Main process features of spiral steel pipe

The main process features of spiral steel pipe:

a. During the forming process, the steel plate deforms evenly, has small residual stress, and does not produce scratches on the surface. The processed spiral steel pipe has greater flexibility in the size range of diameter and wall thickness, especially in the production of high-grade thick-walled pipes. It has advantages that other processes cannot match in terms of small and medium-diameter thick-walled pipes, and can meet the needs of users. There are more requirements for spiral steel pipe specifications.
b. The double-sided submerged arc welding process can be used to achieve welding at the optimal position, which is less likely to cause defects such as wrong edges, welding deviation and incomplete penetration, and it is easy to control the welding quality.
c. The quality inspection of steel pipes ensures that the entire process of steel pipe production is under effective detection and monitoring, effectively ensuring product quality.
d. All equipment in the entire production line has the function of networking with the computer data collection system to realize real-time transmission of data, and the control room monitors the technical parameters in the production process.

The processing of spiral welds mainly includes the following two aspects:

1. If the gap is too large, the adjacent effect will be reduced, the eddy current heat will be insufficient, and the inter-crystal bonding of the weld will be poor, resulting in lack of fusion or cracking.
2. If the gap is too small, the adjacent effect will increase and the welding heat will be too high, causing the weld to burn out; or the weld will form a deep pit after being extruded and rolled, affecting the surface quality of the weld. After the two edges of the tube blank are heated to the welding temperature, they are squeezed by the extrusion roller. Common metal grains are formed to penetrate and crystallize with each other, eventually forming a strong weld.

If the extrusion force of the spiral steel pipe is too small, the number of common crystals formed will be small, the strength of the weld metal will decrease, and cracking will occur after stress; if the extrusion force is too large, the molten metal will be squeezed out of the weld, It not only reduces the strength of the weld, but also produces a large number of internal and external burrs, and even causes defects such as welding laps.