Duplex 2205 VS Super Duplex 2507 stainless steel flange

Duplex 2205 and Super Duplex 2507 stainless steel flanges are characterized by their high yield strength, which is twice that of the annealed yield strength of typical austenitic stainless steels, like 304 and 316 stainless steel flanges. Because of this, Duplex 2205 and Super Duplex 2507 steel are some of the most common grades of duplex used for flanges with Super Duplex 2507 flanges being the more corrosion resistant grade of the two.

Duplex 2205 and Super Duplex 2507 Stainless Steel Flange: A Comparison

When it comes to stainless steel flanges, two popular options are Duplex 2205 and Super Duplex 2507. These duplex stainless steels offer excellent corrosion resistance, high strength, and durability. In this section, we will compare the two grades, discuss their chemistry and specifications, and provide a mechanical data table for reference.

Duplex Flange Grades: Duplex 2205 vs. Super Duplex 2507

Duplex 2205 Stainless Steel Flange

Duplex 2205 is a duplex stainless steel that consists of a balanced mixture of austenite and ferrite phases. It offers a combination of high strength and excellent corrosion resistance, making it suitable for various applications. Some key features of Duplex 2205 stainless steel flange include:

Chemical Composition: Duplex 2205 contains approximately 22% chromium, 5-6% nickel, 3-3.5% molybdenum, and small amounts of other elements such as nitrogen and manganese. This composition contributes to its corrosion resistance and mechanical properties.
Corrosion Resistance: Duplex 2205 exhibits good resistance to localized corrosion, including pitting and crevice corrosion. It also offers resistance to general corrosion in many environments, such as those containing acids, alkalis, and chloride ions.
Strength and Toughness: Duplex 2205 has high tensile and yield strength, providing it with excellent mechanical properties. It also demonstrates good toughness, allowing it to withstand impact and heavy loads.

Super Duplex 2507 Stainless Steel Flange

Super Duplex 2507 is a higher alloyed version of duplex stainless steel, offering enhanced corrosion resistance and superior strength compared to Duplex 2205. Some key features of Super Duplex 2507 stainless steel flange include:

Chemical Composition: Super Duplex 2507 contains approximately 25% chromium, 7% nickel, 4% molybdenum, and small amounts of other elements such as nitrogen and copper. This composition provides it with exceptional corrosion resistance and mechanical properties.
Corrosion Resistance: Super Duplex 2507 exhibits excellent resistance to a wide range of corrosive environments, including those containing chlorides, acids, and seawater. It offers superior resistance to pitting, crevice corrosion, and stress corrosion cracking.
Strength and Durability: Super Duplex 2507 has higher tensile and yield strength compared to Duplex 2205, making it suitable for demanding applications that require robust and reliable components. It also demonstrates good ductility and impact toughness.

Chemistry & Specifications

Here is a comparison of the chemistry and specifications of Duplex 2205 and Super Duplex 2507 stainless steel flanges:

Property	Duplex 2205 Stainless Steel Flange	Super Duplex 2507 Stainless Steel Flange
Chromium (Cr)	21-23%	24-26%
Nickel (Ni)	4.5-6.5%	6-8%
Molybdenum (Mo)	2.5-3.5%	3-5%
Nitrogen (N)	0.08-0.2%	0.24-0.32%
Copper (Cu)	–	0.5-1.0%
Tensile Strength	620-900 MPa	750-1000 MPa
Yield Strength	450-650 MPa	550-800 MPa
Elongation	>25%	>25%
Hardness (Brinell)	293 max	270 max
ASTM Specifications	A182 F51, A240, A276, A479	A182 F53, A240, A276, A479