According to the production method, seamless pipes are divided into hot-rolled seamless steel pipes, cold-rolled pipes, cold-drawn pipes, extruded pipes, jacked pipes, etc. According to the cross-sectional shape, seamless steel pipes are divided into two types: round and special-shaped. Special-shaped pipes have various complex shapes such as square, oval, triangle, hexagon, melon-shaped, star-shaped, and finned pipes. The maximum diameter is 650mm and the minimum diameter is 0.3mm. According to different uses, there are thick-walled tubes and thin-walled tubes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemical industry, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation.
Seamless steel pipes are widely used. General-purpose seamless steel pipes are rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel. They have the largest output and are mainly used as pipes or structural parts for conveying fluids. .2. They are supplied in three categories according to different uses: a. Supplied according to chemical composition and mechanical properties; b. Supplied according to mechanical properties; c. Supplied according to hydraulic pressure test. If the steel pipes supplied according to categories a and b are used to withstand liquid pressure, they must also undergo a hydrostatic test. 3. Special-purpose seamless pipes include seamless pipes for boilers, chemical and electric power, geological seamless pipes, and petroleum seamless pipes.
Seamless steel pipes have hollow sections and are widely used as pipelines for transporting fluids, such as pipelines for transporting oil, natural gas, coal gas, water and certain solid materials. Compared with solid steel materials such as round steel, steel pipes are lighter in weight when the bending and torsional strength is the same, and they are an economical cross-section steel material.
It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction. The use of steel pipes to make ring parts can improve material utilization, simplify the manufacturing process, and save materials and processing. Steel pipes have been widely used for manufacturing.
