With the continuous development of oil and gas pipelines to large diameters and high pressures, spiral submerged arc welded steel pipes also continue to develop to large diameters, large wall thicknesses and high steel grades. The double wire submerged arc welding process is playing more and more in

1. Small and medium-sized steel bars, wire rods, steel bars, medium-diameter steel pipes, steel wires and wire ropes, etc., can be stored in a well-ventilated material shed, but must be topped and bottomed.2. Some small steels, thin steel plates, steel strips, silicon steel sheets, small-diameter or