- VIRAMISTEELMARKETING@GMAIL.COM
Virami Steel Hub
What is ASTM A182 / UNS S31803 (2205) Duplex
ASTM A182 / UNS S31803 (2205) DUPLEX is a high-performance stainless steel alloy exhibiting excellent properties from the combination of both austenitic and ferritic stainless steels, also known as 2205 Duplex Stainless Steel. This material offers superior strength, corrosion resistance, and stress corrosion cracking resistance over conventional stainless steel grades and, therefore, widely accepted in aggressive environments. It belongs to the class of alloy known as 2205 Duplex Stainless Steel ASTM A182 / UNS S31803. Its particular double phase microstructure with close to equal content of both austenite and ferrite gives this material an excellent combination of strength, toughness, and corrosion resistance.
It is specifically designed for better performance in aggressive environments such as chloride exposure and high stress. Enhanced resistance to pitting, crevice corrosion, and stress corrosion cracking has placed 2205 surfacing over the years as the material of choice in oil and gas applications, chemical processing, marine use, and pulp and paper manufacturing.
The alloy is relatively inexpensive but exhibits resistance to extreme conditions: it is typically used for those components such as heat exchangers, pressure vessels, pipelines, and seawater systems. Its excellent weld ability and very long-term durability further increase its versatility and value.
Definition of ASTM A182 / UNS S31803 (2205) DUPLEX
The high-performance stainless steel alloy 2205 Duplex Stainless Steel, commonly known as ASTM A182 / UNS S31803, has a balanced dual-phase microstructure and comprises roughly 50% ferrite and 50% austenite. Superior mechanical strength, resistance to corrosion, and resistance to stress corrosion cracking in difficult conditions would all be guaranteed by such a special composition.
With a composition of 21-23% chromium, 4.5-6.5% nickel, 2.5-3.5% molybdenum, and 0.08-0.2% nitrogen, this alloy is highly resistant to pitting, crevice corrosion, and cracking caused by stress corrosion caused by chloride. Structures can be made lighter and thinner without sacrificing strength since it has a better yield strength than austenitic stainless steels 304 and 316.
Welding Properties of ASTM A182 / UNS S31803 (2205) Duplex
Good weld ability results for the ASTM A182/UNS S31803 (2205 Duplex Stainless Steel); however, keeping its two-phase microstructure in balance between ferrite and austenite is essential. Proper technique applied to welding and proper parameters will be critical because improper technique may adversely affect the mechanical properties of the material itself and its corrosion resistance.
Key Welding Characteristics:
Preheating and Post-Weld Treatment.
2205 Duplex stainless steel does not usually call for preheating.
In critical applications, post-weld heat treatment may be advisable to restore ferrite-austenite balance and relieve residual stresses.
Heat Input:
Controlled input of the heat is also essential since high ferrite formation causes brittleness and excessive austenite produces the low corrosion resistance. Low to moderate heat input is preferred.
Interpass Temperature: This is to avoid raising the microstructure of the material up to 150°C, or 300°F.
Filler Material:
The filler materials are matched or slightly over-alloyed and include ER2209 or E2209, to retain a balanced microstructure in the weld zone.
Shielding Gas:
In GTAW and GMAW, an inert gas such as argon enriched with a small amount of nitrogen is used for the purpose of aiding in the formation of more austenite in the HAZ.
Corrosion Resistance of Weld Areas.
Intermetallic phases such as the sigma phase are formed in improperly welded specimens, which can compromise corrosion resistance.
After welding, rapid cooling is important to avoid the precipitation of carbide or nitride. Residual Stress Control: Residual stresses are predominant in duplex stainless steel, and thus it requires proper handling and stress-relief techniques, especially for thick sections.
Chemical composition
| Cr | Ni | Mo | C | N | Mn | Si | P | S | Fe |
|---|---|---|---|---|---|---|---|---|---|
| 22.0-23.0 | 4.50-6.50 | 3.00-3.50 | .030 Max | 0.14-0.20 | 2.00 Max | 1.00 Max | .030 Max | .020 Max | Balance |
Conclusion of ASTM A182 / UNS S31803 (2205) Duplex
A182/UNS S31803 Duplex Stainless Steel, 2205-in is a high-performance material that combines ferritic strength with the corrosion protection of austenitic steels. Accordingly, its microstructure is found in dual-phase configuration, giving it an extraordinary property balance for every application.
However, with superior resistance to pitting, crevice corrosion, and stress corrosion cracking combined with high yield strength and excellent durability, 2205 Duplex is a cost-effective solution for the oil and gas, chemical processing, marine engineering, and pulp and paper manufacturing industries.