Datasheet updated

2024-01-11 10:29
(supersedes all previous editions)

SAF™ 2205+ is a duplex (austenitic-ferritic) stainless steel with excellent material cleanliness, for highly demanding applications. The grade is characterized by:

  • Alignment to IOGP S-563 and ISO 17781 standards
  • Decreased phosphorous and sulfur content to match higher demanding applications
  • 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 and crevice corrosion
  • High mechanical strength – roughly twice the proof strength of austenitic stainless steels
  • Good hot-working properties
  • High resistance to erosion corrosion and corrosion fatigue
  • Physical properties that offer design advantages
  • Good weldability

Standards

  • UNS: S31803, S32205
  • EN Number: 1.4462
  • W.Nr.: 1.4462

Product standards

  • IOGP S-563:2018
  • ISO 17781:2017
  • EN 10088-3, EN 10088-5 (dimensions up to 160 mm), EN 10272, EN 10222-5,
  • ASTM A479, ASTM A276,
  • NORSOK MDS D47 Rev 3, Rev 4, Rev 5 
  • Chemical composition and mechanical properties acc. to ASTM A182

Approvals

  • Pressure Equipment Directive (PED 2014/68/EU)
  • NORSOK M650 Ed. 4, NORSOK M630 Ed. 6, dimensions up to 260 mm.
  • DNV, dimensions up to 300 mm
  • Pre-approval for PMA

Certificate

  • Status according to EN 10204/3.1

Chemical composition (nominal)

Chemical composition (nominal) %
C Si Mn P S Cr Ni Mo N
≤0.030 ≤1.0 ≤2.0 ≤0.020 ≤0.010 22.5 5.5 3.2 0.18

Applications

Due to its excellent corrosion properties, SAF™ 2205+ is a highly suitable material for service in environments containing chlorides and hydrogen sulfide. The material is suitable for use in flowlines for the extraction of oil and gas from sour wells, in refineries and in-process solutions contaminated with chlorides. SAF™ 2205+ is particularly suitable for chloride-bearing water or brackish water is used as a cooling medium. The steel is also suitable for use in dilute sulphuric acid solutions and for the handling of organic acids, e.g. acetic acid and mixtures.

  • The high strength of SAF™ 2205+ makes the material an attractive alternative to austenitic steels in structures subject to heavy loads.
  • The good mechanical and corrosion properties make SAF™ 2205+ an economical choice in many applications by reducing the life cycle cost of the equipment.

Corrosion resistance

General corrosion

In most media, SAF™ 2205+ possesses better resistance to general corrosion than steel of type ASTM 316L and ASTM 317L. Impurities that increase corrosivity are often present in process solutions of acids. If there is a risk of active corrosion, higher-alloyed austenitic stainless steels should be chosen, e.g. Alleima® 2RK65 or Sanicro® 28.

Stress corrosion cracking

The standard austenitic steels of the ASTM 304L and ASTM 316L types are prone to stress corrosion cracking (SCC) in chloride-bearing solutions at temperatures above 60°C (140°F). Duplex stainless steels are far less prone to this type of corrosion. Laboratory tests have shown good resistance to stress corrosion cracking of SAF™ 2205+. Results from these tests are presented in fig. 3. The diagram indicates the temperature-chloride range within which SAF™ 2205+, the standard steels ASTM 304L and ASTM 316L can be used without risk of stress corrosion cracking.


Sandvik SAF 2205+_7397b rev 1.jpg

Forms of supply

  • Bar
  • Finishes and dimensions:
    Bar steel in grade SAF™ 2205+ is stocked in a number of sizes. The standard size range for stock comprises 75-260mm (selected dimensions). Round bar is supplied in the solution annealed and quenched and peel-turned condition.
  • Lengths
    Bars are delivered in random lengths of 3-7 m, depending on diameter.

Straightness

75 – 260mm 1 mm/m

Tolerances

Diameter, mm Tolerances, mm
75-260 -0/+1.50

Surface condition

Ra, µm, typical values Diameter, mm
Peeled and burnished 1 75-200
Peel turned 2 >205 - 260

Heat treatment

SAF™ 2205+ stock program bars are delivered in the solution annealed and quenched condition.

Solution annealing

Solution annealing at 1020 – 1100°C (1870 – 2010°F) followed by quenching.

Mechanical properties

The following values apply to material in the solution annealed and quenched condition up to bar stock size 260mm.

At 20°C (68°F)

Metric units

Proof strength Tensile strength Elong. Hardness
Rp0.2a) Rp1.0a) Ab) Brinell
MPa MPa MPa %
≥450 ≥500 660-860 ≥25 ≤270
Imperial units
Proof strength Tensile strength Elong. Hardness
Rp0.2a) Rp1.0a) Ab) Brinell
ksi ksi ksi %
≥65 ≥73 96-125 ≥25 ≤270

1 MPa = 1 N/mm 2
a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength respectively.
b) Based on L0 = 5.65√S, where L0 is the original gauge length and S0 the original cross-sectional area.

