1, in the process of moulding, the steel plate deformation is uniform, the residual stress is small, the surface is not easy to produce scratches.
2、Processing spiral steel pipe has more flexibility in the size range of both diameter and wall thickness.
3、Adopting the most advanced double-sided submerged arc welding process, it can be welded in the best position line of sight.
4, In the steel pipe for 100% quality testing, under strict monitoring and management, effectively guarantee the quality of the product.
Weld treatment should be paid attention to:
1, if the gap is too large, it will cause the neighbourhood effect is reduced, eddy current heat insufficient weld quality inspection combination is not Good cracks.
2, the gap is too small will cause the proximity effect increases, the heat of the weld is too large, so that the weld is burned and damaged
3, the two edges of the billet heated to the welding temperature, after the extrusion rollers under the extrusion, the formation of deep pits, affecting the surface quality of the weld.
4, spiral steel pipe if the extrusion pressure is too small, the number of common crystals formed is small, the strength of the weld metal decreases, and cracking occurs after the force;
5, if the extrusion pressure is too large, will make the molten state of the metal is extruded out of the weld, not only reduces the strength of the weld, but also produces a large number of internal and external burrs, and even cause defects such as weld lap.