Carbon steel pipe is a spiral seam steel pipe with a steel coiled plate as a raw material, which is often extruded and formed by welding with an automatic double-wire submerged arc welding process. The spiral steel pipe feeds the strip steel into the welded pipe unit, and after being rolled by multiple rollers, the strip steel is gradually rolled up to form a round tube blank with an open gap. 3mm, and make the two ends of the welding port flush.