Stainless steel seamless tube is a long steel with hollow cross section and no seams around. The thicker the wall thickness of the product, the more economical and practical it is, and the thinner the wall thickness, the higher the processing cost.
The process of the product determines its limited performance, the general seamless steel pipe precision is low: uneven wall thickness, low brightness of the tube appearance, high cost of sizing, and the internal and external appearance of the pockmarks, black spots are not easy to remove; its detection and shaping must be processed offline. Therefore, it reflects its superiority in high pressure, high strength, mechanical structure material.
Manufacturing method
According to different production methods can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, extruded tubes, etc.
1.1, hot-rolled stainless steel seamless pipe is generally produced on automatic tube rolling units. Solid billets are inspected and cleared of surface defects, cut to the required length, centered on the perforated end of the billet, then sent to the heating furnace for heating and perforated on the perforating machine. In the perforation while continuously rotating and advancing, under the action of the rollers and the top, the internal cavity of the billet gradually formed, called the hairpin. Then sent to the automatic rolling mill to continue rolling. After filtering, the wall thickness is evenly adjusted by an equalizer, and the diameter is fixed by a sizing machine to meet the specifications. The use of continuous rolling mill to produce hot rolled seamless steel pipe is a more advanced method.
1.2, if you want to get smaller size and better quality seamless pipe, you must use the cold rolling, cold drawing or both combined methods. Cold rolling is usually carried out in a two-roller mill, steel pipe in a circular hole pattern consisting of a circular groove with a variable section and an immobile conical head. Cold drawing is usually carried out on a single-chain or double-chain cold drawing machine of 0.5 to 100T.
1.3, the extrusion method is about heated billet placed in a closed extrusion cylinder, perforated bar and extrusion rod together with the movement of the extrusion, so that the extruded parts from the smaller die hole. This method can produce smaller diameter steel pipe.
This type of steel pipe can be divided into stainless steel seamless steel pipe and stainless steel welded steel pipe (seamed pipe) two categories, according to the different manufacturing processes can be For: hot-rolled, extruded, cold-drawn and cold-rolled these basic types, according to the shape of the section can be divided into round and shaped tube, widely used is round steel pipe, but there are some square, rectangular, semi-circular, hexagonal, equilateral triangle, octagonal and other shaped stainless steel pipe.
For steel tubes subjected to fluid pressure are subjected to hydraulic pressure test to test its pressure resistance and quality, under the specified pressure does not occur leakage, wetting or expansion for qualified, some steel tubes also according to the standard or demand side requirements for rolled edge test, flaring test, flattening test.
Seamless stainless steel pipe, also known as seamless stainless steel pipe, is made from ingots or solid billets that are perforated to make a blank tube, and then hot rolled, cold rolled or cold dialed.
