Duplex Stainless Steel

Duplex stainless steels are two-phase alloys based on the Fe-Cr-Ni system. The specific advantages offered by duplex stainless steels over conventional 300 series stainless steels are strength (approximately twice that of austenitic stainless steels), improved toughness and ductility (compared to ferritic grades), and a superior chloride SCC resistance and pitting resistance. The high yield strength offers weight reduction with improved lead bearing capacity.

There are four main types of duplex steel in the market categorised as lean duplex, standard duplex, super duplex and hyper duplex which are differentiated by chemical analysis, mechanical and corrosion properties. The similarity is that they all have a ferritic solidification and their austenitic formation is finalized at approximately 800 deg C. The ferrite property gives strength and resistance to stress corrosion cracking and the austenitic gives the ductility and general corrosion resistance.

The development of lean duplex was attributed due to the increasing cost of alloying elements and nickel. The steel producers achieved a chemical composition that gave the same high strength and a bit reduced corrosion properties with a much lower level of nickel.

The popular grades of duplex that are offered by us from stock are -

• Standard duplex -
  • Grade 2205 - EN S31803 / S32205 - Werkstoff No. 1.4462
• Super duplex -
  • Grade 2507 - EN S32750 - Werkstoff No. 1.4410
  • Grade Zeron 100 - EN S32760 - Werkstoff No. 1.4501
  • Grade Ferrinox 255 - EN S32520 - Werkstoff No. 1.4507 or
  • Grade Uranus 2507Cu - EN S32550 - Werkstoff No. 1.4507
• Lean duplex -
  • Grade 2101 LDX - EN S32101 - Werkstoff No. 1.4162
  • Grade DX 2202 - EN S 32202 - Werkstoff No. 1.4062
  • Grade RDN 903 - EN S 32001 - Werkstoff No. 1.4482
  • Grade 2304 - EN S 32304 - Werkstoff No. 1.4362

Typical Applications -

• Chemical processing Plants and chemical transport and storage
• Marine environment
• Oil and Gas exploration and refining
• Offshore rigs
• Pulp and paper manufacturing
• Pollution control equipment
• Hot water boilers
• Brewing tanks
• Desalination plants

Product Forms:

• Sheets, Strips, Plates, Checkered Sheets
• Round Bars, Hexagon, Flat Bars - rolled and processed, Beams, Angles, Channels, Squares
• Pipes, Tubes, Square and rectangular hollow sections, Fittings and Flanges
• Wires
• Fasteners