1. During the welding process, the current supplied to the welding torch is too small, and the capacitor time is too short. When the capacitor is not fully welded, the welding surface has hardened, so there are sand grains or air bubbles that have not been fully welded.
2. When the strip enters the arc of the machete shape adjustment, the butt joints are not well done, the butt joints of the strips are not tightly sealed, and there is an excessively large space between the butt strips.
3. When butt welding the strip, the rust or oxide scale on both sides of the strip is not cleaned in time.
4. The production equipment is not repaired in time. The dust on the workbench may be dirty and fall into the welding gap of the butted strip by mistake.
5. The temperature in the operation workshop is too low or too humid, which affects the temperature and dryness of the solder joints.