The current advanced SSAW (spiral seam submerged arc welded steel pipe) steel pipe production process has undergone a series of optimizations and improvements on the basis of traditional processes, mainly including the following processes:

1. Raw material preparation: Select high-quality hot-rolled steel coils as raw materials, and equip them with suitable welding wires and fluxes. The raw materials need to undergo strict physical and chemical testing to ensure their performance meets production requirements.

2. Strip steel processing:

Leveling: The strip steel is leveled using a multi roll leveling machine to eliminate its original curling and ensure its flatness during subsequent processing.

Edge milling: The edge milling machine is used to process the two sides of the strip steel to achieve the specified width and groove shape, ensuring welding quality.

Surface cleaning: Clean the surface of the strip steel to remove impurities such as oil and rust, in order to improve the bonding strength of welding.

3. Forming welding:

Pre bending: Pre bending treatment is carried out on the head and tail of the strip steel to better enter the forming machine and ensure the initial forming quality of the steel pipe.

Spiral forming: Using a forming machine to spiral roll strip steel into steel pipes, ensuring the dimensional accuracy and roundness of the steel pipes by controlling the forming angle and speed. During the forming process, internal and external control rollers are used to control the shape of the steel pipe.

Welding: Advanced double wire or multi wire submerged arc welding technology is used to weld the inner and outer welds of steel pipes. During the welding process, strict control of welding parameters such as current, voltage, welding speed, etc. is necessary to achieve stable welding specifications and good weld quality. At the same time, use a weld seam tracking device to ensure the accurate position of the weld seam.

4. Weld seam inspection:

Online ultrasonic testing: Using an online continuous ultrasonic automatic flaw detector to perform 100% inspection on the weld seam, timely detecting defects such as cracks, pores, slag inclusions, etc. in the weld seam. Once a defect is detected, the equipment will automatically sound an alarm and mark it, and production workers can adjust process parameters or make repairs in a timely manner.

X-ray inspection: X-ray television or film inspection is carried out on the weld seam to further detect the quality inside the weld seam, ensuring that the fusion and internal defects of the weld seam meet the standard requirements.

5. Cutting to length: Use an air plasma cutting machine to cut the steel pipe into the specified length, ensuring the length accuracy of the steel pipe.

6. Hydrostatic test: Conduct a hydrostatic test on each steel pipe to inspect its sealing and strength. The test pressure and time are strictly controlled according to relevant standards, and the test parameters are automatically controlled and recorded through a steel pipe hydraulic microcomputer detection device.

7. Pipe end processing: Process both ends of the steel pipe, including turning, chamfering, etc., to ensure that the verticality, bevel angle, and blunt edge size of the pipe end meet the requirements, facilitating the connection and installation of the steel pipe.

8. Final inspection: Conduct a comprehensive visual inspection, dimensional measurement, and performance test on the steel pipe, including its outer diameter, wall thickness, straightness, weld appearance, as well as its mechanical and chemical properties. Only steel pipes that meet the standard requirements in all indicators can be judged as qualified products.

9. Anti corrosion treatment: According to customer needs, anti-corrosion treatment is carried out on steel pipes, such as coating with anti-corrosion coatings, wrapping with anti-corrosion layers, etc., to improve the corrosion resistance and service life of steel pipes.

10. Packaging labeling: Qualified steel pipes are packaged, usually protected by bundling, oiling, and other methods, and then labeled according to customer requirements, indicating the specifications, material, length, production batch, and other information of the steel pipes.

In addition, some advanced production processes also use computer control systems to monitor and manage the entire production process, achieving automated production and quality control, and improving production efficiency and product quality stability. At the same time, continuous research and improvement are being conducted in areas such as raw material selection, welding material development, and process parameter optimization to further enhance the performance and quality of SSAW Steel Pipes. For example, Shandong Shengli Steel Pipe Co., Ltd.'s annual production of 360000 tons of high-grade oil and gas transmission pipe pre precision welding production technology is the first SSAW production line in China to fully introduce international advanced pre precision welding equipment and process technology, and has the ability to produce high-grade oil and gas transmission pipelines.

