Manufacturing process of stainless steel tubes

Pipe parameters

The automatic mills are doing pipe with outer Ø 7 42.6 cm and a length of 6−16 meters. If the production line included a pressure-reducing mill, it is possible to manufacture pipes with external Ø of 4 cm. The source material is rolled round billet. Performance installations with automatic mill 400 about 60 t/h.

The stages of

Billet before rolling is centered and heated to 1200 °C in the furnace. Rolling tubes 12x18н10т goes through the following stages: first, the workpiece is sewn in the hollow sleeve, followed by the rolling of the sleeve in the tube, rolling, polishing the surface (external and internal), calibration and correction.

Firmware

The workpiece is converted into the sleeve in the piercing mill with the barrel, disk or mushroom-shaped rolls. Although the design of the mills are different, the principle of their action alone. Getting shells in piercing mill is by using a pair of rolls — their axes are at an angle of 5−20°to the axis of the workpiece. The rolls rotate in the same direction. Under the action of the rolls, the workpiece begins to rotate in the opposite direction moves progressively forward. Between two rolls set line in order to direct the movement of the workpiece in the mill and prevent its slipping from the rolls by the firmware. Also between the rollers is a tapered mandrel held by the rod, the other end of which is secured in the supporting swivel bearing. From the rolls between the input and output cone has a cylindrical portion. When the workpiece arrives in the piercing mill, it put pressure on the rolls themselves and of the friction force with the contact surface of the workpiece and the rolls. This creates a stress state in the cross section of the workpiece, favorable for the occurrence of cavities. Therefore, the mandrel can be easily incorporated in an axial portion of the preform, forming the wall of the sleeve, which is further rolled in the output cone of the rolls. After flashing sleeve shall be sent to automatically become available for further processing.

Automatic pipe rolling mill

Here decreasing the thickness of the wall and lengthened the sleeve. The camp 2 of the frame, which are rolls which rotate by the motor through gear crate, installed on the opposite side. With the help of the rolls is formed round caliber. Its size depends on the outer diameter of the pipe. The mandrel is mounted on the end of a long rod in the caliber. The opposite end of the rod is fixed in traverse lock the rear table of the mill. Rotating the rolls grip the tube, which is crimped between them and the stationary mandrel. In accordance with the caliber decreases and the diameter of the stainless pipe. The annular gap between the mandrel and a surface gauge, determine the thickness of the tube wall. Stainless pipe is moved on the front edge of the mill rollers reverse flow equipped with round gauges. The rollers rotate in the opposite direction relative to the rotation of the rolls. At the lift levers, which are pneumatic cylinder, fixed bottom roller. In this case, the work rolls apart. Tube being turned over, turning 90° around its axis on the input side of the mill and between the rolls set a new bar, and then start the second pass. Often the rolling of tubes is carried out in 2−3 passes.

Raskaty mill

After rolling the resulting tube is passed into raskaty mill where rolled out bumps on its outer and inner surfaces. Here the rolls are arranged in a vertical plane at an angle of 6 to 6.5° relative to each other. In the horizontal plane of the axis of the rolls remain parallel. The rolls rotate in the same direction, so when the trumpet enters the camp, she gains both translational and rotational motion. The long rod between the two rollers set the bar. Pinch or stretch rolls determines the amount of unrolling. Further, from the reeling mill pipe or act immediately in the sizing mill or first heated and then rolled in the reducing mill.

Sizing mill

It is needed in order to get the exact outer diameter of the pipe. This camp usually consists of 5 or 7 working rolling mill stands. Each of these stands there are 2−3 roll with oval or round gauges. In the calibration mill rolls rotate in opposite directions. The rolls grip the tube, and it is crimped in groove diameter, while acquiring a more accurate size.

Reduction mills

They are required to reduce the pipe diameter, consist of 10, 12, 18, 24 crates. Each crate in the old reduction mills includes 2 roll. Calibre, through which passes a pipe, in new mills formed with the help of 3−4 rolls. This allows to obtain when rolling more uniform compression of the tubes. In the reducing mill is supplied pre-heated tube (up to 1050 — 1100°C). Passing through all the rollers, it elongates and, accordingly, is reduced in diameter. Absolutely all the latest reduction mills during the rolling process, working with tension of the pipe, whereby pipes with wall thickness up to 2 millimeters. In functioning without tension reducing mill, the wall thickness increases.

Cooling table

After the calibration or the reducing mill, the pipe going to the cooling table, on which there is a series of moving chains. These chains are ready, the pipe rolls, it gradually cools down. When the temperature of the product becomes sufficiently low, and there is no danger of bending or buckling, the pipe give the cold edit. She is on the right kosovelova mills.

To buy, price

In stock, LLC «" always available high-quality metal. We offer stainless steel tubes at the best prices. It is formed taking into account technological features of production and does not include additional costs. All products are certified. The timing of orders is minimal. Wholesale buyers get a preferential discount.