Stainless steel pipes are divided into ordinary carbon steel pipes, high-quality carbon structural steel pipes, alloy structural pipes, alloy steel pipes, bearing steel pipes, stainless steel pipes, and bimetal composite pipes, plating and coating pipes to save precious metals and meet special requirements. . There are many types of stainless steel pipes, their uses are different, their technical requirements are different, and their production methods are also different. The currently produced steel pipes have an outer diameter range of 0.1-4500mm and a wall thickness range of 0.01-250mm. In order to distinguish its characteristics, steel pipes are usually classified as follows.
ways to produce
Stainless steel pipes are divided into seamless pipes and welded pipes according to the production method. Seamless steel pipes can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes and extruded pipes. Cold-drawn and cold-rolled are the secondary types of steel pipes. Processing; welded pipe is divided into straight seam welded pipe and spiral welded pipe.
Stainless steel pipes can be divided into round pipes and special-shaped pipes according to the cross-sectional shape. Special-shaped tubes include rectangular tubes, rhombus tubes, oval tubes, hexagonal tubes, octagonal tubes, and various asymmetrical cross-section tubes. Special-shaped tubes are widely used in various structural parts, tools and mechanical parts. Compared with round pipes, special-shaped pipes generally have larger moments of inertia and section modulus, and have greater resistance to bending and torsion, which can greatly reduce structural weight and save steel.
Stainless steel pipes can be divided into equal-section pipes and variable-section pipes according to the shape of the longitudinal section. Variable section tubes include tapered tubes, stepped tubes and periodic section tubes.
Tube end shape
Stainless steel pipes can be divided into smooth pipes and threaded pipes (threaded steel pipes) according to the state of the pipe ends. The threaded pipe can be divided into ordinary threaded pipe (pipes for conveying water, gas and other low pressure, which are connected by ordinary cylindrical or tapered pipes) and special threaded pipes (pipes for petroleum and geological drilling. For important threaded pipes, use Special thread connection). For some special pipes, in order to compensate for the influence of the thread on the strength of the pipe end, the pipe end is usually thickened (internal thickening, external thickening or internal and external thickening) before turning the wire.
According to the purpose, it can be divided into oil well pipes (casing, tubing and drill pipes, etc.), line pipes, boiler pipes, mechanical structure pipes, hydraulic prop pipes, gas cylinder pipes, geological pipes, chemical pipes (high pressure fertilizer pipes, petroleum cracking pipes, etc.) ) And ship pipes.
Stainless steel welded pipe production process:
Raw material-slitting-welding pipe-trimming-polishing-inspection (spray printing)-packaging-shipping (warehouse) (decorative welded pipe).
Raw material–Slitting–Welding pipe–Heat treatment–Straightening–Straightening–End trimming–Pickling–Hydraulic pressure test–Inspection (printing)–Packaging–shipping (warehousing) (Pipe for industrial piping of welded pipe).