General
Properties
LDX 2101 is a low-nickel, nitrogen
enhanced lean duplex stainless steel
developed for general-purpose use. The
austenitic-ferritic (duplex) structure of the
alloy is balanced to approximately equal
amounts of ferrite and austenite in the
solution-annealed condition.
The high chromium and nitrogen content of
LDX 2101, combined with an addition of
molybdenum, provide very good resistance to
localized and uniform corrosion. The duplex
microstructure contributes to the alloys high
strength and resistance to chloride stress-corrosion
cracking. LDX 2101 possesses both
superior strength and greater chloride stress-corrosion
cracking resistance than
conventional 300 series stainless steels.
The corrosion resistance of LDX 2101 is
generally good making it suitable for use in a
wide variety of applications. In most
environments, it is superior to 304L stainless
steel and comparable to the molybdenum
containing 316L stainless steel.
The enhanced mechanical strength of LDX
2101 is far superior to conventional 300 series
stainless steels enabling it to be used in
thinner cross-sections which can provide
significant cost savings to the end user.
LDX 2101 exhibits good abrasion and
erosion resistance and can be fabricated
using standard shop practices developed for
duplex stainless steels.
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Applications
Air Pollution Control
External absorber and outlet
duct reinforcements
Biofuels
Biodiesel and Ethanol plants
and tanks
Chemical Process Equipment
Pressure vessels, heat exchangers,
tanks, piping systems and tankers
Food and Beverage Process Equipment
Palm oil and wine storage tanks
Infrastructure
Bridges, flood gates, sluice gates
Pulp and Paper
Hydrogen peroxide bleaching reactors,
white liquor storage tanks, digesters,
washers, paper machine parts
Seawater Treatment
Desalination system chambers and
evaporators
Water and Wastewater Treatment
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Standards
ASTM...............A 240
ASME............... SA 240
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Chemical Analysis
Typical Values (Weight %)
| Cr |
Ni |
Mn |
Mo |
N |
21.0 min. -
22.0 max.
|
1.35 min. -
1.70 max. |
4.00 min. -
6.00 max. |
0.10 min. -
0.80 max. |
0.20 min. -
0.25 max. |
| Cr |
Si |
P |
Cu |
N |
Fe |
| 0.040 max. |
1.00 max. |
0.040 max. |
0.10 min. -
0.80 max. |
0.030 max. |
Balance* |
* Alloy predominates remaining composition. Other elements may be present only in
minimal quantities.
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Physical
Properties
| |
Temperature, ºF |
| 68 |
200 |
400 |
600 |
| Density |
lb/in3 |
0.28 |
|
|
|
| Modules of Elasticity |
x 106 psi |
29 |
28 |
27 |
26 |
| Poissons Ratio |
|
0.3 |
|
|
|
| Linear Expansion |
x 10-6 in/in/°F |
— |
7.2 |
7.5 |
7.5 |
| Thermal Conductivity |
Btu/ft/h °F |
8.7 |
9.3 |
9.8 |
10.4 |
| Thermal Capacity |
J/kg °F |
500 |
530 |
560 |
590 |
| Electric Resistivity |
micro-ohms•meter |
0.80 |
0.85 |
0.90 |
1.00 |
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Mechanical
Properties
| |
Minimum values
(.625" Plate) |
Typical values
(.625" Plate) |
| 0.2% Yield Strength |
ksi |
65 |
69 |
| Tensile Strength |
ksi |
94 |
101 |
| Elongation |
% |
30 |
38 |
| Hardness (Brinell) |
HB |
290 (max) |
225 |
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Design Stress Allowance
One of the advantages of nitrogen-enriched duplex stainless steels is their
higher strength levels in comparison to conventional austenitic stainless steels.
This allows for construction of units with thinner cross-sections. This weight
savings can dramatically reduce the material and fabrication cost of a vessel.
ASME Boiler & Pressure Vessel Code, Section VIII, Division 1, Allowable
Stress Values, ksi
| Alloy |
200 °F |
300 °F |
400 °F |
500 °F |
600 °F |
| LDX 2101 |
26.9 |
25.6 |
24.7 |
24.7 |
24.7 |
| 304L |
20.0 |
18.9 |
18.3 |
17.5 |
16.6 |
| 316L |
20.0 |
20.0 |
19.3 |
18.0 |
17.0 |
| 2205 |
25.7 |
24.8 |
23.9 |
23.3 |
23.1 |
| 2304 |
24.0 |
22.5 |
21.7 |
21.3 |
21.0 |
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Corrosion Properties
The 300 series stainless steels are used extensively in numerous process
industries due to their overall general corrosion resistance. The corrosion
resistance of LDX 2101 is generally better than 304L and comparable to 316L
making it suitable for use in a wide variety of industries and applications.
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Chloride Pitting Resistance
The pitting resistance of an austenitic stainless steel can be related directly
to alloy composition, where chromium, molybdenum and nitrogen are a weight
%. The Pitting Resistance Equivalent Number (PREN) uses the following
formula to measure an alloy’s relative pitting resistance - the higher the
number, the better the pitting resistance.
PREN = %Cr + 3.3Mo + 30N
The following chart compares the PREN for LDX 2101 with other common stainless steels.
Pitting Resistance Equivalent PREN = %Cr + 3.3Mo + 30N
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Crevice Corrosion Resistance
The Critical Crevice Corrosion Temperature (CCCT) test is often used to
compare the crevice corrosion resistance of various alloys.
CPT, ºC
Typical critical crevice corrosion temperature according to ASTM G48 Method F |
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Stress-Corrosion
Cracking Resistance
Chloride stress-corrosion
cracking (SCC) is one of the most
serious forms of localized
corrosion. Higher temperatures
and reduced pH will increase the
probability of SCC. The onset of
SCC is one of the most common
reasons for stainless equipment
failure. Because of its duplex
structure LDX 2101 offers
excellent resistance to SCC.
Results from U-bend testing in a
40% CaCl2 boiling solution
(100ºC) for 500 hours
| |
Longitudinal/Transverse |
| LDX 2101 |
No SSC |
| 304L |
SSC Cracking (<150hrs) |
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General Corrosion
General corrosion is
characterized as a uniform attack
on a surface in contact with a
corrosive medium. The resistance
to uniform corrosion in sulfuric
acid is shown below. LDX 2101 is
superior to 304L and in some
cases comparable to 316L.
Isocorosion curves, 0.1 mm/year,
in sulfuric acid
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LDX 2101® is a registered trademark
of Outokumpu Stainless
|
