A890 4A
Duplex Stainless
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Comparative Classifications
ASTM Specification
A890
ASME Specification
SA890
UNS (Cast)
J92205
UNS (Wrought)
S31803
SAE
2205
AISI
Carbon:
0.03% Max
Silicon:
1.00% Max
Phosphorus:
0.04% Max
Manganese:
1.50% Max
Sulfur:
0.02% Max
Chromium:
21.00 - 23.50%
Nickel:
4.50 - 6.50%
Molybdenum:
2.50 - 3.50%
Nitrogen:
0.10 - 0.30%
Nitrogen + Carbon:
Vanadium:
Tungsten:
Aluminum
Titanium:
Copper:
1.00% Max
Columbium:
Barium:
Boron:
Zirconium:
Cerium + Lanthanum:
Iron:
Residual Elements:
Tensile Strength:
90 ksi Min
Elongation at 2 in:
25% Min
Reduction of Area:
Yield Strength:
60 ksi Min
Chemical Composition
Alloy Specification
A995 4A
J92205
Related Alloys
Frequently Asked Questions
Q. What is duplex stainless steel?
A. Duplex stainless steel is an alloy with a two-phase metallurgical structure consisting of austenite and ferrite in almost equal parts. The content composition of duplex steel has a higher level of chromium and molybdenum, lower nickel and a percentage of nitrogen between 0.05 to 0.50%. This composition, coupled with heat treatment, makes duplex stainless better at corrosion resistance (chloride stress corrosion and chloride pitting corrosion especially) and higher strength when compared to austenitic stainless.