the guide wire of Φ1.2. When welding at high speed, the wire feeding tube should be matched strictly according to the diameter of the wire.
5. When the hole of the conductive nozzle is too large, it should be replaced in time, otherwise there will be a problem that the welding process is unstable or the output current is not large enough due to excessive gap conduction. The anti-splash agent can be used in the welding process to prolong the life of the nozzle, and the splash in the gun sheath should be cleaned in time during the welding process. The contact tip of the steel wire should have a diameter larger than the wire diameter of 0.1 to 0.2 mm and a length of about 20 to 30 mm. For aluminum welding wire, it is necessary to increase the diameter of the contact tip (0.2 to 0.3 mm larger than the diameter of the wire) and the length to reduce the wire feeding resistance and ensure reliable electrical conductivity. The aperture of the same wire diameter welded aluminum contact tip is better than that of the welded steel contact tip. Large aperture.
6. The selection of the gun, under the condition of satisfying the working radius, advocates the use of a standard 3m gun. The torch cable can't be bent when it is used (that is, the coil or S-bend can be less than φ400mm). Especially when the torch handle is adjacent to the cable, it must be given high priority and the wire should be kept smooth.
7. The selection of the pressing force should be appropriate. Generally, tighten the pressure adjustment handle on the scale 2~4, not too tight, so as to avoid the wire deformation and increase the wire resistance (especially when welding aluminum and flux core welding), and also accelerate the wear of the wheel groove.
8. The wire feeding plate supports the shaft. Since the shaft is made of aluminum alloy, the plastic hole is worn for a long time during use, and the surface should be cleaned frequently and greased.
9. The direction of rotation of the wire spool should be clockwise and not counterclockwise.