Reasons for sand eyes at the weld of spiral seam submerged arc welded steel pipe

Spiral steel pipe is made by bending the strip steel in a spiral direction through a coiling machine and then welding it through a capacitor double-sided submerged arc. In the process of spiral steel pipe welding production, many galvanized channel steel situations such as leaking welding and misalignment are prone to occur. However, the most difficult to control in these situations is the appearance of sand eyes at the butt weld of spiral steel pipe.

The manufacturer of spiral seam submerged arc welded steel pipe analyzed the reasons for the appearance of sand eyes as follows:

1. The current supplied to the welding gun during welding is too small, the capacitance time is too short, and the welding surface has hardened before the capacitor is fully welded, so there are sand or bubbles that have not been welded through.

2. The strip steel is not well butted when entering the curved knife-shaped arc adjustment, the strip steel is not tightly butted, and there is too much space between the butted strip steel.

3. When butt welding the strip steel, the rust or oxide scale on both sides of the strip steel is not cleaned in time.

4. The production equipment is not repaired and cleaned in time. The dust or dirt on the workbench may accidentally fall into the welding gap of the butt strip.

5. The temperature in the operating workshop is too low or too humid, which affects the temperature and dryness of the welding point.