Seamless steel tubes are made of a single piece of metal and have no seams on the surface. They are called seamless steel tubes. According to the production method, seamless pipes are divided into hot rolled pipes, cold rolled pipes, cold drawn pipes, extruded pipes, jacking pipes, etc. According to the cross-sectional shape, seamless steel tubes can be divided into two types: round and irregular. Special-shaped tubes include square, oval, triangular, hexagonal, melon-shaped, star-shaped, and finned tubes. The maximum diameter is 650mm and the minimum diameter is 0.3mm. Depending on the application, there are thick-walled tubes and thin-walled tubes. Seamless steel tubes are mainly used as petroleum geological drilling tubes, cracking tubes for petrochemicals, boiler tubes, bearing tubes, and high-precision structural steel tubes for automobiles, tractors, and aviation.
Steel pipe without seams along the perimeter of its cross section. According to different production methods, it is divided into hot-rolled tube, cold-rolled tube, cold-drawn tube, extruded tube, jacking tube, etc., each with its own process regulations. Materials 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 acid-resistant steel, etc. According to usage, it is divided into general purpose (for water transmission, gas pipelines and structural parts, mechanical parts) and special (for boilers, geological exploration, bearings, acid resistance, etc.).
Seamless steel tubes are widely used. The general-purpose seamless steel tubes are rolled from ordinary carbon structural steel, low-alloy structural steel or alloy structural steel, with the largest output, and are mainly used as pipes or structural parts for conveying fluids. .2. Supply is divided into three categories according to different uses: a. Supply according to chemical composition and mechanical properties; b. Supply according to mechanical properties; c. Supply according to hydraulic test. Steel pipes supplied according to categories a and b are also subject to hydrostatic tests if they are used to withstand liquid pressure. 3. Seamless pipes for special purposes include seamless pipes for boilers, chemical power, seamless steel pipes for geology and seamless pipes for petroleum.
Seamless steel tubes have hollow cross-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 round steel and other solid steels, steel pipes are lighter in weight and have a lower flexural and torsional strength, and are an economic cross-section steel.
Widely used in the manufacture of structural parts and mechanical parts, such as petroleum drill pipes, automobile transmission shafts, bicycle racks and steel scaffolds used in construction, etc., to make ring parts with steel pipes, which can improve material utilization, simplify manufacturing processes, save materials and processing Working hours have been widely manufactured with steel pipes.
