Beckton Desalination Plant
Courtesy of Millstock Stainless
Fasteners for Pumps and Valves
Courtesy of West Special Fasteners
2205 Duplex is a generic term for the most common of the duplex stainless steels. It has become the grade of choice where 316/316L does not have adequate corrosion resistance.
Approximate Composition – 22% Cr 5% Ni 3% Mo 0.15% N (exact composition ranges vary between EN and ASTM standards).
This grade combines the following characteristics:
• Design strength 2 times that of standard austenitic grades
• Excellent pitting and crevice corrosion resistance
• Excellent resistance to stress corrosion cracking
• Good weldability
• Moderate impact toughness down to minus 80°C
Many chemical and marine processes operate in very aggressive conditions. These push the more familiar grades such as 316/316L (1.4401/1.4404) beyond their limits. 2205 Duplex (1.4462) provides a significant improvement in corrosion resistance. The increased strength can also lead to a reduction in section thickness which means that the overall cost can be comparable to that of 316/316L. Resistance to stress corrosion cracking is particularly important in chemical and food processing above 50°C. Although weldability is good, fabricators need to be trained in the specific parameters required to produce sound welds.
Typical applications include:
Offshore oil and gas, chemical processing, desalination plant, pulp and paper, sculptures in coastal locations, brewing, food processing, bridges, tensioning systems, nuclear reprocessing, tunnel infrastructure, chemical tanker ships.
2205 Duplex (1.4462) is the natural choice for more aggressive environments.