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

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. Manufacturers produce tubular products of fixed or random length, length parameters can be agreed with the customer. GOST 8733-74 establishes supply groups with standardized criteria: · B – mechanical properties; B - chemical composition; D - chemical composition and mechanical characteristics after heat treatment; D - hydraulic pressure; E - mechanical properties after special heat treatment. Cold-formed products apply an additional classification according to GOST 8734-75: Particularly thin-walled - up to 0.5 mm; Thin-walled - up to 1.5 mm; Thick-walled - the ratio of the outer diameter to the wall thickness is not more than 6; Extra thick-walled - the ratio of the outer diameter to the wall thickness is from 6 to 12.5. Products can be classified according to the grades of steel from which they are made. The cold process allows the production of products of any shape and high precision, including bicycle frames, stainless steel railings and guardrails. Production of seamless pipes With the hot method, the cylindrical billet is heated in a furnace, then, in a hot form, it enters the piercing mill, where it is pierced and passes through the crimping rolls located at an angle. This is how a thick-walled sleeve is obtained, equal in diameter to the original blank, but 2.5-4 times longer. Rolling is carried out on an automatic, continuous or three-roll mill. The choice of equipment determines the characteristics of the finished product. At the final stage, the still hot pipe enters the sizing mill, cools down and undergoes stabilizing annealing to relieve residual stresses and strengthen the alloy structure. Cold deformation involves many operations. In production, pre-pierced sleeves are used, cleaned of scale, dried in a special chamber and coated with grease. Production by rolling or drawing is possible. Unheated steel changes shape slowly. The process is divided into several stages, after each heat treatment and etching are performed to remove oxides. The protective anoxic environment allows to reduce or eliminate the treatment with acidic compounds. The number of cycles is from 5 to 15. Then calibration, grinding inside and outside the pipe is performed. The surface of stainless steels can be polished to a mirror state. Hot-formed products have an outer diameter of 20-550 mm. with a wall thickness of 2.5-70 mm. Cold-formed - section diameter: 5-250 mm., wall: 0.3-24 mm. Seamless steel pipes, depending on the production method, have different purposes and properties. For some areas, it is possible to apply the standards of technical specifications, for example, in the manufacture of furniture or fences, hydraulic pressure parameters are not important. Seamless steel pipes are the most durable among other tubular products. The solid wall, along with the nature of the metal, provides pipelines with exceptional capabilities - they operate in harsh conditions of high temperatures and pressures. Seamless steel pipes are expensive products, for the production of which special equipment and technologies are used. Seamless pipes are produced from steel - a high-strength alloy of iron and carbon, which has hardness and resistance to external influences. The absence of a seam and thick walls put this pipe material out of the competition. The technical characteristics of seamless pipe products depend on the steel grade and the method of their production - hot or cold rolling. The release of products is regulated by specially developed GOST standards (state standard). At the exit from the rolling mill, a product must be obtained that strictly corresponds to the specified parameters.