Straight seam steel pipe can be divided into high-frequency straight seam steel pipe and submerged arc welding straight seam steel pipe according to the production process. Submerged arc welding straight seam steel pipe is divided into UOE, RBE, JCOE steel pipe and so on according to its different forming methods. The following describes the most common straight seam submerged arc welding forming process.

1. Plate testing: After the steel plate used to manufacture large-caliber submerged arc welded straight seam steel pipe enters the production line, the whole plate is first inspected by ultrasonic;

2. Edge milling: double-sided milling of the two edges of the steel plate through the milling machine to achieve the required plate width, plate edge parallelism, and groove shape;

3. Pre-bending edge: use a pre-bending machine to pre-bend the plate edge, so that the plate edge has the curvature in line with the requirements;

4 molding: in the JCO molding machine, first of all, half of the steel plate after pre-bending after multiple step stamping, is pressed into the "J" shape, and then the other half of the steel plate is also bent, pressed into the "C" shape, and finally form the opening of the "O" shape

5. Pre-welding: make the formed straight seam welded steel pipe seam and use gas welding (MAG) for continuous welding;

6. Internal welding: longitudinal multi-wire submerged arc welding (up to four wires) is used to weld the inside of the straight seam steel pipe;

7. External welding: longitudinal multi-wire submerged arc welding is used to weld the outside of the straight seam submerged arc welding steel pipe;

8. Ultrasonic inspection ⅰ: 100% inspection of the internal and external welds of the straight seam welded steel pipe and the base metal on both sides of the weld;

9. X-ray examination ⅰ: 100% X-ray industrial television inspection of the inside and outside welds, using an image processing system to ensure the sensitivity of flaw detection;

10. Diameter expansion: the full length of submerged arc welded straight seam steel pipe is expanded to improve the dimensional accuracy of the steel pipe and improve the distribution of stress in the steel pipe;

11. Hydrostatic test: in the hydrostatic test machine, the steel pipe after expanding diameter are inspected one by one to ensure that the steel pipe meets the standard test pressure, the machine has automatic recording and storage function;

12. Chamfering: the pipe end is processed after passing the inspection to reach the required pipe end groove size;

13. Ultrasonic inspection ⅱ : once again one by one ultrasonic inspection to check straight seam welded steel pipe in diameter expansion, water pressure may produce defects;

14. X-ray inspection ⅱ: X-ray industrial television inspection and pipe end weld film of steel pipe after expanding diameter and hydraulic test;

15. Magnetic particle inspection at the tube end: This inspection is carried out to find defects at the tube end;

16. Anti-corrosion and coating: qualified steel pipes shall be anti-corrosion and coated according to user requirements.

Straight seam steel pipes have become an integral part of modern infrastructure, from oil and gas pipelines to water supply systems. Its durability, strength, and versatility make it the top material choice for various construction projects. But have you ever wondered how these pipes are manufactured? In this blog post, we'll be delving into the production technology of straight seam submerged arc welding steel pipe - from materials and equipment to quality inspection. So buckle up and let's explore the fascinating process behind one of the most reliable piping solutions available today!

Straight seam steel pipe expansion technology

Straight seam steel pipe expansion technology is an essential step in the manufacturing process. This method allows the pipes to achieve their desired diameter and thickness, making them more suitable for various applications.

The first step in straight seam steel pipe expansion involves cutting a strip of steel into a specific width and length. The edges are then prepared by milling or planing to ensure they are smooth and free from burrs or other imperfections that may affect the welding process.

After preparing the edges, the strip is fed through a series of rollers to form it into a round shape. This process compresses the metal inward while stretching it outward, resulting in an increase in diameter and wall thickness.

Once expanded, the pipe undergoes further processing such as trimming excess material off its ends and washing it clean of any debris before moving on to submerged arc welding manufacturing technology.

In summary, straight seam steel pipe expansion is crucial to ensure uniformity in size and strength throughout each section of piping. With this technology's precision engineering capabilities coupled with high-quality materials used during production stages come robustness that can withstand harsh environments without compromising quality performance over time.

Submerged arc welding steel pipe manufacturing technology

Submerged arc welding (SAW) is a popular method used in the production of straight seam steel pipes. This technique involves using an electric arc to melt the metal and then a layer of granular flux to protect it from impurities during the welding process. The SAW method ensures that high-quality, uniform welds are produced with minimal distortion.

In submerged arc welding steel pipe manufacturing technology, there are two variations: double-sided and single-sided. Double-sided submerged arc welding requires two electrodes while single-sided only needs one electrode. Both techniques have their advantages depending on the type of project being undertaken.

Materials and equipment required for SAW include: power sources, wire feeders, control systems for voltage and amperage regulation, welding guns or torches for feeding electrodes into weld areas and removing slag from completed welds.

Preparation for submerged arc welding includes cleaning surfaces to be welded free from rust or other contaminants such as oil or grease which can affect bonding quality between metals; properly aligning pieces before starting work so that they match up perfectly when finished; checking all electrical connections prior to beginning work ensuring proper grounding takes place at all times throughout this process.

