1, Hot extrusion method: the need for pre-extrusion processing of blank pre-treatment, when the extrusion diameter of 100mm below the pipe, the equipment into small, less waste of materials, technology is more mature. However, once the pipe diameter size increases, the use of hot extrusion method requires large tonnage and high-power equipment, the corresponding control system should be upgraded.
2, Hot piercing rolling method: hot piercing rolling rolling and rolling to extend the main extension. Rolling and rolling of continuous mandrel bar, continuous rolling of mandrel bar, rolling of mandrel bar, rolling of mandrel bar and rolling of mandrel mill. These methods have high production efficiency, low metal consumption, good product quality, advanced control system and wide application. The skew rolling method has the advantages of low investment, short process, suitable for small batch, multi-variety, multi-specification and high-precision middle and thick-walled seamless pipe production and also has been widely used.
3, Hot push system expansion method: push system expansion equipment is simple, low cost, easy maintenance, economic and durable, flexible product specifications change, such as the need to prepare large diameter elbow and similar products, only need to add some accessories. Suitable for the production of thin-walled thick-walled steel pipe, can also produce equipment does not exceed the capacity of thick-walled tube.
