Export Astm A790/SA790 Stainless Steel Duplex Seamless Pipe

Astm A790/SA790 Stainless Steel Duplex Seamless Pipe

ASTM A790/ASME SA790 stainless steel duplex seamless pipes are high – performance pipes designed for a wide range of applications that demand excellent corrosion resistance and mechanical strength. These pipes are manufactured in accordance with the ASTM A790 and ASME SA790 standards, which specify strict requirements regarding their chemical composition, mechanical properties, and manufacturing processes.

Chemical Composition

The duplex stainless steel used in these pipes has a unique chemical composition. It typically contains elements such as chromium (Cr), nikl (Ni), molybdenum (Mo), and nitrogen (N). For example, in the common S31803 grade:

– Chromium content usually ranges from 21.0% – 23.0%. Chromium is crucial for forming a passive oxide layer on the surface of the pipe, which provides corrosion resistance.

– Nickel content is around 4.5% – 6.5%. Nickel enhances the austenitic phase formation in the duplex structure and improves toughness and corrosion resistance in various environments.

– Molybdenum, with a content of 2.5% – 3.5%, further boosts the pipe’s resistance to pitting and crevice corrosion, especially in chloride – rich environments.

– Nitrogen, present in the range of 0.08% – 0.20%, increases the strength of the steel and also contributes to its corrosion – resistant properties.

Mechanical Properties

1. High Strength: ASTM A790/SA790 duplex seamless pipes exhibit high yield and tensile strength. For instance, in the S31803 grade, the minimum yield strength is 450 MPa, and the minimum tensile strength is 620 MPa. This high strength allows the pipes to withstand high – pressure applications without significant deformation or failure.

2. Good Ductility: Despite their high strength, these pipes also have good ductility, with a minimum elongation of 25% in a 2 – inch or 50 – mm gauge length. This property enables them to be formed and fabricated into different shapes and sizes during manufacturing and installation processes.

3. Toughness: They maintain good toughness even at low temperatures, making them suitable for applications in cold environments, such as in the Arctic regions for oil and gas pipelines.

ASTM A790/ASME SA790 stainless steel duplex seamless pipes Manufacturing Process

1. Seamless Manufacturing: The seamless manufacturing process ensures that there are no welded joints in the pipe, which eliminates potential weak points. This is achieved through processes like hot – válcování, piercing, and cold – drawing. During hot – válcování, the billet is heated to a high temperature and passed through a series of rolls to reduce its diameter and increase its length. Piercing is then used to create a hollow center in the hot – rolled billet. Cold – drawing further refines the dimensions and improves the surface finish and mechanical properties of the pipe.

2. Quality Control: Throughout the manufacturing process, strict quality control measures are implemented. Chemical analysis is carried out to ensure that the chemical composition of the steel meets the ASTM A790/SA790 standards. Mechanical tests, including tensile tests, hardness tests, and flattening tests, are also performed to verify the mechanical properties of the pipes. Nondestructive testing methods, such as ultrasonic testing and eddy – current testing, are used to detect any internal or surface defects.

Applications

1. Used in Oil and Gas Industry: These pipes are extensively used in the oil and gas industry for various applications. In offshore oil and gas production, they are used in subsea pipelines to transport oil and gas from the wells to the platforms. Their high corrosion resistance to seawater and the aggressive chemicals present in oil and gas fluids ensures the integrity and long – term operation of the pipelines. They are also used in onshore oil and gas processing facilities, such as in separators, reactors, and storage tanks.

2. Chemical Processing Industry: In chemical plants, where pipes are exposed to a wide range of corrosive chemicals, ASTM A790/SA790 duplex seamless pipes are an ideal choice. They can withstand the harsh conditions of acids, alkalis, and other corrosive substances used in chemical reactions and processing. For example, in the production of fertilizers, petrochemicals, and pharmaceuticals, these pipes are used to transport raw materials, intermediate products, and finished products.

3. Desalination Plants: With the increasing demand for fresh water, desalination plants play a crucial role. The pipes in desalination plants are constantly exposed to seawater, which is highly corrosive. The excellent corrosion – resistant properties of ASTM A790/SA790 duplex seamless pipes make them suitable for use in the intake, pretreatment, and distribution systems of desalination plants, ensuring the reliable operation of the plants and the production of high – quality fresh water.

4. The duplex stainless steel pipes can resist the corrosion caused by these chemicals, extending the service life of the pipes and reducing maintenance and replacement costs in pulp and paper mills.

Advantages over Other Materials

1. Corrosion Resistance: Compared to traditional carbon steel pipes, ASTM A790/SA790 duplex seamless pipes offer significantly better corrosion resistance. They can resist pitting, crevice corrosion, and stress – corrosion cracking, which are common forms of corrosion in many industrial environments. In comparison to some austenitic stainless steel pipes, například 304 and 316L, they have enhanced resistance to stress – corrosion cracking in chloride – containing environments.

2. Strength – to – Weight Ratio: Their high strength allows for the use of thinner – walled pipes in many applications, reducing the overall weight of the piping system. This not only saves on material costs but also makes installation and transportation easier. For example, in a large – scale industrial project, using these high – strength duplex pipes can lead to significant savings in construction time and costs associated with handling heavy materials.

3. Cost – Effectiveness in the Long Run: Although the initial cost of ASTM A790/SA790 duplex seamless pipes may be higher than some lower – grade materials, their long – term cost – effectiveness is evident. Their resistance to corrosion and high mechanical strength result in fewer maintenance and replacement requirements, reducing the total cost of ownership over the lifespan of the piping system.

Conclusion

ASTM A790/SA790 stainless steel duplex seamless pipes are a reliable and high – performance choice for a variety of industries. Their unique combination of chemical composition, excellent mechanical properties, and outstanding corrosion resistance makes them suitable for applications where durability, spolehlivost, and safety are of utmost importance.

304L stainless steel pipe 304L nerezová bezešvá trubka 310S stainless steel pipes 904L stainless steel pipe 904L stainless steel tubes 2205 2205 trubka z nerezové oceli 2205 nerezová bezešvá trubka 2507 duplexní trubka z nerezové oceli 2507 trubka z nerezové oceli 2507 nerezová bezešvá trubka 2520 stainless steel tubes AStm A312 stainless stael pipe Specifikace potrubí z nerezové oceli ASTM A312 ASTM A312 STAINLESS STEEL SEAMLESS PIPE ASTM A312 TP304 NEREZOVÁ BEZPELOVÁ TRUBKA ASTM A312 TP316L STAINLESS STEEl PIPE Astm a554 stainless steel pipe birmingham wire gauge BWG Bwg Sizes bwg tube duplexní trubka z nerezové oceli gauge bwg trubice tepelného výměníku inox press fittings cena sanitary seamless pipe sanitární potrubí z nerezové oceli sanitary stainless steel tubes Sizes Chart Trubka z nerezové oceli stainless steel pipefitting nerezové trubky stainless steel sanitary tubes nerezová bezešvá trubka bezešvé trubky z nerezové oceli trubka z nerezové oceli svařovaná trubka z nerezové oceli standard wire gauge Super Austenitic 904L z nerezové oceli Tp304 trubka z nerezové oceli TP304L Stainless steel seamless pipe Trubice Čína tube sizing chart