Mechanical Property | Value |
|---|
| Proof Stress | 450 Min MPa |
| Tensile Strength | 620 Min MPa |
| Elongation | 25 Min % |
| Hardness Brinell | 290 Max HB |
Grade | Tensile Strength
ksi (min) | Yield Strength
0.2% ksi (min) | Elongation % | Hardness (HB) MAX |
2205 | 90 | 65 | 25 | 217 |
Chemical Composition of duplex 2205 stainless steel
Chemical Element | % Present |
|---|
| Carbon (C) | 0.0 - 0.03 |
| Chromium (Cr) | 21.00 - 23.00 |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 1.00 max |
| Phosphorous (P) | 0.0 - 0.03 |
| Sulphur (S) | 0.0 - 0.02 |
| Nickel (Ni) | 4.50 - 6.50 |
| Nitrogen (N) | 0.08 - 0.20 |
| Molybdenum (Mo) | 2.50 - 3.50 |
| Iron (Fe) | Balance |
Physical Property | Value |
|---|
| Density | 7.805 g/cm³ |
| Thermal Expansion | 13.7 x10^-6 /K |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity | 19.0 W/m.K |
| Electrical Resistivity | 0.085 x10^-6 Ω .m |
Alloy Designations of duplex 2205/1.4462 Stainless Steel
Grade 1.4462/2205 is similar to:
UNS S31803
UNS S32205
BS 318S13
Supplied Forms
- Fittings & Flanges
- Pipe
- Plate
- Sheet
- Tube
- Bar
Duplex 2205 stainless steels are typically used in:
- ~ Chemical processing, transport and storage
- ~ Generally where 304 and 316L are used
- ~ Oil and gas exploration and offshore rigs
- ~ Oil and gas refining
- ~ Pressure vessels (weight savings)
- ~ Marine environments
- ~ Pollution control equipment
- ~ Pulp and paper industry (chip storage tanks, white and black
liquor tanks, digestors)
- ~ Chemical process plant
- ~ Caustic solutions, organic acids (SCC resistance)
- ~ Mining (abrasion/corrosion)
- ~ Food industry
Corrosion Resistance
Duplex stainless steels are extremely corrosion resistant. They
have high resistance to intergranular corrosion. Even in chloride
and sulphide environments, duplex stainless steels exhibit very
high resistance to stress corrosion cracking.
The super duplex grades are even more resistant to corrosion.
Heat Resistance
The high chromium content of duplex stainless steels that protects
against corrosion, causes embrittlement at temperatures over about
300°C.
At low temperatures duplex stainless steels have better ductility
than the ferritic and martensitic grades. Duplex grades can readily
be used down to at least -50°C.
Fabrication
Fabrication of all stainless steels should be done only with tools
dedicated to stainless steel materials. Tooling and work surfaces
must be thoroughly cleaned before use. These precautions are
necessary to avoid cross contamination of stainless steel by easily
corroded metals that may discolour the surface of the fabricated
product.
Machinability
Although machinable, the high strengths of duplex stainless steels
makes machining difficult. As an example, machining of 2205 is
around 20% slower than for 304.
Machining can be enhanced by using the following rules:
~ Cutting edges must be kept sharp. Dull edges cause excess work
hardening.
~ Cuts should be light but deep enough to prevent work hardening by
riding on the surface of the material.
~ Chip breakers should be employed to assist in ensuring swarf
remains clear of the work
~ Low thermal conductivity of austenitic alloys results in heat
concentrating at the cutting edges. This means coolants and
lubricants are necessary and must be used in large quantities.
Heat Treatment
Duplex stainless steels cannot be hardened by heat treatment. They
can however be work hardened.
Solution treatment or annealing can be done by rapid cooling after
heating to around 1100°C.
Weldability
Duplex stainless steels have good weldability. All standard welding
processes can be used. They are not quite as easily welded as the
austenitic grades but low thermal expansion in duplex grades
reduces distortion and residual stresses after welding. The
recommended filler material for 2205 stainless steel is 2209.
