In the process of the welding gun, molten metal flow to the outside of the weld unmelted metal to form metal flash, called weld flash. Weld flash not only affects the appearance, but also below the weld flash exist welding defects, easily lead to stress concentration, when vertical and horizontal welding easier to produce pipes inside the weld, the effective area of the tube will be reduced, even cause pipeline blockage phenomenon.
The main reason why produce weld flash is that welding flame is too large, welding speed is too slow, weldment assembly gap is too large, wires and welding of mouth is not correct. When performing vertical or overhead welding, should be used smaller flame energy, weldment assembly gap is not too large, wire and welding torch angle should be right.
