2205 DSS

Material

S31803, S32205, 1.4462, X2CrNiMoN22-5-3, 022Cr22Ni5Mo3N, 022Cr23Ni5Mo3N

Overview

2205 duplex stainless steel (2205 DSS) is a two-phase, ferritic-austenitic 22% chromium, 5 to 6% nickel, 3% molybdenum alloyed stainless steel. It contains about 40~50% ferrite in the annealed condition. 2205 has been a practical solution to chloride stress corrosion cracking problems experienced with 304/304L or 316/316L stainless. The high chromium, molybdenum and nitrogen contents provide corrosion resistance superior to 316/316L and 317L stainless in most environments. The design strength of 2205 is significantly higher than 316/316L, often permitting lighter wall construction.

Characteristics

Duplex stainless steel is characterized by good fatigue strength, as well as outstanding intercrystalline corrosion resistance, stress corrosion resistance, pitting corrosion resistance, low coefficient of thermal expansion and work temperature up to 200-250 ℃. Compared to ordinary austenitic acid resistant steels, it exhibits much better strength properties and higher wear resistance and erosion resistance.

Application

DSS resists chloride environments and sulphide stress corrosion and is roughly double the strength of standard austenitic stainless steels. It can be used successfully as an alternative to 300 series austenitic stainless steel in most applications where higher mechanical strength/lower weight is required.
Typical applications include pipework with various applications in the oil-gas, chemical, shipbuilding, aviation, cryogenic, paper, mining, petrochemical, power, Pharmaceutical and Biotechnology industries.

Chemical composition

Material C Si Mn P S
S31803 ≤0.03 ≤1.0 ≤2.0 ≤0.030 ≤0.020
S32205 ≤0.03 ≤1.0 ≤2.0 ≤0.030 ≤0.020
Material Cr Ni Mo N
S31803 21.0~23.0 4.50~6.50 2.50~3.50 0.08~0.20
S32205 22.0~23.0 4.50~6.50 3.00~3.50 0.14~0.20

Corrosion resistance

Compared to conventional austenitic stainless steels such as Type 304 and 316, 2205 DSS possesses superior resistance in most oxidizing and reducing acids; superior chloride pitting and crevice corrosion resistance due to higher chromium, molybdenum and nitrogen content; and superior resistance to chloride stress corrosion cracking.

Mechanical property

  • ◎Tensile Strength: 90 KSI min (620 MPa min)
  • ◎Yield Strength(0.2% Offset): 65 KSI min(450 MPa min)
  • ◎Elongation: 25% min.
  • ◎Reduction of area: 45% min

Heat treatment

  • ◎Temperature: 1870~2010°F (1020~1100°C)
  • ◎Rapid cooling in air or water
  • ◎Hardness: HRC30, HBW290, HV290 max.
  • ◎Hardening: It cannot be hardened by heat treatment. Can be hardened only by cold working.

Available process

  • ◎ Hot worked
  • ◎ Cold worked
  • ◎ Cold worked and bright annealed
  • ◎ Cold worked, annealed and pickled
  • ◎ Cold worked, polished (MP, EP etc.)
  • ◎ Cold worked, bright annealed, polished (MP, EP etc.)

Common tests

  • ◎ Chemical composition
  • ◎ Tension
  • ◎ Hardness
  • ◎ Flaring
  • ◎ Flange
  • ◎ Flattening
  • ◎ Micro structure
  • ◎ Hydrostatic
  • ◎ NDT
  • ◎ Intergranular Corrosion
  • ◎ Surface condition
  • ◎ Shape and dimension
  • ◎ Positive Material Identification

Product forms

Capillary tube

  • ◎ OD 0.08 ~ 6.0 mm
  • ◎ WT 0.015 ~ 1.5 mm

Micro ID and heavy wall seamless tube

  • ◎ OD 3.0 ~ 50.0 mm
  • ◎ ID 0.30 ~ 5.0 mm

Precision seamless tube

  • ◎ OD 6.0 ~ 89 mm
  • ◎ WT 0.50 ~ 9.0 mm

Precision Conic Seamless Tube

  • ◎ OD 6.0 ~ 89 mm
  • ◎ WT 0.50 ~ 9.0 mm

HP / UHP BA+ tube

  • ◎ OD 1.0 ~ 76 mm
  • ◎ WT 0.10 ~ 10.0 mm

Service

  • ◎ Precision cutting
  • ◎ Tube surface treatment, like ID surface super mirror polishing, best level could reach Ra0.0015um
  • ◎ Tube deep processing, like coiling, bending, end forming, body forming, laser processing, various needles processing, built to drawing and sample, etc.