Fish scale welding is a kind of welding process, because its welding plane is like fish scale. The main is to select the welding point, electrify, knock out the arc with the welding rod head, so that the welding flux in the welding rod melts, and then swing the welding clamp around a small range, so that the welding center evenly melts in the welding position, the general welding effect is good like fish scale, so it is called fish scale welding. Fish scale welding is considered to be the most advanced welding technology in the world.
TIG welding itself belongs to the open arc operation can observe the shape and flow of the molten pool, much better than electrode arc welding;
Control of welding hand stability is the biggest key to avoid shivering and burning of the dock pole resulting in tungsten inclusion in the molten pool. The control method can only be used to hold the welding gun index finger to support the welded pipe or plate. The length of the tungsten pole can be selected according to the depth of the groove, generally 3-5mm;
The wire transport method can be selected according to the size of the groove. When the groove Angle is small, the wire can be placed in the middle of the tank and continuously sent into it. When the groove is larger, both sides of the point can be used to feed the wire (to be quite skilled, avoid touching the dock pole), the welding gun moved around to make the edge of the fusion is good;
As for the full fish scale pattern on the surface, according to the scoring standard of the examination competition, the residual height of TIG weld is generally 0-2mm, and the surface is smooth without bite, porosity, crack and fusion.
General flat butt welding electrode swing method has zigzag, crescent, triangle, ring and figure eight. The key of vertical fillet welding is how to control the molten pool metal. The electrode should swing up and down rhythmically according to the cooling condition of the molten pool metal. In the welding process, when the first molten pool appears after arc initiation, the arc should be raised quickly. When the molten pool is instantly cooled into a dark red point, the arc is lowered to the arc pit, and the droplet falling overlaps with the molten pool in front by 2/3, and then the arc is raised. This rhythmically forms a fillet weld.