What is seamless steel pipe
Seamless steel pipes are perforated from a whole round steel, and the steel pipes without welds on the surface are called seamless steel pipes. 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 jacking pipes. According to the cross-sectional shape, seamless steel pipes are divided into two types: round and special-shaped. Special-shaped pipes including square, oval, triangle, hexagon, melon seed, star, and finned shape pipes. The maximum diameter is 900mm and the minimum diameter is 4mm. According to different usages, there are thick-walled seamless steel pipes and thin-walled seamless steel pipes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, petrochemical cracking pipes, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation.
Classification of seamless steel pipes
According to different production methods, seamless steel pipe can be divided into hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe, jacking pipe, etc., all of them have their own process regulations.
According to the materials, there are ordinary and high-quality carbon structural steel (Q215-A～Q275-A and #10～50 steel), low alloy steel (09MnV, 16Mn, etc.), alloy steel, stainless and acid-resistant steel, etc.
According to the purpose, it is divided into two categories: general purpose (used for water, gas pipelines and structural parts, mechanical parts) and special purpose (used for boilers, geological prospecting, bearings, acid resistance, etc.).
Usage of seamless steel pipe
- General-purpose seamless steel pipes: they are rolled from 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.
- Special-purpose seamless pipes: they include seamless pipes for boilers, chemical and electric power, seamless steel pipes for geology, and seamless pipes for petroleum.
Seamless steel pipes have a hollow section and are used in large quantities as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, steel pipe; it has a lighter weight when the bending and torsion strength is the same, and it is an economical section steel.
Widely used in the manufacture of structural parts and mechanical parts, such as ring parts for oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction, which can improve material utilization, simplify manufacturing procedures, and save materials and processing working hours, seamless steel pipes have been widely used for manufacturing.