Details of ASTMA790 Duplex Stainless Steel Pipe

Before we delve into ASTMA790 stainless steel pipe, we first need to have a comprehensive understanding of its material background, technical specifications, application areas, and importance in modern industry. The ASTMA790 standard was developed by the American Society for Testing and Materials (ASTM) for duplex stainless steel pipes, especially those containing about 22% chromium, 3% molybdenum, 5% to 6% nickel and 0.15% to 0.25% nitrogen super duplex stainless steel, such as the famous UNSS31803 (also known as 2205) and UNSS32750 (super duplex steel). This type of steel occupies a pivotal position in many industries with its excellent corrosion resistance, high strength, and good toughness.

ASTMA790 duplex stainless steel pipe products should be confirmed to meet the requirements of TSGD7002 "Rules for Type Test of Pressure Piping Components".

ASTMA790/A790M seamless and welded ferritic/austenitic stainless steel pipe specifications.

Common product grades are: UNSS31260, UNSS31500, UNSS31803.UNSS32101, UNSS32205, UNSS32304, UNSS32750

Product outer diameter 20~762mm wall thickness 2.0~120mm

Product production method: cold rolling, cold drawing, hot rolling, welding, delivery status: heat treatment + pickling

First, technical characteristics and advantages

The reason why ASTMA790 stainless steel pipe can stand out among many materials is mainly due to its unique duplex microstructure, which is composed of about 50% austenite phase and 50% ferrite phase. This unique structure gives it a series of excellent performance characteristics:

1. Excellent corrosion resistance: The stress corrosion cracking (SCC) resistance of duplex stainless steel in a chloride environment far exceeds that of traditional austenitic stainless steel, such as 304 and 316L. In addition, it can effectively resist pitting, crevice corrosion, and general corrosion, and is particularly suitable for marine environments, chemical processing, oil and gas extraction and transportation, etc.

2. High strength: Compared with austenitic stainless steel, ASTMA790 stainless steel pipe has higher yield strength and tensile strength, which means that under the same design conditions, thinner pipes can be used, thereby reducing weight and reducing costs.

3. Good toughness: Even in low-temperature environments, duplex stainless steel can maintain good impact toughness, which makes it an ideal choice for projects in cold areas such as the Arctic.

4. Hot processing and weldability: Although the processing and welding of duplex stainless steel require specific technology and parameter control, once properly operated, its welded joints can also maintain good corrosion resistance and mechanical properties.

Second, application areas

Based on the above characteristics, ASTMA790 stainless steel pipe plays an irreplaceable role in many key industries:

-Oil and gas industry: used for submarine oil and gas pipeline transportation systems, oil and gas field gathering pipelines, oil and gas separators, processing equipment, etc., effectively resisting the corrosion of seawater and oil and gas.

-Chemical processing: In corrosive media such as strong acids and alkalis, ASTMA790 pipes are ideal materials for manufacturing equipment such as reactors, storage tanks, pipelines, and valves.

-Desalination and water treatment: In desalination devices, desalination systems, and wastewater treatment facilities, its corrosion resistance ensures the long-term stable operation of the equipment.

-Pulp and papermaking: In processes such as pulp bleaching, cooking, and washing, duplex stainless steel can effectively resist the erosion of chemical agents and extend the service life of the equipment.

-Ship and marine engineering: Used to manufacture hull structures, seawater cooling systems, ballast tanks, cargo tanks, etc., to resist seawater erosion and the attachment of marine organisms.

Third, material selection and manufacturing

When selecting ASTMA790 stainless steel pipes, in addition to considering their basic chemical composition and mechanical properties, it is also necessary to pay attention to their manufacturing process, heat treatment status, and surface quality. During the manufacturing process, the chemical composition must be strictly controlled to ensure the balance of the duplex structure; at the same time, through appropriate heat treatment processes, the organizational structure can be further optimized to improve the performance of the material. In addition, good surface quality is also one of the important factors to ensure the corrosion resistance of the pipe.

Fourth, Summary

In summary, ASTMA790 stainless steel pipes have shown great application potential and value in many fields such as oil and gas, chemical processing, seawater desalination, shipbuilding, and marine engineering with their excellent corrosion resistance, high strength, and good toughness. With the global emphasis on environmental protection and sustainable development, the demand for high-performance materials is growing, and ASTMA790 stainless steel pipes will undoubtedly play a more important role in future industrial development. For engineers and designers, an in-depth understanding and mastery of the technical characteristics and application points of this material will help them make more reasonable and economical choices in project design and promote the progress and development of industrial technology.