What is seamless steel pipe

Seamless steel pipe is perforated by the whole round steel, the surface of the steel pipe without weld, called seamless steel pipe. According to the production method, seamless steel pipe can be divided into hot rolled seamless steel pipe, cold rolled seamless steel pipe, cold drawn seamless steel pipe, extruded seamless steel pipe, pipe jacking, etc. According to the shape of section, seamless steel pipe is divided into round and special-shaped, special-shaped pipe has square, oval, triangle, hexagonal, melon seed, star, winged pipe and a variety of complex shapes. The maximum diameter is 900mm and the minimum diameter is 4mm. According to different uses, there are thick wall seamless steel pipe and thin wall seamless steel pipe. Seamless steel pipe is mainly used as petroleum geology drilling pipe, petrochemical cracking pipe, boiler pipe, bearing pipe and automobile, tractor, aviation high-precision structural steel pipe.

Features of seamless steel pipe

1. Seamless steel pipe is actually hollow inside, has a certain cross section, no joints around the steel pipe, the shape of square, round and other common forms. Seamless steel pipe as the name implies the use of steel material through the perforation process made of wool pipe, and then through hot and cold rolling or cold dial process produced products. Because the steel pipe is hollow inside, it can transport some liquid. In addition, compared with the traditional solid steel, it has greater compressive strength and lighter volume. It is an ideal economic steel pipe. It is widely used in manufacturing and processing industries, such as oil drill pipe, car frame and scaffolding used in construction.
2. Seamless steel pipe can also be made into ring shaped parts, maximizing the use of materials, and simplifying the production process, effectively shortening the production cycle. At the same time, steel pipe also plays a large role in some weapon manufacturing, such as gun barrel need to use steel pipe to manufacture. Seamless steel pipe can be divided into circular and heterosexual products according to the different hollow cross section. In the case of the same circumference of the two products, the circular steel pipe will transport more liquid, and the internal force of the pipe will be uniform. However, the circular steel pipe is not as good as the special-shaped steel pipe in bending, so it can be used in different fields according to different performance characteristics of steel pipe.

Types of stainless steel pipe

The rolling method is divided into hot rolling, hot extrusion and cold drawing (rolling) stainless steel pipe.
According to the different microstructure of stainless steel, it can be divided into semi-ferritic semi-martensitic stainless steel pipe, martensitic stainless steel pipe, austenitic stainless steel pipe, austenite-ferritic iron stainless steel pipe and so on. Main business of Shaanxi Hualite Trading Co., LTD. Baosteel, Baotou steel and other national high quality seamless steel pipe, alloy pipe, etc. Uqi has a good reputation in the field of thick wall pipe, special pipe, high pressure boiler pipe and alloy pipe.

Stainless steel pipe specifications and appearance quality

A: According to gb14975-94 stainless Steel Seamless Steel Pipe, the steel pipe is usually 1.5 ~ 10m in length (variable feet), and the hot extruded steel pipe is equal to or greater than 1m. Cold-drawn (rolled) steel pipe wall thickness of 0.5 ~ 1.0mm, 1.0 ~ 7m; Wall thickness greater than 1.0mm, 1.5 ~ 8m.
B: hot rolled (hot extrusion) steel pipe diameter 54 ~ 480mm altogether 45 kinds; There are 36 kinds of wall thickness 4.5 ~ 45mm. 65 kinds of cold-drawn (rolled) steel pipes with diameters of 6 ~ 200mm; There are 39 kinds of wall thickness between 0.5 and 21mm.
C:There shall be no cracks, folds, cracks, crackles, lamination and scarring defects on the inner and outer surfaces of steel pipes. These defects shall be completely removed (except for pipes used for mechanical processing), and the wall thickness and outer diameter shall not exceed negative deviations after removal. Other minor surface defects that do not exceed allowable negative deviations may not be removed.
D:The allowable depth of the straight. Hot-rolled and hot-extruded steel pipes, with diameters less than or equal to 140mm, no more than 5% of the nominal wall thickness, and the maximum depth no more than 0.5mm; Cold-drawn (rolled) steel pipes shall not be greater than 4% of nominal wall thickness, and the maximum depth shall not be greater than 0.3mm.

Both ends of the steel pipe should be cut at right angles and burrs removed. Stainless steel seamless pipe manufacturing process: Hot rolling (extruded seamless steel pipe) : round pipe billet → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → pipe stripping → sizing (or reducing) → cooling → straightening → water pressure test (or defect detection) → marking → storage