Because of the long distance and long-distance natural gas pipeline, the geographical environment is complex. Therefore, there are many factors influencing the normal service of the pipeline, but the main factors can be divided into the external environment and the quality of the pipeline itself. The quality of steel pipe is an important factor affecting the quality of the pipe, and the main factors affecting the quality of the steel pipe, including the quality of steel used in steel and steel pipe manufacturing process.
Quality of steel plate
The characterization parameters related to steel quality include steel grade, chemical composition, metallographic structure and mechanical properties.
Forming method
The quality of forming the ultimate impact of the final pipe residual stress distribution, springback and cross-section size accuracy.
Welding process
Key Process of Welding Submerged Arc Welding Straight - seam Steel Tube Production. Welding parameters, such as welding material, welding speed, welding current, welding voltage, welding wire arrangement, pitch and inclination, affect the performance of the weld.
Expansion
Expansion is the use of hydraulic pressure or mechanical force from the inner wall of the steel pipe to expand the steel radial outward a process that can eliminate the formation of steel pipe and welding residual stress generated during the process to improve the accuracy of steel pipe geometry and strength. The expanding diameter, the pressure of hydraulic expansion, the number of fan-shaped blocks in mechanical expanding, the speed of expanding and the conditions of lubricating have influence on the quality of expanding diameter.
Inspection during production
In the steel pipe production process, the need for material physical and chemical properties of the test, ultrasonic testing, X-ray detection, magnetic particle testing and other tests. The strict implementation of these test items can be monitored at any time pipe production, quality problems and timely feedback and treatment to ensure the quality of steel production.
