Materials > Duplex
Duplex Stainless Steel
UNS S31803 - UNS S32205
Duplex Plate/Sheet
Duplex Seamless & Welded Tube
Duplex Seamless & Welded Pipe
Duplex Round Bar
Duplex Flanges F51
Duplex Specialty Forgings
Duplex Seamless & Welded BW Fittings
| Trade Name |
UNS |
6Moly Industry Specifications |
Chemical Composition |
Min.Tensile
(KSI) |
Min.Yield
(KSI) |
Elongation
% |
SAF 2205 |
UNS S31803 |
ASME SA-182 (F51), SA-240, SA-798, SA-790, SA-815
ASTM A240, A276, A479, A789, A790, A815, A923, A928,
A988 SAE J405 |
C 0.30 max
Cr 21.0-23.0 Mn 2.00 max Mo
2.50-3.50 N 0.08-0.20 Ni 4.50-6.50
P 0.030 max S 0.020 max Si
1.00 max |
90 |
65 |
25 |
| SAF 2205 |
UNS S32205 |
ASTM A240, A240M, A276, A479, A480, A480M, A798, A7901,
A815, A923, A928, A988 SAE J40 |
C 0.30 max Cr 22.0-23.0 Mn
2.00 max Mo 3.00-3.50 N 0.14-0.20
Ni 4.50-6.50 P 0.030 max S
0.020 max Si 1.00 max |
90 |
65 |
25 |
General Duplex stainless steel information
2205 is the most widely used duplex (ferritic/austenitic) stainless steel
grade. It finds applications due to both excellent corrosion resistance and
high strength. The standard duplex S31803 composition has over the years been
refined by many steel suppliers, and the resulting restricted composition
range was endorsed as UNS S32205 in 1996. Duplex S32205 gives better guaranteed
corrosion resistance, but for much of the Duplex S31803 currently produced
also complies with Duplex S32205. 2205 is not generally suitable for use at
temperatures above 300ºC as it suffers from precipitation of brittle
micro-constituents, nor below -50ºC because of its ductile-to-brittle-transition.
Duplex Applications
Chemical processing, transport and storage,
Oil and Gas exploration and processing equipment,
Marine and other high chloride environments,
Pulp and paper digesters, liquor tanks and paper machines.
Duplex Corrosion Resistance
Excellent general corrosion resistance; superior to Grade 316 in most environments.
Excellent resistance to localized corrosion including intergranular, pitting
and crevice corrosion; the CPT of 2205 is generally at least 35ºC. The
grade is also resistant to chloride stress corrosion cracking (SCC) at temperatures
of up to about 150ºC. Grade 2205 will often perform well in environments
which cause premature failure of austenitic grades. It has better resistance
to sea water then Grade 316.
Duplex Heat Resistance
Although 2205 has good high temperature oxidation resistance, this grade
- like other duplex stainless steels - suffers from embrittlement if held
for even short times at temperatures above 300ºC. If embrittled, this
can only be rectified by a full solution annealing treatment. Duplex stainless
steels are almost never used above 300ºC.
Duplex Heat Treatment
Solution treatment (annealing) - heat to 1020ºC-1100ºC and cool
rapidly. This grade cannot be hardened by thermal treatment, but does work
harden.
Source: Atlas Steels Australia
titanium
- duplex - super
duplex - 6%
moly - stainless
steels - nickel
alloys
tubing
- pipe
& pipe fittings - round
bar - plate/sheet
- flanges
- valves
- specialty
forgings