The production of steel pipe:
Steel pipe is an important part of the pipe industry, with a wide range of applications. It is mainly used for transporting oil and gas, engineering projects and urban pipe network construction. There are many ways to produce steel pipes, such as ERW steel pipe, seamless steel pipe, and so on. The following is a description of the production method of ERW steel pipe.
The production of ERW steel pipes mainly consists of five main processes―cold chain raw material inspection and handling, steel pipe forming, welding, heat treatment of welded joints and non-destructive testing.
First, cold chain raw material inspection and processing. Before use, the steel plate or coil shall be inspected to see whether the surface of the sheet and coil is clean, without sand holes, rust, corrosion and other defects which will affect the quality of the steel pipe. The inspection method is usually uncoiling, cutting into sheets, flat inspection and end face inspection. After inspection, the sheet material must be leveled and cut.
Second, the forming process. The steel sheet is formed into a steel pipe by a forming machine. The forming machine is composed of a roll stand and a forming and sizing unit. The forming process includes pre-bending, forming, welding at both ends, reduction and sizing. The forming process uses a spiral steel pipe forming method and a straight steel pipe forming method.
Third, welding. After forming, the two ends of the pipe are welded by a high-frequency welding machine. The welding current and parameters of the welding machine need to be adjusted according to the type and wall thickness of the steel pipe.
Fourth, heat treatment of welded joints. The steel pipe weld has a large residual stress and deformation, so the welded joint must be heated to balance the stress, reduce the deformation and improve the quality of the welded joint. The heat treatment temperature and duration of the welded joint need to be adjusted according to the type of steel pipe and the wall thickness.
Fifth, non-destructive testing. After welding and heat treatment, the quality of the welded joint needs to be tested to ensure that the weld has no defects. Commonly used non-destructive testing methods include X-ray radiography, magnetic particle testing and ultrasonic testing.
Finally, the finished steel pipe is sent to the finished product warehouse. After these five processes are completed, the steel pipe can enter the finished product warehouse and be used in various pipelines.
Steel pipes play an important role in our daily life. All kinds of steel pipes are produced in different ways. The production method of ERW steel pipe described above is an example. By understanding the production method of steel pipes, we can truly understand the production process of steel pipes and the importance of steel pipes in our daily life.
