Spiral Pipe Welding sulfur segregation

Spiral Pipe sulfur crack (crack caused by sulfur). Sulfur segregation spiral welded steel plates with a strong (especially soft boiling steel) with the segregation of sulfur in the sulfur into the resulting weld metal cracking. The reason is that the melting point of sulfur segregation band containing iron sulfide in the presence of hydrogen and steel. Therefore, in order to prevent this situation generates, uses less sulfur segregation band semi-killed steel or killed steel is also clear efficiency. Secondly, spiral steel pipe weld surface and flux clean and dry is also very necessary. Hot cracking. In submerged arc welding, the weld hot cracking within, particularly in spiral pipe from arcs and arc prone to cracking at the crater. To eliminate this spiral pipe cracks, usually in the arc and arc-quenching plate mounted at, and in the end of the welding coil can be reversed and the spiral welded pipe welded into the stitch welding. Great stress in the weld hot cracking, or when the si weld metal when the most prone to high. Slag involvement. Involved in the welding slag is part remaining in the weld metal welding slag.