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

Seamless pipe Seamless steel pipes are used in conditions requiring reliability and increased strength characteristics: in industrial and municipal pipeline systems with high pressure and temperature, for transporting liquid and gaseous media, as well as in construction as structural elements. Seamless steel pipes differ in the production method: hot-worked; cold-formed. The initial stages of manufacturing hot-formed and cold-formed steel pipes are the same (obtaining a sleeve from a billet by extrusion or on a piercing mill). Then, blanks for cold-formed pipes are cooled before further processing (unlike hot-formed ones), and subsequent additional technological operations allow you to adjust individual parameters: increase heat resistance, mechanical strength, and surface treatment accuracy class. Hot-formed seamless steel pipes for general purposes from carbon and alloy steels Nominal dimensions, weight of one meter and accuracy class for maximum deviations for hot-formed steel pipes from carbon and alloy steels are established by the assortment GOCT 8732-78. The technical conditions of production are regulated by GOCT 8731-74, the requirements for marking, acceptance and logistics are determined by GOCT 10692-80. Specifications according to GOCT 8731-74 Hot-formed pipes, depending on the performance requirements, are produced in five groups: for pipes of group A, made of carbon steels according to GOCT-380, mechanical characteristics are normalized; for pipes of group B from steels according to GOCT 380, 1050, 4543, 19281, the chemical composition is regulated; for pipes of group C (steel according to the same GOCT as for class B), the chemical composition and mechanical characteristics are regulated; for group G pipes made of steels according to GOCT 1050, 4543, 19281, the chemical composition is regulated and the control of mechanical characteristics is established; group D - the value of the test hydraulic pressure is normalized, mechanical properties and chemical composition are not regulated. Assortment, accuracy class and weight of hot-formed seamless pipes according to GOCT 8732-78 The GOCT 8732-78 range sets the following dimensional limits: minimum outer diameter 20 mm, minimum wall thickness 1.08 mm; maximum outer diameter 550 mm, maximum wall thickness 75 mm. The assortment and classification of seamless steel pipes are so extensive that it is easy to get confused in them. At the same time, in order to choose the right rolled products for specific production tasks, it is necessary to understand the basics: to know production technologies, the purpose of products and limitations in use. Otherwise, the budget may be spent inefficiently. Moreover, a seamless pipe is more expensive than analogues with seams due to its higher strength. We will talk about this and much more in the article. Technologies for the production of seamless pipes Seamless pipes are produced in two ways - using hot rolling and cold rolling. Both technologies are complex and costly. This is one of the reasons why seamless steel pipes are quite expensive. The product does not immediately enter the rolling mill. First you need to create a blank. For cold and hot rolling, they are made in the same way. To do this, use the following methods: Forging. pressing. Drawing. rolling. Further technologies differ. Hot rolling consists of the following steps: Preparations. The billet is heated to a temperature of 1180–1200 °C. Sleeve creation. Using a special mushroom drill, a large hole is made in the axial part of the workpiece. Now the product becomes more like a pipe. After the sleeve is sent to the rolling mill. Actually rolling. Here, the inner and outer walls of the product are clamped between two rotating rollers. This is how the diameter and wall thickness are adjusted. To adjust these parameters to the desired values, a special limiter is installed on the rolling mill. To fit the seamless pipe to the range, this cycle is repeated several times until a perfect result is achieved. Cold-rolled steel is characterized by a particularly smooth surface. In addition, the deformation of the workpiece here occurs without the use of high temperatures. Therefore, the technology consists of the following steps: Processing. For cold rolling workpieces are selected with great care. Then they are fired, pickled with acid. Next, you need to remove traces of these processes from the surface. To do this, the workpiece is treated with alkali. And only then does it undergo phosphating or copper plating. This is necessary to increase strength. Section formation. The pipe walls are clamped between two rotating rollers. This adjusts the wall thickness and diameter. The latter is changed by changing the angle of the rollers. Compressions. For him, the direction of movement of the pipe and rolls changes. So the achievements are fixed