Skills for vertical welding of V-groove plates with argon tungsten arc welding machine

10 Feb 2022

When using a tungsten arc welding machine for vertical welding, compared to flat welding, vertical welding is technically difficult to operate. When the welding machine is working, the adjustment of the welding machine parameters and the use of the welding gun head are also very particular. If the sagging angle of the welding torch head is too small or the arc is stretched too long, it will cause undercut, welding wave bulge, etc. If the wire current is large or the wire current is small, the molten pool will be difficult to control. Thus the welding effect will be affected. Next, we will explain the relevant skills and precautions of the vertical butt welding position of the V-shaped grooved plate in the tungsten argon arc welding.

First, let's talk about the pre-welding preparation for the practical explanation of the V-shaped grooved plate butt vertical welding position. The first one is the size and requirements of the test piece: two steel plates made of Q235-A, the size requirement is 300mmx100mmx8mm, and the bevel angle is 60°±5° (see Figure 1). Clean up the greasy dirt and rust within 20mm of the groove and both sides, until the metallic luster is exposed, and the welding wire is not allowed to be corroded. Second, welding requirements: single-sided welding and double-sided forming. The third, welding material: welding wire is JG-50, 62.4mm, electrode is ф2.0mm cerium tungsten electrode, argon purity is 99.99%. Fourth, welding polarity: DC positive connection. Fifth, pre-welding inspection: carefully check whether the wiring of the welding machine is correct, firm and reliable before welding. Debug the welding parameters as required. At the same time, check whether the xenon arc welding water-cooled and air-cooled systems are blocked or leaked. If any faults are found, they should be resolved immediately. Sixth, tack welding: the assembly gap is 2~4mm, the blunt edge is 1~2mm, and the amount of misalignment is ≤0.6mm. Manual tungsten xenon arc welding is used for tack welding, and the length of the solder joint is 10~15mm. The point joint end is pre-polished into a slope and pre-deformed. The dimensions of the test piece are shown in Figure 2-1, and the welding parameters are shown in Table 2-2.

Then we talk about the operation points and precautions of the practical explanation of the V-shaped groove plate butt vertical welding position. In vertical welding, because the molten pool metal is easy to fall and the weld formation is not easy to control, a smaller welding current and a thinner wire are generally used. The first one, bottom welding: Generally, the inclination angle of the nozzle opposite to the welding direction is 30°~50°. The nozzle is close to the surface of the groove of the weldment to start the arc, and then the arc is used to adjust the position and distance between the tungsten electrode and the root of the weldment groove. Wire feeding starts when the blunt edge of the groove root is partially melted by the arc heat. The angle between the welding gun and the welding wire is generally 90°~110° (see Figure 3). The end position of the welding wire is inside the groove gap and attached to both sides of the gap, so that the welding wire can not be in a state of swaying. The swing amplitude of the nozzle and the tungsten electrode should be determined according to the size of the groove and the gap. The principle is that the root can be fully fused, and the back surface can be formed well. When closing the arc, do not leave the welding torch immediately, wait 5~10s before leaving. Only in this way can it be ensured that there are no defects such as cracks or surface oxidation at the end. Second, fill welding: Fill welding and bottom welding are basically the same, except that the nozzle swings more widely. Of course, the nozzle can also be used to move laterally away from the weldment, but this method is more difficult to operate than leaning on the weldment. Much bigger. The third, cover welding: during cover welding, the torch is raised, relying on the wrist for lateral swing. The cover weld bead should melt 0.5~lmm of the base material of the groove edge to ensure that the weld bead is straight, without undercut, and the weld bead is smooth and beautiful.

In general, it is difficult to use vertical welding for the V-groove butt position of argon tungsten arc welding, but through practical explanation and learning, we can essentially gain the skills and methods of welding technology. Not only that, if you have mastered the welding technology, coupled with the use of our kingsiri tungsten arc welding machine, you can easily get your satisfactory welding results. Our products have many advantages and are innovative products. The pulse arc welding we produce has also obtained a patented product. Whether it is the anti-interference ability of the welding machine, all parameters can be accurately preset, or the new generation of anti-sticking function is adopted, and the anti-sticking problem of the workpiece is solved efficiently, etc., these advantages can help welders to obtain higher quality welding results .

Keywords: welding machine

Originally published 10 Feb 2022, updated 10 Feb 2022.

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