The Cause of the Welds in Trachoma

Spiral pipe is strip by roller, spiral spiral direction, and then through the capacitor for double submerged arc welding. Spiral welded pipe production process, prone to welding and missed welding many wrong edges and so on. However, under these conditions, trachoma is the most difficult to handle spiral steel butt weld.
The so-called trachoma: refers to the weld or weld surface welding process, there is no complete penetration of particles or bubbles, as well as the surface of the weld pit shape. Trachoma occurs because of the following:
1, welding torch in the welding current is too small, the capacitor is too short, when the welding surface hardening, the capacitor has not been completely and completely welded, so there is no penetration of sand or bubbles.
2, for the curvature of the machetes bar, there is no good butt, butt is not fully matched, there is too much gap between the tailor welded plate.
3, when the strip on both sides of the steel butt did not promptly clean the edge of the strip with rust or scales.
4, production equipment is not timely maintenance and cleaning. Workbench dust or dirt, patchwork in the butt welding gap.
5, workshop temperature is too low or too wet, affecting the solder joint temperature and dryness.