In practical applications, the straight shape of smls steel pipes is not always applicable. Because their standard length is usually long, it is difficult to meet the needs in specific scenarios, so bending processing is particularly important. Permanent Steel Manufacturing Co.,Ltd carefully summarizes the relevant information of seamless steel pipe bending:
Why should smls steel pipe be bent?
1. Change the direction of the pipeline: In the pipeline system, it is often necessary to change the direction of the pipeline to adapt to different layout forms and connection requirements. At this time, elbows are needed.
2. Reduce the use of pipe fittings: Using elbows can reduce the use of pipe fittings (such as elbows and tees), thereby reducing connection points, reducing the risk of leakage, and improving the reliability of the pipeline system.
3. Meet special design requirements: Some special equipment or structures require the use of elbows with specific shapes.
Methods of bending smls steel pipes
Hot bending method: The hot bending method is to first heat the seamless steel pipe to a certain temperature to enhance its plasticity and facilitate bending. The heating equipment can be a flame heating device or a resistance heating device. After the steel pipe reaches the appropriate temperature, the pipe bender is used to apply external force for bending. Accurate control of the heating temperature is crucial. If the temperature is too high, the grain of the steel pipe will grow, reducing the mechanical properties and corrosion resistance; if the temperature is too low, it will be difficult to bend. After bending, the cooling process also needs to be controlled. Excessive cooling can easily refine the grain of the steel pipe, increase brittleness, and cause cracks and deformation.
Cold bending method: The cold bending method does not require heating. With the help of special cold bending equipment or tools, such as pipe bending machines, rollers, etc., the seamless steel pipe is bent at room temperature. This method is suitable for small-diameter, thin-walled seamless steel pipes, and can avoid problems such as oxidation and deformation caused by hot bending. However, during cold bending, the steel pipe is subjected to greater stress, so it is necessary to pay attention to selecting appropriate tools and controlling the bending force to prevent defects such as cracks and wrinkles on the steel pipe.
Factors affecting the bending quality of smls steel pipes
1. Steel pipe material: Steel pipes of different materials have different plasticity and toughness, and different bending properties. Generally speaking, steel pipes with good plasticity and toughness are easier to bend and less likely to crack.
2. Steel pipe wall thickness: The thicker the wall thickness of the steel pipe, the more difficult it is to bend, requiring greater bending force, and it is more likely to deform.
3. Bending radius: The smaller the bending radius, the more difficult it is to bend, and it is more likely to deform and wrinkle.
4. Bending temperature (hot bending): Heating temperature that is too high or too low will affect the bending quality.
5. Bending equipment and molds: The accuracy and state of the bending equipment and molds directly affect the bending quality.
6. Lubrication: Using a suitable lubricant during the bending process can reduce friction, reduce bending force, and improve bending quality.
Main applications of smls steel pipe bending
1. Pipeline transportation: In the transportation process of energy such as oil and natural gas, the seamless steel pipe can be bent to achieve the turning connection of the pipeline, ensuring the smooth and safe transportation of the fluid. For example, in the West-East Gas Transmission Project, a large number of curved seamless steel pipes have built a huge transportation network, ensuring the long-distance and efficient transportation of natural gas.
2. Mechanical Manufacturing: In automobile manufacturing, the drive shaft needs to be bent into shape using seamless steel tubes to accurately transmit power and ensure the normal driving of the car. Bicycle frames are also mostly made of bent seamless steel tubes, which not only ensures strength but also reduces the weight of the vehicle body and improves the riding experience.
3. Construction field: When building steel scaffolding, the bent seamless steel pipe can be flexibly combined according to the building structure and construction requirements to provide a safe working platform for construction workers; in building structural parts, bent seamless steel pipes are used to construct complex shapes and structures to enhance the stability and aesthetics of the building. For example, the unique shapes of some large venues and art buildings are inseparable from the bending processing of seamless steel pipes.