Here are some other advanced aspects of SSAW steel pipe production process:

Automation and Information Control

Production process automation: Using an automated control system to achieve precise control over various links such as strip steel conveying, forming, welding, and inspection. For example, through PLC (Programmable Logic Controller) and sensors, real-time monitoring and adjustment of the position, speed, welding parameters, etc. of the strip steel are carried out to ensure the stability and consistency of the production process, reduce the impact of human factors on product quality, and improve production efficiency and product qualification rate.

Quality monitoring informatization: Using information technology to establish a quality monitoring system, real-time collection, analysis, and storage of various data in the production process. By using online detection equipment to obtain ultrasonic, X-ray and other testing data of welds, as well as parameters such as the size and performance of steel pipes, and transmitting these data to the central control system for analysis and processing, once quality problems are found, they can be quickly located and corresponding measures can be taken. At the same time, it is also convenient to trace and statistically analyze product quality, providing a basis for process improvement.

Application of New Welding Materials and Processes

High performance welding materials: Develop and apply new types of welding wires and fluxes to improve the mechanical properties and corrosion resistance of welds. For example, using welding wires containing alloy elements such as nickel and chromium, as well as fluxes with special formulations, can effectively improve the microstructure and properties of welds, making them perform better in terms of high strength, high toughness, and corrosion resistance, meeting the quality requirements of steel pipes in different application scenarios.

Advanced welding processes: In addition to traditional submerged arc welding technology, some companies are also exploring and applying other advanced welding processes, such as laser arc hybrid welding technology. This technology combines the high energy density of laser welding and the stability of arc welding, which can achieve more efficient and high-quality welding, improve the penetration depth and width of the weld seam, reduce welding defects, and also reduce welding heat input and deformation, further improving the quality and production efficiency of steel pipes.

Green Manufacturing and Energy saving Technologies

Energy saving equipment and technology: Adopt energy-saving equipment in the production process, such as high-efficiency motors, energy-saving heating furnaces, etc., to reduce energy consumption. At the same time, optimize production process parameters, arrange production processes reasonably, and reduce unnecessary energy waste. For example, by improving the heating process, precisely controlling the heating temperature and time, and enhancing energy utilization efficiency; By adopting frequency conversion speed regulation technology, the motor speed is adjusted according to the actual operating conditions of the equipment to reduce energy consumption.

Environmental protection measures and resource recycling: Strengthen environmental protection measures to reduce pollutant emissions during the production process. If efficient smoke and dust purification equipment is used to purify the smoke and dust generated during the welding process to meet emission standards; Classify, recycle, and reuse the waste and scraps generated during the production process, reduce raw material consumption, achieve resource recycling, reduce environmental impact, and meet the requirements of sustainable development.

Improvement of Pipe End Processing Technology

High precision pipe end machining: Advanced pipe end machining equipment and processes are used to achieve high-precision machining of pipe ends. For example, using CNC lathes, milling machines, and other equipment to perform machining operations such as turning, chamfering, and boring on pipe ends, ensuring the dimensional accuracy and surface quality of pipe ends, and meeting the high-precision requirements of steel pipe connections. At the same time, automatic centering and clamping devices are used to ensure the concentricity and perpendicularity of the pipe end processing, improving the connection and sealing performance of the steel pipe.

Anti corrosion and protection of pipe ends: Strengthen the anti-corrosion and protection treatment of pipe ends to improve their corrosion resistance and wear resistance. In addition to anti-corrosion treatment of the entire steel pipe, special anti-corrosion coatings or protective measures are also applied to the pipe ends, such as coating thick slurry anti-corrosion coatings, installing pipe end protective sleeves, etc., to prevent corrosion and damage to the pipe ends during transportation, storage, and use, ensuring the overall quality and service life of the steel pipe.