Seamless steel pipes are perforated from a whole round steel, and steel pipes without welds on the surface are called seamless steel pipes. 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 jacks according to production methods. Seamless steel pipes are divided into two types: round and special-shaped according to their cross-sectional shape. Special-shaped tubes include square, elliptical, triangular, hexagonal, melon-shaped, star-shaped, and finned tubes. The maximum diameter is 900mm and the minimum diameter is 4mm. According to different purposes, 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.
Seamless steel pipes are widely used.
1. General-purpose seamless steel pipes 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.
2. According to different purposes, it can be divided into three categories:
A sort of. Supply according to chemical composition and mechanical properties;
Bay according to mechanical performance;
C. According to the water pressure test supply. Steel pipes are supplied in categories A and B. If it is used to withstand liquid pressure, a hydraulic test should also be carried out.
3. Seamless pipes for special purposes include seamless pipes for boilers, chemicals, 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 has lighter bending and torsion strength and is an economical section steel. Widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, steel scaffolding for construction, etc. Making ring parts with steel pipes can improve material utilization, simplify manufacturing procedures, and save materials and processing. operating hours.
There are two main production processes for seamless steel pipes (cold rolling and hot rolling):
①Main production process of hot-rolled seamless steel pipe (△main inspection process):
Tube blank preparation and inspection △→tube heating→perforation→rolling tube→tube reheating→fixed (reduced) diameter→heat treatment△→finished tube straightening→finishing→inspection△(non-destructive, physical and chemical, bench inspection)→in storage
②The main production process of cold-rolled seamless steel pipe:
Blank preparation → pickling and lubrication → cold rolling (drawing) → heat treatment → straightening → finishing → inspection → storage
Post time: Nov-02-2021