Technology

The technology of production of hot-rolled pipes

Iron and steel shaped as round bars are used as the raw material in producing hot-rolled pipes.

When producing seamless hot-rolled pipes, the works uses three units for plugging tubes on a short Steifel-type mandrel, one unit for plugging tubes on a long mandrel in an Assel-type three-roller shaft, and one unit with a continuous mill for plugging tubes on a long movable mandrel.

Hot-rolled pipes are shipped to end users, as well as employed as stock for cold conversion (production of cold-formed pipes).

Mill "30-102", one of the most efficient and modern units in the world, which produces pipes with diameters of 32 mm to 108 mm and a wall thickness from 3 to 8 mm. Unit capacity is 715000 tons of pipe per year.

The technology of production of cold-formed pipes

Hot-rolled skelp (hot-rolled pipes of proprietary manufacture), subjected if necessary to mechanical boring and turning, is used as the raw material in producing cold-formed pipes.

For producing cold-formed pipes with diameters of 0.2 mm to 127 mm with a wall thickness of 0.05 mm to 12 mm from carbon, alloy and high-alloy steels and alloys, the works operates 76 cold rolling mills, 33 tube-drawing benches, and 41 mills for cold rolling tubes using castors, and mills for coil and mandrel drawing. Assembly lines also operate for coil drawing very thick-walled tubes for diesel engine fuel lines; finned pipes for gas heat boilers and seamless section pipes of varying shape are also produced.

Rolling is done in warm or cold mode with the use of emulsion or oil.

The high quality of pipes is ensured through the use of protective atmospheres in the finishing process, as well as by polishing and electro-polishing of the inner and outer surfaces.

The technology of production of electro-welded pipes

Strip (coiled sheet steel) from iron and steel works is the raw material used in producing electro-welded pipes.

The works has nine electro-welding mills for producing straight-seamed electro-welded pipes with a diameter of 0.4 mm to 114.3 mm. A high-frequency welding method is used for producing pipes from carbon steels, while an arc welding method in a medium of inert gases is used for making pipes from high-alloy steels. These technologies, coupled with physical control and hydraulic test methods, ensure pipe reliability in engineering and in structural construction.

Internal flash removal and the high purity of the inner pipe surface provide for a high-quality product. Welded pipes may additionally be subjected to mandrel and sink drawing and rolling on forming mills. Thermal treatment in a furnace with a protective atmosphere ensures a bright pipe surface.