The strength of the spiral tube is generally higher than that of the straight seam welded pipe. It can use a welded pipe with a larger diameter of the billet material, and can also use the same width to produce a tube with different welded pipes with different billet production pipes.However, compared with the same length of the same length, the length of the weld is increased by 30 ~ 100%, and the production speed is lower.Therefore, most of the smaller -caliber welded pipes are welded with straight seams, and most of the large -caliber welded pipes are mostly spiral welded.After the large -diameter spiral steel pipe manufacturer, the two edges of the spiral steel pipe billet were heated to the welding temperature. Under the squeezing roller, the common metal grains penetrated and crystallized, and finally a firm welded joint.
If the pressure is too small, the number of common crystals is small, the intensity of the weld metal decreases, and it will crack after the force; if the pressure is too large, the metal of the melting state will be squeezed out of the weld, which will not only reduceThe intensity of welds will also produce a large number of internal and external burrs, and even defects such as welding seams.
The impedance is a special magnetic rod for a spiral steel pipe. The cross -area of the impedance should usually not be less than 70%of the sectional area of the inner diameter of the steel pipe., To produce a neighboring effect, the vortex heat set is near the edge of the pipeline welding seam, so that the edge of the pipe billet is heated to the welding temperature.The impedance is dragged in a tube with a wire, and its heart position should be relatively fixed in the position near the squeeze roller.During the boot, due to the rubbing of the tube, the impedance device was friction with the inner wall of the tube.
The large -caliber spiral steel tube spiral steel pipe is often replaced.
(1) The raw materials are steel rolls, welded wires, and solder.Strict physical and chemical tests must be passed before the investment.
(2) Bring steel head and tail docking, single -silk or double -wire buried arc welding, and use automatic buried arc welding to replenish welding after being rolled into a steel pipe.
(3) Before forming, the tissue is clear, cut, and planed, and the surface is cleaned and transported on the surface.
(4) Use the electric connection point pressure gauge to control the pressure of the oil cylinder on both sides of the conveyor to ensure the smooth transportation of the steel.
(5) Use external or internal control rollers.
(6) The weld gap control device is used to ensure that the weld gap meets the welding requirements. The pipe diameter, the error edge amount and the weld gap are strictly controlled.
(7) Internal welding and external welding are used in the United States Lincoln welding machine for single or double wire buried arc welding to obtain a stable welding specification.
(8) The welded welded seams are checked by continuous ultrasonic automatic injuries online to ensure the non -destructive detection coverage of the spiral weld.If there are defects, automatically call the police and spray the mark, the production workers adjust the process parameters at any time to eliminate the defects in time.
The advantages of thick wall spiral steel pipe pipes, the strong oxide film on the surface of the thick wall steel pipe makes all water quality of stainless steel, including soft water, has excellent corrosion resistance.Extracting performance.
