Year1
- 规格：
- 88*3
- 标准：
- GB3091
Submerged arc welding process
. Plate probe is used to manufacture large-diameter submerged arc welded straight seam steel pipes. After the steel plates enter the production line, they are first subjected to full-plate ultrasonic inspection
. The milled edges are processed by an edge milling machine. The two edges of the steel plate are double-sided milled to achieve the required plate width, plate edge parallelism and groove shape
. Pre-bending the edge uses a pre-bending machine to pre-bend the plate edge so that the plate edge has the required curvature.
. Forming: First, half of the pre-bent steel plate is stamped and pressed into shape through multiple steps on the forming machine, and then the other half of the steel plate is similarly bent and pressed into shape, and finally the shape of the opening is formed
. Pre-welding joins the formed straight seam welded steel pipes and uses gas shielded welding for continuous welding
. Internal welding uses tandem multi-wire submerged arc welding (up to four wires) to weld the inside of the straight seam steel pipe
br/> . External welding uses longitudinal multi-wire submerged arc welding on the outside of the straight seam submerged arc welded steel pipe
. Ultrasonic inspection Ⅰ is carried out on the internal and external welds of the straight seam welded steel pipe and the base metal on both sides of the weld. Inspection
. Radiographic inspection Ⅰ Conduct % radiographic industrial television inspection of internal and external welds, using an image processing system to ensure the sensitivity of flaw detection
. Diameter expansion The entire length of the submerged arc welded straight seam steel pipe is expanded. In order to improve the dimensional accuracy of the steel pipe and improve the distribution of internal stress in the steel pipe
. The hydraulic test is to inspect the expanded steel pipes one by one on a hydraulic testing machine to ensure that the steel pipes meet the test pressure required by the standard. This machine With automatic recording and storage functions
. Chamfering will process the pipe end of the qualified steel pipe to achieve the required pipe end bevel size
. Ultrasonic inspection II will conduct ultrasonic inspection one by one again to check the straight seams Possible defects in welded steel pipes after diameter expansion and hydraulic pressure
. Radiographic inspection II conducts radiographic industrial television inspection and pipe end weld photography on steel pipes after diameter expansion and hydraulic pressure testing
. Pipe end magnetic powder Inspection This inspection is carried out to detect pipe end defects
. Steel pipes that have passed the anti-corrosion and coating requirements will be anti-corrosion and coated according to user requirements.
Applications Straight seam steel pipes are mainly used in water supply projects, petrochemical industry, chemical industry, electric power industry, agricultural irrigation, and urban construction. Used for water supply and drainage for liquid transportation. For gas transportation, coal gas, steam, and liquefied petroleum gas are used. It is used as piling pipes for structures, pipes for bridges, wharves, roads, building structures, etc.
High-frequency welded straight seam steel pipe specifications The following straight seam high-frequency welded steel pipes have the characteristics of relatively simple process and rapid continuous production. They are widely used in civil construction, petrochemical, light industry and other departments. It is mostly used to transport low-pressure fluid or be made into various engineering components and light industrial products. The straight seam high-frequency welded steel pipe has advanced forming technology, reliable quality, good welding position, stable welding parameters, fast welding speed and high output. The equipment and technology of the entire production line are at the current international level. Product Features: Straight seam high-frequency welded steel pipe has small rebound and small residual stress during the forming process. The deformation hardening effect is small, and the geometric dimensions after rounding are accurate, which is beneficial to ensuring construction and welding quality. The straight seam high-frequency welded steel pipe weld bead has a good shape and is not prone to defects such as undercuts and misalignment of internal and external welds. The straight seam steel pipe weld bead is distributed at one point on the circumference, so the weld can be placed at a favorable position according to the usage requirements. Straight seam welded steel pipes are made by rolling long strips of steel strips of certain specifications into round tubes through high-frequency welding units and welding straight seams. Welded steel pipes should be subjected to mechanical performance tests, flattening tests and expansion tests, and To meet the requirements specified in the standard. The steel pipe should be able to withstand a certain internal pressure. If necessary, a pressure test should be carried out to ensure that there is no leakage for one minute. It is allowed to use eddy current flaw detection method instead of hydrostatic test. Eddy current flaw detection is performed in accordance with the "Eddy Current Flaw Detection Inspection Method for Steel Pipes" standard. The eddy current flaw detection method is to fix the probe on the frame, keep a distance between the flaw detection and the weld, and rely on the rapid movement of the steel pipe to conduct a comprehensive scan of the weld. The flaw detection signal is automatically processed and automatically sorted by the eddy current flaw detector to achieve flaw detection. the goal of.
Songti high-frequency welding is based on the principle of electromagnetic induction and the skin effect, proximity effect and eddy current thermal effect of AC charges in the conductor, so that
Songti weld
Songti edge steel is locally heated to melt state, through the extrusion of the roller, the butt weld is inter-granularly bonded, thereby achieving the purpose of welding. High-frequency welding is a kind of induction welding
(or pressure contact welding). It does not require weld filler and has no welding spatter.
Songti welding heat affected zone
Songti is narrow and the welding shape is beautiful. Due to its advantages such as good welding mechanical properties, it is widely used in the production of steel pipes.
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