2205 Duplex

2205 duplex stainless steel contains 22% chromium, 5% nickel, 3.2% molybdenum and other alloying elements such as nitrogen and manganese, the high chromium, molybdenum and nitrogen contents provide corrosion resistance superior to 316/316L and 317L stainless, it is Austenitic-Ferritic phase structure grade.

  • High yield strength – roughly twice of Austenitic stainless steel
  • Most widely used duplex stainless steel grade, around 60%
  • Outstanding resistance to stress corrosion cracking, crevice, pitting, erosion, and general corrosion in severe environments
  • 2205 is not suggested for operating temperatures above 300°C and below -50°C
  • The high strength of 2205 results in its machinability slower, like cutting, forming, bending
  • Good weldability
  • 2205 is not the same with S31803, but very close, in many instances, it is alternative

2205 Duplex Chemical Composition (% Max)

CMnSiPSCrMoNiN
2205
(S31803)
0.032.01.00.030.0221.0 – 23.02.5 – 3.54.5 – 6.50.08 – 0.20
2205
(S32205)
0.032.01.00.030.0222.0 – 23.03.0 – 3.54.5 – 6.50.14 – 0.20

2205 Duplex Mechanical Properties

Tensile Strength (Mpa) MinYield Strength (Mpa) MinElongation (%)Hardness (HRC) Max
2205 (S31803)6204502530
2205 (S32205)6554852530

2205 Duplex Equivalent Grades

AISIUNSDINENJISGB
2205S31803/S322051.4462X2CrNiMoN 22-5-3SUS 329J3L00Cr23Ni5Mo3N

2205 Stainless Steel Physical Properties

Density Melting Point Specific heat Thermal conductivity [W/(m·K)] Coefficient of Expansion( 10-6/K ) Electrical Resistivity Elastic modulus Magnetic
g/cm3 (℃) [J/(kg·K)] 0~100 ℃ 100 ℃ 500 ℃ 0~100 ℃ 0~500 ℃ ( NΩ.m kN/mm2
7.80 1398~1427 450 16.3 21.5 13.7 14..7 850 200 a little after cold worked

Corrosion Resistance

  • High resistance to stress corrosion cracking (SCC) in chloride-bearing environments
  • High resistance to stress corrosion cracking (SCC) in environments containing hydrogen sulphide
  • High resistance to general corrosion, pitting corrosion, and crevice corrosion
  • High resistance to erosion corrosion and corrosion fatigue

Heat Treatment

Duplex 2205 stainless steel heat treatment temperature range is 1020 to 1100°C, and cool rapidly。 2205 grade cannot be hardened by thermal treatment, but does work harden。

Typical Applications

Chemical processing, transport and storage, Oil and gas exploration and processing equipment, Marine and other high chloride environments, Pulp & Paper digesters, liquor tanks and paper machines.

2205 Duplex Specifications

  • ASTM A789, ASME SA789 – Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service
  • ASTM A790, ASME SA790 – General Requirements for alloy and Stainless Steel Pipe

2205 Duplex Forms

  • Tube
  • Pipe
  • Fitting