Forming large size seamless pipe fittings

Large size seamless pipe fittings forming technology are: hot spinning method, hot extrusion, hot piercing rolling method, thermal expansion push the system path method. As follows:
1, hot spinning method
It is the flat blank or pre-formed blank is fixed to the rotating mandrel, spin the wheel blanks pressure while rotating wheel for axial feed, through one or more processing, to obtain a variety of thin-walled hollow rotary system the process of goods. Its advantages are high precision, good mechanical properties, wide range of sizes. Tools mold is simple, easy to replace, lower production costs than other methods. The main disadvantage is the production of long working hours, low output, the processing of the tube by the device length limit, the size is short.

2, the hot extrusion method
Required before extrusion billets were machined pretreatment, when squeezing the tube diameter less than 100mm, the equipment investment is small, less material waste, technology is more mature. But once the tube diameter size increases, the use of hot extrusion method requires large tonnage and high-power devices, the corresponding control system should be upgraded.

3, hot piercing rolling method
Hot piercing rolling the longitudinal extension and cross rolling mill extension based. Rolling and rolling extending mainly limited MPM rolling, less rack MPM tube rolling, three-roll MPM tube floating mandrel mill rolling and rolling. These methods produce high efficiency, low metal consumption, good product quality, advanced control system is widely used. Oblique Rolling rolling method with less investment, short process, suitable for low-volume, multi-species, multi-standard and high-precision production of seamless pipes and the same has been widely used.

4, the thermal expansion push the system path method
Push the system expanding device is simple, low cost, easy maintenance, economical and durable, flexible product specifications transform, if necessary, prepare a large-diameter elbow and other similar products, you only need to add some accessories to. Suitable for the production of thin-walled seamless tube diameter Heavy timber, it can not exceed the production capacity of the thick-walled steel pipe equipment.