Duplex 2205 is a nitrogen enhanced duplex stainless steel that was developed to combat common corrosion problems encountered with the 300 series stainless steels. “Duplex” describes a family of stainless steels that are neither fully austenitic, like 304 stainless, nor purely ferritic, like 430 stainless. The structure of 2205 duplex stainless steel consists of austenite pools surrounded by a continuous ferrite phase. In the annealed condition, 2205 contains approximately 40-50% ferrite. Often referred to as the work horse grade, 2205 is the most widely used grade in the duplex family of stainless steels. The advantage of a duplex structure is that it combines the favorable qualities of a ferritic alloy (stress corrosion cracking resistance and high strength) with those of an austenitic alloy (ease of fabrication and corrosion resistance). Usage of 2205 Duplex stainless steel should be limited to temperatures below 600° F. Extended elevated temperature exposure can embrittle 2205 stainless.

Duplex 2205 Chemical Composition, %:

Cr	Ni	Mo	C	N	Mn	Si	P	S	Fe
22.0-23.0	4.50-6.50	3.00-3.50	0.03 max	0.14-0.20	2.00 max	1.00 max	0.03 max	0.02 max	Balance

Duplex 2205 ASTM Specification:

At Room Temperature, Investment Castings As Cast

Pipe Smls	Pipe Welded	Tube Smls	Tube Welded	Sheet / Plate	Bar	Fitting
A790	A790	A789	A789	A240	A276	A182

Mechanical Properties of Duplex 2205:

At Room Temperature, Investment Castings As Cast

Ultimate Tensile Strength	95 ksi minimum
Yield	(0.2 % offset) 65 ksi minimum

Ferralium 255 is a super duplex stainless steel supplied in the hot worked and annealed condition. It achieves higher strengths than most stainless steels and alternative corrosion resistant alloys, offering the potential to reduce section size and therefore weight and cost. As a 25% Cr alloy, with significant additions of copper, Ferralium® 255 offers excellent corrosion resistance in a wide variety of corrosive chemicals including sulphuric, nitric and phosphoric acid. In seawater and other chloride containing environments it also provides outstanding resistance to pitting and crevice corrosion, with Critical Pitting Temperature exceeding 50°C. Excellent ductility and impact strength at both ambient and sub-zero temperatures combine with a high resistance to abrasion, erosion and cavitation erosion.

Ferralium 255 Chemical Composition, %:

Cr	Ni	Mo	Cu	C	Mn	N	Si	P	S	Fe
24.5-26.5	5.5-6.5	3.1-3.8	1.5-2.0	0.025 max	0.8-1.2	0.20-0.25	0.70 max	0.025 max	0.005 max	Balance

Ferralium 255 ASTM Specification:

Pipe Smls	Pipe Welded	Tube Smls	Tube Welded	Sheet / Plate	Bar
A790	A790	A789	A789	A240	A479

Mechanical Properties of Ferralium 255:

Ultimate Tensile Strength	110 ksi or 760 Mpa minimum
Yield	(0.2 % offset) 80 ksi or 550 Mpa minimum
Elongation	15 %

Duplex 2507 is a super duplex stainless steel designed for applications which demand exceptional strength and corrosion resistance. Alloy 2507 has 25% chromium, 4% molybdenum, and 7% nickel. This high molybdenum, chromium and nitrogen content results in excellent resistance to chloride pitting and crevice corrosion attack and the duplex structure provides 2507 with exceptional resistance to chloride stress corrosion cracking. Usage of Duplex 2507 should be limited to applications below 600° F (316° C). Extended elevated temperature exposure can reduce both the toughness and corrosion resistance of alloy 2507. Duplex 2507 possesses excellent mechanical properties. Often a light gauge of 2507 material can be used to achieve the same design strength of a thicker nickel alloy. The resulting savings in weight can dramatically reduce the overall cost of fabrication.

Super Duplex 2507 Chemical Composition, %:

Cr	Ni	Mo	C	N	Mn	Si	Cu	P	S	Fe
24.0-26.0	6.0-8.0	3.0-5.0	0.03 max	0.24-0.32	1.20 max	0.80 max	0.50 max	0.035 max	0.02 max	Balance

Super Duplex 2507 ASTM Specification:

Pipe Smls	Pipe Welded	Tube Smls	Tube Welded	Sheet / Plate	Bar	Fitting
A790	A790	A789	A789	A240	A276	A182

Mechanical Properties of Super Duplex 2507:

Ultimate Tensile Strength	116 ksi minimum
Yield	(0.2 % offset) 80 ksi minimum
Elongation	15 %

Super Duplex Stainless Steel F55 is a highly alloyed stainless steel designed for use in aggressive environments. High strength, toughness, excellent corrosion resistance and its resistance to corrosion in a wide range of organic and inorganic acids are just a few characteristics that make this duplex stainless steel attractive to a variety of industries. Lastly, it is highly resistant to strong alkalis and resists corrosion in many non-oxidizing acids.

Super Duplex F55 Chemical Composition, %::

Cr	Ni	Mo	C	W	Cu	N	Mn	Si	P	S	Fe
24.0-26.0	6.0-8.0	3.0-4.0	0.03 max	0.5-1.0	0.5-1.0	0.2-0.3	1.0 max	1.0 max	0.03 max	0.01 max	Balance

Super Duplex F55 ASTM Specification:

Pipe & Tube	Sheet/Plate	Bar
A790, A928, A789	A240	A276

Mechanical Properties of Super Duplex F55:

Tensile Strength	109 ksi
Yield	(0.2 % offset) 80 ksi
Elongation (in 50 mm)	25 %