What is Duplex Stainless Steel?
Duplex Stainless Steel is a type of steel containing the high amount of chromium and minimum amount of nickel. It provides great strength and resistance to corrosive environments. It is used in desalination plants, heat exchangers, and marine processes.
This stainless steel alloy offers good resistance to localized as well as to uniform corrosion. The duplex microstructure of the alloy contributes to the high strength and high resistance to stress corrosion cracking. It has good weld ability and offers many beneficial properties of ferritic and austenitic steels combined.
Duplex Stainless Steel gives very good resistance to pitting and crevice corrosion and has high resistance to stress corrosion cracking and corrosion fatigue. It displays high mechanical strength and also provides good abrasion and erosion resistance. It is used in chemical, Oil and gas and marine industries. Other uses if the duplex stainless steel is in pollution control equipments, pulp & paper manufacturing, seawater desalination plants and in flue-gas cleaning to name a few.
Typical Properties:
- Low cost
- Alternative to high nickel based alloys
- High strength
- Corrosion resistant
- Very hard machining
Specification:
- ASTM A789/SA789 - Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service
- ASTM A790/SA790 - Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
- ASTM A928 - Standard Specification for Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric Fusion Welded with Addition of Filler Metal
Note: For sizes other than given, please check with our office for further confirmation.
Duplex stainless steel
| Steel No. | Standard No. | Type | Chemical composition | Other | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | S | P | Mn | Cr | Ni | Mo | Other | ób | ós | δ5 | HB | ||||
| 0Cr26Ni5Mo2 | GB1220 | Bar | 0.08 | 1 | 0.03 | 0.035 | 1.5 | 23-28 | 3-6 | 1-3 | 590 | 390 | 18 | 277 | ψ%:40 | |
| 0Cr26Ni5Mo2 | GB4237 | Plate | 0.08 | 1 | 0.03 | 0.035 | 1.5 | 23-28 | 3-6 | 1-3 | 590 | 390 | 18 | 277 | ||
| 0Cr26Ni5Mo2 | GB/T14976 | Pipe | 0.08 | 1 | 0.03 | 0.035 | 1.5 | 23-28 | 3-6 | 1-3 | 590 | 390 | 18 | |||
| 00Cr18Ni5Mo3Si2 | GB1220 | Bar | 0.03 | 1.3-2 | 0.03 | 0.035 | 1.2-1.6 | 18-19.5 | 4.5-5.5 | 2.5-3 | 590 | 390 | 20 | ψ%:40 | ||
| 00Cr18Ni5Mo3Si2 | GB4237 | Plate | 0.03 | 1.3-2 | 0.03 | 0.03 | 1.2-1.6 | 18-19.5 | 4.5-5.5 | 2.5-3 | N:0.1 | 590 | 390 | 20 | ||
| HDR | Q/SJB11-99 | Pipe | 0.03 | 1 | 0.03 | 0.035 | 2 | 23-26 | 4.5-7.5 | 2-3 | 650 | 450 | 27 | |||
Duplex stainless steels possess a mixed microstructure of ferrite and austenite. They contain a high chromium content of 22 wt.% – 25 wt.%, a molybdenum content of up to 5 wt.% and a low nickel content.
Duplex stainless steels exhibit roughly twice the strength of austenitic stainless steels and possess greater resistance to chloride stress corrosion cracking compared to austenitic stainless steels, albeit less so than ferritic. They exhibit toughness between that of ferritic and austenitic.
Examples & applications of duplex stainless steels
Due to these properties, duplex stainless steels are ideal for demanding environments where good mechanical properties are required in addition to good corrosion resistance. Common examples of duplex stainless steels include:
- 2205, used in chemical processing, oil and gas processing equipment, marine and other high chloride environments, effluent scrubbing systems, pulp and paper industry, cargo tanks for ships and trucks, food processing equipment, biofuels plant.
- 2304, used in chloride containing environments, welded pipe systems, transportation, heat exchanger tubes, construction, pressure vessels, caustic solutions and the food industry.
- 2507, used in oil and gas industry equipment, offshore platforms, chemical process industries, desalination plants, mechanical and structural components and power industry FGD systems.
Delivery requirment:
Inspection
Packed in bundles
Finished tubes
Packing in wooden case- Marking: SunnySteel, material grade, standard, specification, heat no.
- Surface Treatment: Bright annealed, polished outside and inside surface.
- Package: Each pipe in a PVC bag and caps on both ends then bundled in wood case,
- Option: Bundle with knitted plastic bag/stee crate.
- Mill test certificate: according to EN 10204 3.2
- Inspection: Third party inspection, or by clints
