Year1
- 材质：
- Q235
Production material: QQRQQD. The main pressure-bearing parameters are / , which is the yield strength and which is the wall thickness. Submerged arc welding has developed into double-wire submerged arc welding and multi-wire submerged arc welding, and the efficiency has been further improved.
Straight seam steel pipe in English ( ), general welded pipe: General welded pipe is used to transport low-pressure fluid. Made of Q, Q, Q steel and QB plain carbon. It can also be manufactured using standard models that are easy to weld and mild steel. Steel pipes are subject to hydraulic pressure, bending, flattening and other experiments, and have certain requirements for surface quality. The delivery length is usually m, and delivery of fixed length (or multiple lengths) is often required. The specifications of welded pipes are expressed in nominal diameter (millimeters or inches). The nominal diameter is different from the actual. According to the specified wall thickness, there are two kinds of welded pipes: ordinary steel pipes and thickened steel pipes.
Submerged arc welding process
Plate detection: After the steel plates used to manufacture large-diameter submerged arc welded straight seam steel pipes enter the production line, they are first subjected to full-plate ultrasonic inspection
. Edge milling: Through edge milling The machine performs double-sided milling and cleaning on both edges of the steel plate to achieve the required plate width, plate edge parallelism and groove shape
. Pre-bending the edge: Use a pre-bending machine to pre-bend the plate edge to make the plate edge have Curvature that meets the requirements
. 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: join the formed straight seam welded steel pipes and use gas shielded welding (M) for continuous welding
. Internal welding: use tandem multi-wire submerged arc welding (up to four Wire) is welded on the inside of the straight seam steel pipe
. External welding: tandem multi-wire submerged arc welding is used to weld on the outside of the straight seam submerged arc welded steel pipe
. Ultrasonic inspection Ⅰ: on the inside and outside of the straight seam welded steel pipe The weld and the base metal on both sides of the weld are inspected
. Radiographic inspection I: % radiographic industrial television inspection is performed on the internal and external welds, and an image processing system is used to ensure the sensitivity of flaw detection
. Expand Diameter: Expand the diameter of the entire length of the submerged arc welded straight seam steel pipe to improve the dimensional accuracy of the steel pipe and improve the distribution of internal stress in the steel pipe
. Hydraulic test: The expanded steel pipe is tested on a hydraulic testing machine. Inspect one by one to ensure that the steel pipes meet the test pressure required by the standard. The machine has automatic recording and storage functions
. Chamfering: The steel pipes that have passed the inspection will be processed at the pipe end to achieve the required pipe end bevel size
/> . Ultrasonic inspection II: Conduct ultrasonic inspection one by one again to check the defects that may occur after diameter expansion and hydraulic pressure of the straight seam welded steel pipe
. Radiographic inspection II: Carry out on the steel pipe after diameter expansion and hydraulic pressure test Radiographic industrial TV inspection and pipe end weld film
. Pipe end magnetic particle inspection: This inspection is performed to find pipe end defects
. Anti-corrosion and coating: Qualified steel pipes are anti-corrosion and coated according to user requirements. layer.
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