ASTM A789 Duplex 2205 Seamless Steel Tube For Marine Industry

SMLSCO implements strict quality control procedures for high-performance materials such as 2205 duplex steel to ensure performance meets standards. We use 100% PMI for material identification to prevent mixing. Each tube undergoes hydrostatic testing or non-destructive testing to ensure pressure bearing capacity. We conduct precise inspections on dimensional tolerances and surface quality, and can provide metallographic analysis, mechanical performance testing, etc. according to customer requirements to ensure every batch complies with ASTM A789 standards.

The unique feature of duplex stainless steel is its metallographic structure composed of approximately 50% austenite and 50% ferrite. This dual phase structure combines the advantages of both types of stainless steel: the good toughness and weldability of austenitic stainless steel, and the high strength and excellent stress corrosion cracking (SCC) resistance of ferritic stainless steel. This enables duplex steel to provide more reliable and economical solutions than conventional austenitic stainless steel in harsh corrosive environments.

2205 is currently the most widely used duplex stainless steel grade. Its yield strength is more than twice that of conventional austenitic stainless steels such as 316L, allowing thinner wall thickness designs in pressure applications, effectively reducing structural weight and saving costs. Its high chromium (Cr), molybdenum (Mo), and nitrogen (N) content provides extremely strong resistance to pitting corrosion and crevice corrosion (PREN ≥ 35). It is particularly resistant to stress corrosion cracking (SCC) in chloride containing environments, solving a major problem for traditional stainless steel in marine environments.

2205 duplex steel pipe is an ideal choice for the marine industry. Its excellent resistance to seawater corrosion and high-strength characteristics make it widely used in various key systems including process pipelines, seawater cooling systems, fire water systems, ballast water systems of offshore oil platforms, as well as structural components and pipelines on ships and chemical transport vessels. In seawater desalination (RO) equipment, it serves as the core material of high-pressure pipelines and heat exchangers, ensuring long-term, stable, and safe operation in harsh marine environments.