Mode of production
Stainless steel pipe can be divided into seamless pipe and welded pipe according to the production mode. Seamless steel pipe can be divided into hot-rolled pipe, cold-rolled pipe, cold drawn pipe and extruded pipe. Cold drawing and cold rolling are the secondary processing of steel pipe; Welded pipe is divided into straight seam welded pipe and spiral welded pipe.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, bimetallic composite pipes, coated and coated pipes to save precious metals and meet special requirements. Stainless steel pipes have a wide variety, different uses, different technical requirements and different production methods. At present, the outer diameter range of steel pipes is 0.1-4500mm and the wall thickness range is 0.01-250mm. In order to distinguish its characteristics, steel pipes are usually classified according to the following methods.Section shape
Stainless steel pipe can be divided into round pipe and special-shaped pipe according to the cross-sectional shape. Special shaped tubes include rectangular tubes, rhombic tubes, elliptical tubes, hexagonal tubes, octagonal tubes and various cross-section asymmetric tubes. Special shaped pipe is widely used in various structural parts, tools and mechanical parts. Compared with circular pipe, special-shaped pipe generally has large moment of inertia and section modulus, and has large bending and torsion resistance, which can greatly reduce the structural weight and save steel. Stainless steel pipe can be divided into equal section pipe and variable section pipe according to the profile shape. Variable section pipes include conical pipes, stepped pipes and periodic section pipes.Pipe end shape
Stainless steel pipe can be divided into smooth pipe and threaded pipe (threaded steel pipe) according to the state of pipe end. Threading pipe can also be divided into ordinary threading pipe (pipe for conveying low pressure such as water and gas, which is connected by ordinary cylindrical or conical pipe thread) and special threaded pipe (pipe for petroleum and geological drilling, which is connected by special thread for important threading pipe). For some special pipes, in order to make up for the impact of thread on the strength of pipe end, pipe end thickening (internal thickening External thickening or internal and external thickening).Use classification
According to the purpose, it can be divided into oil well pipe (casing, oil pipe and drill pipe), pipeline pipe, boiler pipe, mechanical structure pipe, hydraulic prop pipe, gas cylinder pipe, geological pipe, chemical pipe (high-pressure fertilizer pipe, petroleum cracking pipe) and marine pipe.Production
Production process of stainless steel welded pipe: Raw materials -- strip splitting -- welded pipe making -- end repair -- polishing -- Inspection (spray printing) -- Packaging -- delivery (warehousing) (decorative welded pipe). Raw materials -- strip splitting -- welded pipe making -- heat treatment -- Correction -- straightening -- end repair -- pickling -- Hydrostatic Test -- Inspection (spray printing) - packaging -- delivery (warehousing) (pipes for welded pipe industrial piping).