Seamless steel pipe is a steel pipe which is perforated by a whole round steel and has no weld on its surface, which is called seamless steel pipe. According to the production method, seamless steel pipes can be divided into hot rolled seamless steel pipes, cold rolled seamless steel pipes, cold drawn seamless steel pipes, extruded seamless steel pipes and pipe jacking. According to the cross-sectional shape, seamless steel pipes are divided into round and special-shaped pipes, and special-shaped pipes have many complex shapes such as square, oval, triangle, hexagon, melon seeds, star and finned pipes. Today, we introduce the most important classification of seamless steel pipes according to their uses.
Classification of seamless steel pipes:
1. seamless steel pipes for structures (GB/T8162-2008) are seamless steel pipes for general structures and mechanical structures.
2. Seamless steel pipes for fluid transportation (GB/T8163-2008) are general seamless steel pipes for transporting fluids such as water, oil and gas.
3. Seamless steel pipes for low and medium pressure boilers (GB3087-2008) are high-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel pipes for manufacturing superheated steam pipes, boiling water pipes and superheated steam pipes for locomotive boilers of various structures.
4. Seamless steel pipe for high-pressure boiler (GB5310-2008) is a seamless steel pipe made of high-quality carbon steel, alloy steel and stainless heat-resistant steel for the heating surface of water-tube boiler with high pressure and above.
5. High-pressure seamless steel pipe for chemical fertilizer equipment (GB6479-2000) is a high-quality carbon structural steel and alloy steel seamless steel pipe suitable for chemical equipment and pipelines with working temperature of -40~400℃ and working pressure of 10~30Ma.
6. Seamless steel pipes for petroleum cracking (GB9948-2006) are seamless steel pipes for furnace tubes, heat exchangers and pipelines in petroleum refineries.
7. Steel pipes for geological drilling (YB235-70) are used by geological departments for core drilling, which can be divided into drill pipes, drill collars, core pipes, casings and settling pipes according to their uses.
8. Seamless steel pipes for diamond core drilling (GB3423-82) are seamless steel pipes for drill pipes, core rods and casings for diamond core drilling.
9. Oil drilling pipe (YB528-65) is a seamless steel pipe with both ends thickened internally or externally for oil drilling. There are two kinds of steel pipes: turning wire and non-turning wire. Turning wire pipes are connected with joints, while non-turning wire pipes are connected with tool joints by butt welding.
10. carbon steel seamless steel pipe for ships (GB5213-85) is a carbon steel seamless steel pipe for manufacturing class I and class ii pressure-resistant pipes, boilers and superheaters of ships. The working temperature of carbon steel seamless steel pipe wall shall not exceed 450℃, and that of alloy steel seamless steel pipe wall shall exceed 450℃.
11. seamless steel pipe for automobile half-axle sleeve (GB3088-82) is a hot-rolled seamless steel pipe made of high-quality carbon structural steel and alloy structural steel for automobile half-axle sleeve and axle housing.
12. high-pressure oil pipe for diesel engine (GB3093-86) is a cold-drawn seamless steel pipe for manufacturing high-pressure pipe for injection system of diesel engine.
13. seamless steel pipe with precise inner diameter for hydraulic and pneumatic cylinders (GB8713-88) is a cold-drawn or cold-rolled seamless steel pipe with precise inner diameter for manufacturing hydraulic and pneumatic cylinders.
14. Cold-drawn or cold-rolled precision seamless steel pipe (GB3639-83) is a cold-drawn or cold-rolled precision seamless steel pipe with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. Selecting precision seamless steel pipe to manufacture mechanical structure or hydraulic equipment can greatly save machining time, improve material utilization rate and improve product quality.
15. structural stainless steel seamless steel pipe (GB/T14975-1994) is a hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless steel pipe made of stainless steel, which is widely used in chemical, petroleum, textile, medical, food, machinery and other industries.
16. seamless stainless steel pipes for fluid transportation (GB/T14976-1994) are hot rolled (extruded, expanded) and cold drawn (rolled) seamless stainless steel pipes for fluid transportation.
17. Special-shaped seamless steel pipe is the general name of seamless steel pipe with cross-sectional shape other than round pipe. According to the different shapes and sizes of steel pipe sections, it can be divided into special-shaped seamless steel pipes with equal wall thickness (code name D), special-shaped seamless steel pipes with unequal wall thickness (code name BD) and special-shaped seamless steel pipes with variable diameter (code name BJ). Special-shaped seamless steel pipes are widely used in various structural parts, tools and mechanical parts. Compared with round pipes, special-shaped pipes generally have larger moment of inertia and cross-sectional modulus, and have greater bending and torsion resistance, which can greatly reduce structural weight and save steel.
18. Seamless steel pipes for gas cylinders (GB18248-2000) are mainly used for making various gas and hydraulic cylinders. The representative materials are 37Mn, 34Mn2V, 35CrMo, etc.
Uses: Seamless steel pipes are widely used.
1. Seamless steel pipes for general use are rolled by ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output, and are mainly used as pipelines or structural parts for conveying fluids.
2. According to different uses, there are three types of supplies: A, according to the chemical composition and mechanical properties of supply; B, supply according to mechanical properties; C, according to the hydrostatic test supply. Steel pipes supplied according to Class A and Class B, if used to bear liquid pressure, shall also be subjected to water pressure test.
3. Seamless pipes for special purposes include seamless pipes for boilers, seamless steel pipes for geology and seamless pipes for petroleum.