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Duplex Alloy: 2003

Penn Stainless offers Duplex 2003 in the following tubular forms:

  • Welded Duplex Alloy 2003 Pipe
  • Welded Duplex Alloy 2003 Tube
  • Seamless Duplex Alloy 2003 Pipe
  • Seamless Duplex Alloy 2003 Tube

Please click on each of the below tabs to review different sections of the data sheet.

General Properties

ATI 2003 (UNS S32003) lean duplex stainless steel (LDSS) is a molybdenum-enhance, duplex stainless steel alloy. Cr, Ni, Mo, and N are controlled to balance costs. This grade falls between Type 316 and the 2205 alloy in terms of corrosion resistance, while posessing the higher mechanical properties characteristic of a duplex stainless steel.

Sample Applications

  • Pressure vessels
  • Chemical processing
  • Heat exchangers
  • Home appliances



A240 (plate, sheet and strip), A270 (sanitary tube), A480, A789 (tube),
A790 (pipe), and A928 (pipe welded with filler).


  • ATI 2003 LDSS is resistant to dilute reducing acids and moderate concentrations of oxidizing acids. The alloy is also resistant to low concentrations of organic acids. Corrosion rates in several solutions are shown in the Table below.
  • The nickel-free ferritic steels are essentially immune to chloride stress corrosion cracking.
  • No cracking or pitting was observed on any of the as-welded or base metal samples of ATI 2003 material that were tested.


  • ATI 2003 LDSS can be welded by most methods used to weld stainless steels. Autogenous welding will increase the amount of ferrite present in the weldment and adjacent areas of the base metal. Subsequent annealing will tend to restore the balance of phases in the base metal. A nitrogen addition is recommended with autogenous welding to preserve corrosion resistance and
  • Commercially available overmatched filler metals are suggested for welding ATI 2003 LDSS

Heat Treatment

  • ATI 2003 molybdenum-enhanced lean duplex stainless steel should be annealed between 1850 and 2010°F (1010-1100°C) and
    cooled quickly. Annealing near 2010°F (1100°C) will increase the amount of ferrite present in the microstructure compared to that
    resulting from annealing near 1850°F (1010°C). Cold-bent sections in excess of 10% deformation should be fully annealed after
    forming. Stress relief heat treatments in the 750 to 1650°F (400-900°C) range adversely affect the properties of the alloy and should
    not be considered.

Chemical Properties:

Element Weight Percent
Carbon 0.030 max
Manganese 2.00 max
Phosphorous 0.030 max
Sulfur 0.020 max
Silicon 1.00 max
Chromium 19.50-22.50
Nickel 3.00-4.00
Molybdenum 1.50-2.00
Nitrogen 0.14-0.20
Iron Balance

Mechanical Properties:

Grade Tensile Strength (ksi) min Yield Strength 0.2% offset (ksi) min Elongation (% in 50mm) min




Physical Properties:


0.280 lb/in^3 (7.78 g/cm^3)

Magnetic Permeability


Specific Heat 73-212°F (23-200 °C)

.12 BTU/lb-°F (0.51 kJ/kg-K)

 Thermal Conductivity 73-212°F (23-100°C)  10 BTU-ft/hr-ft^2-°F (17 W/m-K)
Elastic Modulus 3 x 10^6 psi (210 GPa)

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