Lvov pipe steel seamless cold-smoked, hot-smoked steel st20, st45 6-630 mm (Metallobaza) delivery, cutting

The main purpose of a seamless pipe is high-pressure pipelines or the transport of hazardous substances in industrial facilities. When a leak or rupture could threaten the safety of life or the environment. In domestic engineering networks, there are no loads that a straight-seam pipe could not withstand, however, the absence of a seam increases the service life, durability and reliability, for example, of gas equipment in a private house. Seamless pipes can be bent without loss of quality, so they are used for the manufacture of coils, spirals and bent bends. Applications of seamless steel pipes: High pressure gas and oil pipelines; Chemical pipelines for transportation of solutions of acids, alkalis, toxic gases; Coils and spirals of industrial heat exchangers, water heaters; Systems with closed circuits; Extraction of gases and combustion products from blast furnaces; Details of piston mechanisms; Pipeline accessories; Foundation piles for power transmission lines and other metal structures. The main advantage of a seamless body is tightness, resistance to tearing and corrosion, since all adverse factors associated with a welded joint are excluded: residual stresses, microheterogeneity, sagging, loss of elasticity. Classification of seamless pipes Products are made of carbon and alloy steels, especially stainless steels. Manufacturers use two methods: Cold-rolled GOST 8733-74; Hot-rolled GOST 32528-2013 (GOST 8734-75 is valid with clarifications). Hot-rolled pipes are obtained from hot cylindrical billets; heating modes from 900 to 1270 Co are used for different steels. During hot rolling, the structure of the metal retains its elasticity, compacts, but it is impossible to obtain a thin-walled material. The cold method includes several stabilizing annealings, during which the metal grain is ground, and residual stresses are removed, the structure becomes homogeneous and strong. The deformation is carried out in a cooled state, but the metal in the rolling machine is strongly heated due to friction. This method allows the production of high-precision products with thin walls. Pressing during hot deformation changes the structure of the metal, it becomes inhomogeneous. For some steel grades, stabilizing annealing or hardening is provided. Thick walls can withstand any pressure, both external and internal, are not susceptible to movement and soil mass. Hot rolled pipes are coated with scale, but if increased corrosion resistance is required, they are cleaned and zinc, chrome or polymer coating is applied. Seamless hot-rolled pipes are used in the construction of engineering networks, oil and gas pipelines, but they cannot be used to transport poisonous and explosive substances with a high hazard class, to supply water vapor. The strength of products is valued in construction. The advantage of cold rolled pipes is light weight, increased strength at the molecular level, polished surface reduces corrosion. For additional protection, they are treated with galvanic methods, powder paints, galvanizing, but stainless alloys are more often used. Cold-formed products have many purposes and sizes: rolling from some steel grades is used in marine shipbuilding; chemical and food industry; energy; instrument making; capillary tubes are used in dosing equipment, electronics, aviation. Seamless pipes are able to withstand a standard pressure of several hundred atmospheres, and work for a long time in networks with pressure drops. The hermetic construction is protected from the destruction typical of a welded joint, and is absolutely resistant to air pollution. The production of pipes using seamless technology is much more expensive than electric-welded pipes, so their use is due to economic feasibility. The selection is carried out on the basis of the normative pressure of the transported substance, the mechanical characteristics of structures or parts.