Sandvik SAF 2205+_7396b rev 1.jpg

Impact strength

SAF™ 2205+ possesses good impact strength both at room temperature and at low temperatures. Fig. 2 shows typical impact energy values for SAF™ 2205+ bars in different sizes at -50°C (-58°F). The values apply for standard Charpy-V specimens (10 x 10 mm, 0.39 x 0.39 in.) taken in the longitudinal direction of the bar. For dimensions larger than 260 mm (10.2 in.) the impact strength is somewhat lower.

SAF™ 2205+ bar stock program guarantees an impact strength of 70 J (52 ft-lb) at -50°C (-58°F) for dimensions up to 260 mm (10.2 in.). Over 260 mm (10.2 in.), values for information only.

Figure 2. Typical impact strength values for Sandvik SAF 2205™+ bar at -50°C (-58°F).

At high temperatures

If SAF™ 2205+ is exposed for prolonged periods to temperatures exceeding 280 °C (540 °F), the microstructure changes which results in a reduction in impact strength. This effect does not necessarily affect the behavior of the material at the operating temperature. Contact Alleima for advice. For pressure vessel applications, 280°C (540°F) is required as a maximum.

Temp. Proof Strength Temp. Proof Strength
Rp0.2 Rp0.2
°C MPa °F ksi
min. min.
100 360 200 52
150 335 300 49
200 315 400 46
250 300 500 44

Physical properties

Density: 7.8 g/cm3, 0.28 lb/in3

Specific heat capacity
Temperature, °C J/(kg °C) Temperature, °F Btu/(lb °F)
20 480 68 0.11
100 500 200 0.12
200 530 400 0.13
300 550 600 0.13
400 590 800 0.14

Thermal conductivity

Metric units

Temperature,°C 20 100 200 300 400
W/(m °C)
SAF™ 2205+ 14 16 17 19 20
ASTM 316L 14 15 17 18 20

Imperial units

Temperature, °F 68 200 400 600 800
Btu/(ft h °F)
SAF™ 2205+ 8 9 10 11 12
ASTM 316L 8 9 10 10 12

Thermal expansion, mean values in temperature ranges (x10-6)

Metric units
Temperature, °C 30-100 30-200 30-300 30-400
Per °C
SAF™ 2205+ 13.0 13.5 14.0 14.5
Carbon steel 12.5 13.0 13.5 14.0
ASTM 316L 16.5 17.0 17.5 18.0
Imperial units
Temperature, °F 86-200 86-400 86-600 86-800
Per °F
SAF™ 2205+ 7.0 7.5 7.8 8.0
Carbon steel 6.8 7.0 7.5 7.8
ASTM 316L 9.0 9.5 9.8 10.0

Sandvik SAF 2205+_7393b-rev 1.jpg

Resistivity
Temperature, °C μΩm Temperature, °F μΩin.
20 0.74 68 29.1
100 0.85 200 33.1
200 0.96 400 39.8
300 1.00 600 43.3
400 1.10 800 43.3
Modulus of elasticity ( x103 )
Temperature, °C MPa Temperature, °F ksi
20 200 68 29.0
100 194 200 28.2
200 186 400 27.0
300 180 600 26.2

Welding

The weldability of SAF™ 2205+ is good. Welding must be carried out without preheating. Subsequent heat treatment is normally not required. Suitable methods of fusion welding are manual metal-arc welding (MMA/SMAW) and gas-shielded arc welding, with the TIG/GTAW method as first choice.

For SAF™ 2205+ heat-input of <2.5 kJ/mm and interpass temperature of <150°C (300°F) are recommended.

Recommended filler metals:

TIG/GTAW or MIG/GMAW welding

ISO 14343-A W/G 22 9 3 N L / AWS A5.9 ER2209 (e.g. Exaton 22.8.3.L)

MMA/SMAW welding

ISO 3581-A E 22 9 3 N L R / AWS A5.4 E2209-17 (e.g. Exaton 22.9.3.LR)

For welds exposed to particularly severe environments more resistant welding consumables are recommended:

TIG/GTAW or MIG/GMAW welding

ISO 14343-A W/G 25 9 4 N L / AWS A5.9 ER2594 (e.g. Exaton 25.10.4.L)

MMA/SMAW welding

ISO 3581-A E 25 9 4 N L R / AWS A5.4 E2594-16 (e.g. Exaton 25.10.4.LR)

Machining

The machining of SAF™ 2205+, as with other stainless steels, requires an adjustment of tooling data and machining method in order to achieve satisfactory results. Compared to Sanmac® 2205, the cutting speed must be reduced when turning SAF™ 2205+ with coated cemented carbide tools. The same applies to most other cutting operations. Feed should only be modified slightly and with caution.

The table below shows the ranges within which you can choose cutting data to obtain a tool life of 7 minutes in the duplex material SAF™ 2205+. The diagram is applicable for short cutting times. For long, continuous cuts, the cutting speeds should be slightly reduced.

Recommended insert and cutting data for turning SAF™ 2205+

Insert Cutting data Application
Geometry Grade Insert Feed Cutting speed
mm/rev. in./rev. m/min ft/min
MF
GC2015
SNMG 120404-MF
0.15
0.006
180
590
Finishing
MM
GC2025
SNMG 120408-MM
0.25
0.010
100
330
Medium machining

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.