The actual SAW process begins after preparation has been completed by positioning parts together tightly enough that no movement will occur during application of heat via electric current supplied through electrodes held near but not touching them - these must also remain clean themselves once placed into position!

Materials and Equipment

To produce high-quality straight seam submerged arc welding steel pipes, it is essential to have the right materials and equipment. Typically, these include a variety of raw materials such as low carbon steel plates or coils, filler metals, fluxes, and shielding gases.

The most commonly used material for manufacturing straight seam steel pipes is low carbon steel due to its excellent weldability and affordability. High tensile strength steels are also widely used in applications that require greater resistance to pressure and corrosion.

In terms of equipment, manufacturers typically use a range of machines such as plate shears, edge milling machines, pre-bending machines for forming the edges of the pipe before welding. Other key tools include automatic welding machines that utilize the latest technology like laser tracking systems for precision control during production.

Apart from this specialized equipment mentioned above; other basic requirements needed for producing superior quality welded tubes are overhead cranes for handling heavy loads and mobile cranes with adjustable booms for easy movement within the factory premises.

There is no doubt that selecting top-quality materials combined with modern manufacturing facilities can produce exceptional results when it comes to high-strength straight-seam submerged arc-welded steel pipes.

Preparation for welding

Preparation for welding is a crucial step in the production of straight seam steel pipes. It involves several processes that need to be followed meticulously to ensure quality welds and seamless pipe production.

Before any welding can take place, the materials must first be prepared. This includes cleaning and removing any rust or debris from the surface of the steel, as well as ensuring that both ends are square and aligned correctly.

Once cleaned, the material should be checked for alignment by using a straight edge or laser level. This process ensures that there will be no issues with distortion during welding.

The next step is preparing the equipment: selecting appropriate electrodes, fluxes and other consumables required for submerged arc welding operation. The welding machine settings such as voltage, amperage & wire speed also need to set up carefully based on specific requirements.

It's important to have proper ventilation when performing submerged arc welding because of fumes generated by this process; therefore work area should always have an effective ventilation system installed before starting any related job

Preparation is key to producing high-quality welded seams in straight seam steel pipes. Careful attention should always be given to each detail along with following safety guidelines throughout all stages of preparation until final delivery stage

Welding process

The welding process is a crucial step in the production of straight seam submerged arc welding steel pipes. It involves joining two metal pieces together to form one continuous piece, which is essential for creating an efficient pipeline system.

Before beginning the welding process, it's important to check that the materials and equipment are prepared correctly. This includes ensuring that the surface of each metal piece is clean and free from any contaminants such as oil or rust.

Once preparation is complete, the actual welding begins. The welder uses a machine to create high temperatures on either side of the joint area, causing both metals to melt and fuse together. A filler material may be used if necessary to ensure a strong bond between the two pieces.

During this process, it's crucial to maintain consistent heat levels and pressure on both sides of the joint area for optimal results. After completing all welds along the length of pipe, inspection must be conducted before moving forward with further steps.

Proper execution during this stage ensures that straight seam welded steel pipes can withstand high-pressure applications without risk of failure or leakage over time.

Heat treatment

Heat treatment is a critical step in the production of straight seam submerged arc welding steel pipes. This process involves heating and cooling the welded joints to improve their physical properties, such as strength, toughness, and ductility.

The heat treatment process typically involves two stages: preheating and post-weld heat treatment (PWHT). Preheating is done before welding to reduce thermal shock on the materials being joined. The PWHT stage is performed after welding to relieve residual stresses that may have developed during the manufacturing process.

The temperature and duration of heat treatment depend on factors such as pipe diameter, wall thickness, material grade, and intended application. To ensure consistency in quality control, strict guidelines are followed for each batch of pipes produced.

During heat treatment, it's essential to maintain controlled heating rates and uniform temperatures across all parts of the pipe being treated. Failure to do so could lead to non-uniform microstructures or even cracking.

Proper heat treatment plays a crucial role in ensuring that straight seam submerged arc welding steel pipes meet the required specifications for various applications while maintaining high levels of durability and integrity.

Quality Inspection

Once the welding process is complete, a series of quality inspections should be carried out to ensure that the straight seam submerged arc welding steel pipe meets all necessary standards. These inspections include checking the appearance and size of the weld, as well as conducting various non-destructive tests such as ultrasonic testing and X-ray inspection.

If any defects are found during these inspections, they must be addressed before the steel pipe can be considered ready for use. This ensures that customers receive high-quality products that meet their specifications and requirements.

Straight seam submerged arc welding steel pipe production technology requires careful preparation and attention to detail at every stage. From selecting materials and equipment to carrying out quality inspections, each step must be executed with precision in order to produce a reliable product. With proper training and expertise in this manufacturing technique, companies can provide their clients with durable and efficient piping solutions for a variety of applications.

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