The invention relates to the field of seamless
steel tube processing, and discloses a seamless
steel tube production process and a seamless
steel tube production line, a size changing process is added between a traditional heating process and a traditional
punching process, and a square blank or a large-
diameter circular blank (a first blank) is changed into a small-
diameter circular blank (a second blank). The size changing procedure can be achieved through independent or combined rolling, push rolling and
skew rolling processes, for example, push rolling is adopted for changing square billets into round billets, and a two-roller or three-roller
skew rolling round billet
machine is adopted for reducing the
diameter. The first blanks in the
heating furnace are arranged in double rows, meanwhile, the product outline is adjusted according to the capacity of a unit, and the front portion, the rear portion and the middle portion are subjected to optimized production, wherein double-row
material distribution is achieved, the finished products are as long as 12 m, and
cutting head loss is reduced. The matched
production line is provided with size
changing equipment (such as a section mill, a push mill and a
skew mill combination) between a
heating furnace and a perforating
machine, square billets or round billets can be flexibly processed, the
material distribution efficiency, the finished product length and the cost are balanced through the size changing technology, and the economical efficiency and flexibility of seamless steel
pipe production are improved.