S31254 stainless steel pipe is a hollow long round steel, which is widely used in industrial pipelines such as petroleum, chemical, medical, food, light industry, mechanical instruments, and mechanical structural components. In addition, when the bending and torsional strengths are the same, the weight is light, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used as furniture and kitchen utensils.
First, the production of S31254 stainless steel straight seam welded steel pipe
(1) Stainless steel welded pipe production process:
(a) Raw materials–striping–welding pipe making–end trimming–polishing–inspection (spray printing)–packaging–shipping (warehousing) (decorative welded pipe).
(b) Raw materials–striping–welding pipe making–heat treatment–correction–straightening–end trimming–pickling–hydraulic pressure testing–inspection (spray printing)–packaging–shipping (warehousing) (welded pipe industrial piping pipe).
(2) Production method: Stainless steel pipes are divided into two categories according to the production method: seamless pipes and welded pipes. Seamless steel pipes can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes, and extruded pipes. Cold drawing and cold rolling are secondary processing of steel pipes; welded pipes are divided into straight seam welded pipes and spiral welded pipes.
Process
Second, the hardness of S31254 stainless steel straight seam welded steel pipe: Stainless steel pipes are generally measured by three hardness indicators: Brinell, Rockwell, and Vickers.
(1) Brinell hardness: In stainless steel pipe standards, Brinell hardness is the most widely used. The hardness of the material is often expressed by the indentation diameter, which is both intuitive and convenient. However, it does not apply to steel pipes made of harder or thinner steel.
(2) Rockwell hardness: The Rockwell hardness test of stainless steel pipes is the same as the Brinell hardness test, which is an indentation test method. The difference is that it measures the depth of the indentation. The Rockwell hardness test is currently a widely used method, among which HRC is second only to Brinell hardness HB in steel pipe standards. Rockwell hardness can be used to measure metal materials from extremely soft to extremely hard. It makes up for the shortcomings of the Brinell method. It is simpler than the Brinell method and the hardness value can be read directly from the dial of the hardness tester. However, due to its small indentation, the hardness value is not as accurate as the Brinell method.
(3) Vickers hardness: The Vickers hardness test of stainless steel pipes is also an indentation test method, which can be used to measure the hardness of very thin metal materials and surface layers. It has the main advantages of the Brinell and Rockwell methods and overcomes their basic disadvantages, but it is not as simple as the Rockwell method. The Vickers method is rarely used in steel pipe standards.
(4) Hardness test: Annealed stainless steel pipes with an inner diameter of more than 6.0 mm and a wall thickness of less than 13 mm can be tested with the W-B75 Vickers hardness tester. It is very fast and simple to test and is suitable for fast and non-destructive qualified inspection of stainless steel pipes. Stainless steel pipes with an inner diameter greater than 30 mm and a wall thickness greater than 1.2 mm can be tested with a Rockwell hardness tester to test HRB and HRC hardness. For stainless steel pipes with an inner diameter greater than 30mm and a wall thickness less than 1.2mm, a surface Rockwell hardness tester is used to test the HRT or HRN hardness. For stainless steel pipes with an inner diameter of less than 0mm and greater than 4.8mm, a special Rockwell hardness tester for pipes is used to test the HR15T hardness. When the inner diameter of the stainless steel pipe is greater than 26mm, the hardness of the inner wall of the pipe can also be tested with a Rockwell or surface Rockwell hardness tester.
Third, the classification of S31254 stainless steel straight seam welded steel pipes: 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 bimetallic composite pipes, plating and coating pipes to save precious metals and meet special requirements. There are many types of stainless steel pipes, different uses, different technical requirements, and different production methods. The outer diameter of the steel pipes currently produced ranges from 0.1 to 4500mm and the wall thickness ranges from 0.01 to 250mm. In order to distinguish their characteristics, steel pipes are usually classified according to the following methods.
Fourth, the cross-sectional shape of S31254 stainless steel straight seam welded steel pipe: stainless steel pipes can be divided into round pipes and special-shaped pipes according to the cross-sectional shape. Special-shaped pipes include rectangular pipes, diamond pipes, elliptical pipes, hexagonal pipes, octagonal pipes, and various asymmetric pipes. Special-shaped pipes 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 moduli, and have greater bending and torsion resistance, which can greatly reduce the weight of the structure and save steel. Stainless steel pipes can be divided into equal-section pipes and variable-section pipes according to the longitudinal section shape. Variable-section pipes include tapered pipes, stepped pipes, and periodic-section pipes.
Fifth, the pipe end shape of S31254 stainless steel straight seam welded steel pipe: stainless steel pipes can be divided into plain pipes and threaded pipes (threaded steel pipes) according to the state of the pipe ends. Threaded pipes can be divided into ordinary threaded pipes (pipes for conveying water, gas, etc. at low pressure, connected by ordinary cylindrical or conical pipe threads) and special threaded pipes (pipes for petroleum and geological drilling, special threaded connections are used for important threaded pipes). For some special pipes, in order to compensate for the influence of threads on the strength of the pipe ends, the pipe ends are usually thickened before threading (inner thickening, outer thickening, or inner and outer thickening).
Sixth, the use classification of S31254 stainless steel straight seam welded steel pipes: according to the use, they can be divided into oil well pipes (casing, oil pipes drill pipes, etc.), pipeline pipes, boiler pipes, mechanical structure pipes, hydraulic support pipes, gas cylinder pipes, geological pipes, chemical pipes (high-pressure fertilizer pipes, petroleum cracking pipes) and ship pipes, etc.
Post time: May-29-2025