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Several Production Methods For Seamless Tubes

Date:2019-01-28    keywords:seamless steel tube
The seamless steel tube is a long strip of steel with a hollow section and no seams around it. Its characteristics are as follows:
First, the thicker the wall thickness of the product, the more economical and practical it is, the thinner the wall thickness, the greater the processing cost of the seamless pipe factory; secondly, the process of the product determines its limitations. Performance, general seamless steel pipe with low precision: uneven wall thickness, low brightness inside and outside the tube, high fixed-length cost, and pitting and black spots on the inside and outside of the table are not easy to remove; third, its detection and shaping must be processed offline. Therefore, it embodies its superiority in high-pressure, high-strength, mechanical structural materials.

Seamless pipe process: tube blank - inspection - stripping - inspection - heating - perforation - pickling - grinding - lubrication and air drying - welding head - cold drawing - solution treatment - Pickling - pickling passivation - inspection - cold rolling - oil removal - cutting head - air drying - internal polishing - external polishing - inspection - identification - finished packaging

The manufacturing process includes hot rolling, cold drawing, and heat expansion. According to different production methods of seamless pipe factory, it can be divided into hot rolled pipe, cold rolled pipe, cold drawn pipe and extruded pipe.

1.1. Hot-rolled seamless pipes are generally produced on automatic rolling mills. The solid tube blank is inspected and the surface defects are removed, cut into the required length, centered on the end face of the perforated end of the tube blank, then sent to a heating furnace for heating and perforated on the punching machine. At the same time, the perforation is continuously rotated and advanced. Under the action of the roll and the head, a cavity is gradually formed inside the tube blank, which is called a capillary tube. Then send it to the automatic pipe rolling machine to continue rolling. Finally, the whole machine is uniform in wall thickness, and the sizing machine is sizing to meet the specification. The production of hot-rolled seamless steel tubes by continuous rolling mills is a more advanced method.

1.2. If you want to obtain seamless pipes of smaller size and better quality, the seamless pipe factory must adopt cold rolling, cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill in which the steel pipe is rolled in an annular hole type composed of a variable-section circular hole groove and a stationary tapered head. Cold drawing is usually carried out on a single-chain or double-chain cold drawing machine of 0.5 to 100T.

1.3. Extrusion method The tube blank to be heated is placed in a closed extrusion cylinder, and the perforated rod moves together with the extrusion rod to extrude the extrusion from the smaller mold hole. This method can produce steel pipes with smaller diameters.

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