Causes of trachoma in the weld of spiral seam submerged arc welded steel pipe
The spiral steel pipe is made by bending the steel strip in the spiral direction through the coiling machine, and then through the double-sided submerged arc welding of the capacitor. In the production process of spiral steel pipe welding, many cases of galvanized channel steel such as missing welding and wrong edges are prone to occur. However, the most difficult thing to grasp in these situations is the occurrence of trachoma at the butt weld of the spiral steel pipe.
Spiral seam submerged arc welded steel pipe analyze the causes of trachoma as follows:
1. During the welding process, the current supplied to the welding gun is too small, and the capacitor time is too short. When the capacitor is not completely welded, it appears to be hardened outside the welding, so there are sand or bubbles that have not been welded through.
2. When the strip steel enters the scimitar-shaped adjustment arc, it is not properly butted, the strip steel is not tightly connected, and there is an excessively large open space between the butt steel strips.
3. When butt-welding the strip steel, the rust or oxide scale on both sides of the strip steel was not cleaned up in time.
4. The production equipment was not repaired in time. The dust on the workbench may be dirty and fall into the welding gap of the butt strip by mistake.
5. The temperature in the operating workshop may be too low or too humid, which will affect the temperature and dryness of the solder joints.