Details of ASTM A312-21 straight seam stainless steel pipes commonly used in industrial projects

First, details of ASTM A312 straight seam stainless steel pipes
Stainless steel welded pipes: Stainless steel welded pipes are also called welded pipes. They are made of steel plates or strips that are welded after curling and forming. They are generally 6 meters long. Welded steel pipes have simple production processes, high production efficiency, a wide variety of specifications, and low equipment investment, but their strength is generally lower than that of seamless steel pipes.
Stainless steel pipes: Stainless steel pipes are a type of hollow, long, round steel that is widely used in industrial pipelines and mechanical structural components such as petroleum, chemical, medical, food, light industry, and mechanical instruments. In addition, when the bending and torsional strengths are the same, the weight is lighter, so it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used in furniture and kitchenware.

Second, the material of ASTM A312 straight seam stainless steel pipes
(1) National standard material: 1Cr17Mn6Ni5N, 1Cr18Mn8Ni5N, 1Cr17Ni7, 0Cr18Ni9, 00Cr19Ni10, 0Cr19Ni9N, 0Cr19Ni10NbN, 00Cr18Ni10N, 1Cr18Ni12, 0Cr23Ni13, 0Cr25Ni20, 0Cr17Ni12Mo2, 0Cr18Ni12Mo3Ti, 00Cr17Ni14Mo2, 0Cr17Ni12Mo2N, 00Cr17N i13Mo2N, 0Cr18Ni12Mo2Cu2, 00Cr18Ni14Mo2Cu2, 0Cr19Ni13Mo3, 00Cr19Ni13Mo3, 0Cr18Ni10Ti, 0Cr18Ni11Nb, 0C r26Ni5Mo2, 00Cr18Ni5Mo3Si2, 1Cr12, 1Cr13, 2Cr13, 3Cr13, 7Cr17, 0Crl3Al, 00Cr12, 1Cr17, 1Cr17Mo, 00Cr18Mo2.
(2) New national standard material: 12Cr17Mn6Ni5N, 12Cr18Mn9Ni5N, 12Cr17Ni7, 06Cr19Ni10, 022Cr19Ni10, 06Cr19Ni10N, 06Cr19Ni9NbN, 022Cr19Ni10N, 10Cr18Ni12, 06Cr23Ni13, 06Cr25Ni20, 06Cr17Ni12Mo2, 06Cr17Ni12Mo2Ti, 022Cr17Ni12Mo2, 06Cr17Ni12Mo2N, 022Cr17Ni13Mo2N , 06Cr18Ni12Mo2Cu2, 022Cr18Ni14Mo2Cu2, 06Cr19Ni13Mo3, 022Cr19Ni13Mo3, 06Cr18Ni11Ti, 06Cr18Ni11Nb, 022Cr19Ni5Mo3Si2 N, 12Cr12, 12Cr13, 20Cr13, 30Cr13, 68Cr17, 06Crl3Al, 022Cr11Ti, 022Cr12, 10Cr17, 10Cr17Mo, 022Cr18NbTi, 019Cr19Mo2NbTi.
(3) Japanese standard materials: SUS201, SUS202, SUS301, SUS304, SUS304L, SUS304N1, SUS304N2, SUS304LN, SUS305, SUS309S, SUS310S, SUS316, SUS316Ti, SUS316L, SUS316N, SUS316LN, SUS316J1, SUS316J1L, SUS317, SUS317L, SUS321, SUS347, SUS329J1, SUS329J3, SUS403, SUS410, SUS420J1, SUS420J2, SUS440A, SUS405, SUH409, SUS410L, SUS430, SUS434, SUS444.
(4) American standard materials: 201, 202, 301, 304, 304J1, 304L, 304N, XM21, 304LN, 305, 309S, 310S, 316, 316L, 316N, 316LN, 317, 317L, 321, 347, 329, 403, 410, 420, 440A, 405, 409, 410L, 430, 439, 434, 444.
(5) High corrosion resistant steel alloys: NAS 185N (254SMO), NAS 254N, NAS 254NM (AL6XN), NAS 255 (AL904L), NAS 255NM, NAS 354N, NAS 329J3L (S32205 duplex steel), NAS 64, INCOLOY 825, INCONEL 625, INCONEL 690, HASTELLOY C-22, C-276, MONEL400/K-500, Alloy 718; Heat resistant steel alloys: INCOLOY 800/800H/800HT, INCOLOY 840, INCONEL 600, INCONEL 601, NAS 660 (A-286), INCONEL X-750, NAS HX (HASTELLOY X); Precipitation hardening stainless steel: NAS 630 (17-4PH), NAS 631 (17-7PH), NAS NM15M;, Imported/domestic austenitic stainless steel: 304, 304L, 316, 316L, 316TI, 317L, 310S, 321, 253MA

Third, the performance of ASTM A312 straight seam stainless steel pipe
(1) Hardness: Stainless steel pipes are generally measured by three hardness indicators: Brinell, Rockwell, and Vickers.
(2) Brinell hardness: In stainless steel pipe standards, Brinell hardness is the most widely used, and 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.
(3) Rockwell hardness: The Rockwell hardness test of stainless steel pipes is the same as the Brinell hardness test, both of which are indentation test methods. 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 the Brinell hardness HB in the steel pipe standard. 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 hardness tester dial. However, due to its small indentation, the hardness value is not as accurate as the Brinell method.
(4) 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.
(5) Hardness test: For annealed stainless steel pipes with an inner diameter of more than 6.0 mm and a wall thickness of less than 13 mm, the W-B75 Vickers hardness tester can be used. It is very fast and simple to test and is suitable for fast and non-destructive qualified inspection of stainless steel pipes. For stainless steel pipes with an inner diameter greater than 30 mm and a wall thickness greater than 1.2 mm, the Rockwell hardness tester is used to test the 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.

Fourth, the process of ASTM A312 straight seam stainless steel pipe
a. Round steel preparation;
b. Heating;
c. Hot rolling piercing;
d. Head cutting;
e. Pickling;
f. Grinding;
g. Lubrication;
h. Cold rolling processing;
i. Degreasing;
j. Solution heat treatment;
k. Straightening;
l. Pipe cutting;
m. Pickling;
n. Finished product inspection.

Fifth, the classification of ASTM A312 straight seam stainless 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, with different uses, different technical requirements, and different production methods. The outer diameter range of the steel pipes currently produced is 0.1-4500mm, and the wall thickness range is 0.01-250mm. To distinguish their characteristics, steel pipes are usually classified according to the following methods.

Sixth, the production method of ASTM A312 straight seam stainless steel pipes
Raw materials--striping--welding pipe making--end trimming--polishing--inspection (printing)--packaging--shipping (warehousing) (decorative welded pipes).
Raw materials--stripping--welding pipe making--heat treatment--correction--straightening--end trimming--pickling--hydraulic pressure testing--inspection (printing)--packaging--shipping (warehousing) (pipes for industrial piping of welded pipes).

Seventh, the cross-sectional shape of ASTM A312 straight seam stainless steel pipes
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 cross-sectional 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 conical pipes, stepped pipes, and periodic cross-section pipes.

Eighth, the shape of the pipe end of ASTM A312 straight seam stainless 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 low pressure such as water and gas, connected by ordinary cylindrical or conical pipe threads) and special threaded pipes (pipes for petroleum and geological drilling, and special threaded connections for important threaded pipes). For some special pipes, to compensate for the influence of threads on the strength of the pipe ends, the pipe ends are usually thickened before threading (internal thickening, external thickening, or internal and external thickening).

Ninth, the classification of the use of ASTM A312 straight seam stainless 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.