
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
Allows Now offers a large variety of products in Duplex
Stainless Steel alloys such as tubing, seamless- and welded pipe,
butt weld fittings, flanges, round bar and plate products:
Duplex Stainless Steels
Ferritic Austenitic
UNS S31803 UNS S32205
|
Tubing
Seamless |
1/16" - 2" OD |
0.016" - 0.250" WT |
3 mm - 50 mm OD |
0.5 mm - 6.0 mm WT |
Tubing
Welded |
1/2" - 6" OD |
0.035" - 0.500" WT |
12 mm - 150 mm OD |
1.0 mm - 12.0 mm WT |
Pipe
Seamless & Welded |
1/2" - 36" |
Sch 10S thru Sch XXS |
Butt Weld Fittings
Seamless & Welded |
1/2" - 36" |
Sch 10S thru Sch XXS |
Flanges
WN & Blind |
1/2" - 36" |
Sch 10S thru Sch XXS
150lbs thru 2500lbs |
Round Bar |
1/2" - 12" |
Plate |
1/8" - 3" thick |
Called duplex because of its mixed microstructure with about
equal proportions of ferrite and austenite, duplex stainless
steels are a family of grades, which range in corrosion performance
depending on their alloy content.
BENEFITS OF DUPLEX STAINLESS STEEL
- High strength
- A cost-effective alternative to austenitic stainless steel
316L.
- High resistance to pitting, crevice corrosion resistance
- High resistance to stress corrosion cracking, corrosion fatigue
and erosion,
- Good sulfide stress corrosion resistance,
- Low thermal expansion and higher heat conductivity than austenitic
steels,
- Good workability and weldability,
- High energy absorption.
DUPLEX STAINLESS STEEL APPLICATIONS
- Heat exchangers, tubes and pipes for production and handling
of gas and oil,
- Heat exchangers and pipes in desalination plants,
- Pressure vessels, pipes, tanks and heat exchangers for processing
and transport of various chemicals,
- Pressure vessels, tanks and pipes in process industries handling
solutions containing chlorides,
- Rotors, fans, shafts and press rolls where the high corrosion
fatigue strength can be utilized,
- Cargo tanks, piping and welding consumables for chemical
tankers.
UNS S31803 |
Carbon |
Chromium |
Manganese |
Molybdenum |
Nitrogen |
Nickel |
Phosphorus |
Sulfur |
Silicon |
0.030 max |
21.0-23.0 |
2.00 max |
2.50-3.50 |
0.08-0.20 |
4.50-6.50 |
0.030 max |
0.020 max |
1.00 max |
UNS S32205 |
Carbon |
Chromium |
Manganese |
Molybdenum |
Nitrogen |
Nickel |
Phosphorus |
Sulfur |
Silicon |
0.030 max |
22.0-23.0 |
2.00 max |
3.00-3.50 |
0.14-0.20 |
4.50-6.50 |
0.030 max |
0.020 max |
1.00 max |
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
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 |