The forming technology of seamless steel pipe

　　Seamless steel pipe forming techniques mainly include: hot spinning method, heat extrusion method, hot piercing rolling method, including preparation of expanding method. The details are as follows:

　　1, Hot spinning method

　　It is the flat blank or pre molded blank is fixed to the rotating core rod, the pressure with the rotary wheel blank, rotation and axial feeding, after one or more processing, get the process of thin-walled hollow rotary body products. Its advantages are high precision products, good mechanical properties, size range.

　　2, Hot extrusion method

　　The need for billet machining pretreatment before extrusion, the extruded API 5L GR. B Carbon Steel Seamless Steel Pipe diameter below 100mm, low equipment investment, less waste of materials, technology is more mature. But once the pipe diameter size, by using the method of hot pressing need of large tonnage and large power equipment, the corresponding control system to upgrade.

　　3, Hot piercing rolling method

　　Hot piercing rolling in longitudinal rolling extension and cross rolling elongation. good product quality, advanced control system, widely used. Cross rolling elongation rolling method with less investment, short process, suitable for small batch, multi varieties, multi specifications and high precision in the thick wall seamless steel pipe production and also obtained the widespread application.

　　4, Push the process of expanding method

　　Pushing expanding diameter has the advantages of simple equipment, low cost, convenient repair, economic and durable, the product specifications flexible transformation.