.Φ17mm～ Φ426mm pipe

Continuous seamless mill

1.Pipe mill unit features:
     The complete set production line of the rolling mill unit is a vertical rolling mill unit.The continuous three-roll hydraulic pressure roll stand is used together with the mandrel circulation limit system to produce the precision steel tube efficiently and with high quality,suitable for large-scale and high-precision of the pipe production,is the highest lever of today's rolling mill.

2.introduction of pipe rolling process:
    The production line consists of piercing machine,continuous pipe rolling machine,tension reducing machine.The round billet is inserted into the mandrel and inserted into the mandrel,followed by a two-roll mill having a 90 ^o arrangement of 7 to 9 roll axes.After pulling the mandrel rolling,reheating after tension reduction,can be rolled up to up to 165m of steel.140mm continuous pipe mill with an annual output of 40 to 600000 tons,automatic rolling unit 2 to 4 times.The characteristics of this unit is suitable for the production of steel pipe diameter 168mm,equipment investment,installed capacity,mandrel up to 30m,processing and manufacturing complex.In the late 1970s,MPM(Mandrel Continuous Tube Rolling Mill)was introduced,which forced the mandrel to move less than the tube speed during rolling to improve the metal flow conditions and to use the short mandrel to roll the long and large diameter tubes.
     Common series have an outer diameter of 100mm,140mm,250mm and 400mm four kinds of production diameter 17~426mm steel.The unit is characterized by the main deformation on the piercing machine,the more flexible specifications,the wider range of production varieties.Due to the continuous tube rolling technology,no longer the construction of the unit below 140mm.

3.the history of technology development:
    Seamless steel pipe production has nearly 100 years of history.German Manisman Brothers first invented in 1885 two roller cross-piercing punching machine,in 1891 invented the cycle of pipe rolling machine ,in 1903 the Swiss Shi Feifel(RCStiefel) invented the automatic pipe mill (also known as head-type rolling pipe machine),and later appeared a continuous tube rolling mill and pipe jacking machine and other extension machines,began to form a modern seamless steel pipe industry.
    Nineteen thirties due to the use of three-roll pipe mill,extrusion machine,periodic cold rolling machine,improved the quality of steel varieties.
    In the 1960s,due to the improvement of the continuous tube rolling mill,the emergence of the three-roll perforating machine,especially the application of tension reducing machine and continuous casing slab,improved the production efficiency and enhanced the competition ability between the seamless pipe and the welded pipe.In the 1970s,seamless pipes and welded pipes are keeping pace.The world's steel pipe production is increasing at an annual rate of over 5%.
    After 1953,China attached importance to the development of seamless steel pipe industry and has initially formed a production system for rolling all kinds of large,medium and small pipes.Seamless pipe is also generally used billet oblique rolling perforation,rolling mill machine,coil drawing process.