Controlling the stability of the hand during welding is the biggest key to avoid shaking and burning the dock electrode, resulting in tungsten inclusion in the molten pool. The control method can use the forefinger to hold the welding gun to support the welded pipe or plate. The extension length of tungsten electrode can be selected according to the groove depth, generally 3-5 mm, and the wire feeding method can be selected according to the groove size. When the bevel angle is small, the welding wire can be placed in the middle of the molten pool and continuously fed. When the groove is large, wire can be fed from both sides (be quite skilled to avoid touching the butt rod), and the welding gun moves left and right to make the edge fuse well. For fish scales with full surface, according to the scoring standard of the assessment competition, the residual height of TIG weld is generally 0-2MM, and the surface is smooth without undercut, porosity, crack and fusion. Generally, the covered electrode swing modes of flat welding are sawtooth, crescent, triangle, ring and figure-eight! The key of vertical fillet welding is how to control the molten pool metal, and the covered 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 striking, the arc should be struck quickly. When the molten pool instantly cools to dark red spots, the arc descends to the arc pit, and the droplet overlaps the previous molten pool by 2/3 when it falls, and then arcs. Therefore, the vertical fillet weld is formed rhythmically.
Judging from the weld scale, the quality is good or bad: the rough weld line is obviously uneven weld appearance, and the arc swing is unstable during welding. The smaller the weld appearance line, the more stable the arc swing during welding.