Stainless steel welded pipe is a tubular product made by curling, forming and welding stainless steel plates or strips. The production process of stainless steel welded pipe is simple, with high production efficiency, many varieties and specifications, and low equipment investment, but the general strength is lower than that of seamless steel pipe. What are the implementation standards of stainless steel welded pipe? What is the production process of stainless steel welded pipe?
What are the implementation standards for stainless steel welded pipes?
1. GB/T 12771-2024
This is the latest implementation standard for stainless steel welded pipes, which stipulates the classification, specifications, material requirements, manufacturing process and quality control requirements of stainless steel welded pipes. Stainless steel welded pipes are divided into four types: austenitic stainless steel welded pipes, ferritic stainless steel welded pipes, austenitic-ferritic stainless steel welded pipes and high alloy stainless steel welded pipes. The standard also specifies in detail the test methods for stainless steel welded pipes, including surface quality, mechanical properties, chemical composition, non-destructive testing, pressure testing, etc.
2. GB/T 12771-2008
Although GB/T 12771-2024 has replaced this standard, GB/T 12771-2008 was previously widely used to guide the production and quality control of stainless steel welded pipes for fluid transportation. This standard mainly stipulates the technical requirements, test methods, inspection rules, packaging, marking and quality certificates of stainless steel welded pipes for fluid transportation. It is mainly used for conveying low-pressure corrosive media. Representative materials include 06Cr19Ni10, 022Cr19Ni10, 06Cr19Ni110Ti, 00Cr17, 0Cr18Ni11Nb, 06Cr17Ni12Mo2, etc.
3、GB/T 12770-2012
This standard applies to stainless steel welded steel pipes for mechanical structures, which are mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.
In addition, there are other implementation standards related to stainless steel welded pipes, such as GB/T 14976-2012 "Stainless steel seamless pipes for fluid transportation" and GB/T 20833-2008 "Austenitic-ferritic duplex stainless steel seamless pipes". These standards put forward different technical requirements and quality control measures for different types of steel pipes to ensure the performance and safety and reliability of steel pipes in various use environments.
Stainless steel welded pipes production process
1. Raw material preparation
Select high-quality stainless steel plates as raw materials, and perform cutting, leveling and cleaning to ensure the quality of the raw materials.
2. Rolling
The cut stainless steel sheet is rolled through a rolling machine to form a tube.
3. Welding
The rolled stainless steel pipes are welded. Common welding methods include arc welding, TIG welding and high-frequency welding. The welds must be deoxidized and cleaned to improve the welding strength and quality.
4. Cold drawing
The welded stainless steel pipe is cold drawn, that is, the pipe is placed in a cold drawing machine for drawing, thereby improving the dimensional accuracy and surface finish of the pipe.
5. Pickling
The pickling method is used to remove the oxide layer and welding slag on the surface of the pipe, making the surface of the pipe smoother and improving its corrosion resistance.
6. Annealing
The pickled pipe is annealed, that is, it is kept at high temperature for a certain period of time to make the internal structure of the pipe uniform, eliminate the stress generated during welding, and improve the physical properties of the pipe.
7. Flattening
The annealed stainless steel tube is flattened, that is, the tube is flattened into the required shape and size by a press.
8. Cutting
According to the customer's requirements, the flattened stainless steel pipe is cut to the required length.
9. Inspection
Perform appearance inspection and dimensional inspection on the cut stainless steel pipes to ensure that the quality and dimensional accuracy of the pipes meet the standard requirements.
10. Packaging and storage
The stainless steel pipes that have passed the inspection are packaged. Common packaging methods include plastic bag packaging and wooden box packaging to protect the pipes from external damage and store them.
Read more: Characteristics and Types of Stainless Steel Welded Pipes
