45° fixed tube electrode arc welding operation detailed

1) Weld the bottom layer In order to achieve single-sided welding and double-sided forming, breakdown welding method should still be used for the bottom layer. During the breakdown welding of the inclined pipe, the molten pool should always be kept in a horizontal state. The diameter of the electrode is 3.2mm and the welding current is 90~120A. Because the geometric shape of the weld is not easy to control, the inner wall is easy to appear convex and concave, the upper side of the weld is easy to bite, and the surface of the weld is rough and uneven. During the operation, the whole weld is divided into two halves: the front and the back. The arc starting point is at the uptilt welding position. The long arc is first used to preheat the groove root, and then the arc is depressed to penetrate the blunt edge and form the melting hole. When the “poof” breakdown is heard, the liquid metal is given and the strip is welded. If the molten pool temperature is too high to cause the liquid metal to fall, it should be appropriate to swing the electrode to control. 2) Welding of the remaining layers The oblique oval strip method is adopted. When transporting the strip, the arc of an elliptical circle is drawn diagonally on the upper groove surface to the edge of the lower groove surface, and then the arc is returned to the edge of the upper groove surface for transporting the strip, and the molten pool is pressed 2~3mm on the upper and the lower groove respectively, so on and so on until the welding is completed. The welding method of the joint, the upper joint is similar to the joint of the flat welding position of the horizontal fixed pipe; There are three lower joint methods: ① The first joint method The front half-round weld starts arc from the middle of the weld pass of the front welding layer at the positive oblique position of the lower joint; Then the arc is pulled down to the groove surface or edge (cover layer welding), and over the center line 10~ 15mm, the right ring, small oval strip, gradually increase the oval to the groove surface or edge transition, so that the first half of the weld head is inclined triangle, and the formation of the groove is high and the groove is low slope; Then carry the right elliptic strip and weld, keep the molten pool in a horizontal ellipse, and weld to the upper joint. To the upper joint to make the weld is oblique triangle, and 10~ 15mm across the center line. After half a circle once half a circle weld before beginning in middle layer of weld arc, arc heating bead after 1 ~ 2 s, and then in farah uphill mouth with oblique elliptic thin deposited metal to downhill mouth surface or edge of the oblique triangle beginning of the first half of the circle weld completely cover, and then used the left syncline oval shipment original welding molten pool is horizontal. When welding to the upper joint, gradually reduce the oval to carry the strip, and the first half of the weld end smooth contact. ② The second joint method The lower beginning of the first half turn of the weld starts from the upper groove through the center line 0~15mm. Then, the right oblique pull to the lower groove, and the oblique oval strip method is used to make the beginning of the upper sharp Angle slope. The latter half of the weld starts from the lower part of the sharp Angle, and is welded with the left oblique method from small to large to the upper joint. ③ The third joint method The method is suitable for the joint of large diameter and thick wall pipe. First, start the arc on the bottom groove surface, connect the arc operation, press the groove edge for welding, so that the edge melting 2~3mm. Then horizontally pull the welding rod to the upper groove, so that the upper groove surface edge melting 1.5~2mm, welded into a triangle or trapezoidal base. The first half turn and the second half turn of the two welds are welded from the upper groove surface to the lower groove surface with inclined oval strip, cover the edge of the triangular base, and then weld until the upper joint.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods