Manufacturers of Folding tables need to control the welding temperature when welding stainless steel table legs, so as to ensure the effect of welding. When controlling the temperature, the following points need attention:
1) Arc burning time, in the practice teaching of horizontal fixed and vertical fixed welding of φ57 × 3.5 pipes, arc breaking welding is used. When welding the bottom layer, the frequency of arc breaking and arc burning time directly affect the temperature of the molten pool. The tube wall is thin and the heat capacity of the arc is limited. If you slow down the frequency of the arc to reduce the temperature of the molten pool, it is easy to cause shrinkage. Therefore, you can only control the temperature of the molten pool by the arc burning time. When the weld hole is large, the arc burning time can be reduced to reduce the temperature of the molten pool. At this time, the weld hole becomes smaller, and the internal forming height of the pipe is moderate, so as to avoid a high weld seam inside the pipe or a welding knob.
2) Welding rod angle. When the angle between the welding rod and the welding direction is 90 degrees, the arc is concentrated, the temperature of the molten pool is high, the included angle is small, the arc is scattered, and the temperature of the molten pool is low, such as the bottom of a 12mm flat welding seal, the angle of the electrode: 50- 70 degrees, which reduces the temperature of the molten pool, and avoids welding bumps or rising on the back.
3) Strip transport method. The temperature of the molten pool of the circle-shaped strip is higher than the temperature of the crescent-shaped strip, and the temperature of the crescent-shaped strip is higher than the temperature of the molten pool of the zigzag strip. And, with the amplitude of the swing and the pauses on both sides of the groove, the temperature of the molten pool was effectively controlled, so that the size of the molten holes was basically the same, and the probability of no formation of welding knobs and burn-through at the root of the groove was reduced. The improvement makes the single-sided welding and double-sided forming of the flat butt welding of the plates no longer difficult.
4) Welding current and electrode diameter: Welding current and electrode diameter are selected according to the spatial position of the weld and the welding level. When welding is started, the selected welding current and electrode diameter are larger, and the vertical and horizontal positions are smaller. For example, the sealing layer of 12mm flat butt welding uses φ3.2mm electrode, welding current: 80-85A, filling, cover layer uses φ4.0mm electrode, welding current: 165-175A, reasonable selection of welding current and electrode diameter It is easy to control the temperature of the molten pool, which is the basis of weld formation.