Alloy LDX 2101® Duplex Stainless Steel Plate – Strength, Durability & Corrosion Resistance
Sandmeyer Steel Company maintains an extensive inventory of LDX 2101 stainless steel plate in thicknesses from 3/16″ (4.8mm) through 2.0″ (50.8mm). The alloy is a low nickel, lean duplex stainless steel possessing both superior strength and chloride stress-corrosion cracking resistance when compared to 300 series stainless steels.
Available thicknesses for Alloy LDX 2101®:
| 3/16" | 1/4" | 5/16" | 3/8" | 1/2" | 5/8" | 3/4" |
| 4.8mm | 6.3mm | 7.9mm | 9.5mm | 12.7mm | 15.9mm | 19mm |
| 7/8" | 1" | 1 1/4" | 1 1/2" | 1 3/4" | 2" | |
| 22.2mm | 25.4mm | 31.8mm | 38.1mm | 44.5mm | 50.8mm |
LDX 2101 (UNS S32101) is a 21.5% chromium, 5% manganese, 1.5% nickel, 0.45% molybdenum lean duplex stainless steel with corrosion resistance superior to 304L and comparable to 316L. LDX 2101 possesses both superior strength and greater chloride stress-corrosion cracking resistance than conventional 300 series stainless steels.
The enhanced mechanical strength of LDX 2101 enables it to be used in thinner cross-sections which can provide significant cost savings to the end user. LDX 2101 was designed to be a low nickel general purpose substitute for 304 and 304L.
Specification Sheet Overview
for Alloy LDX 2101® (UNS S32101)
EN 1.4162:
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.
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
Chemical Analysis
Typical Values (Weight %)
| Chromium | 21.0 min. - 22.0 max. | Nickel | 1.35 min. - 1.70 max. |
| Manganese | 4.00 min. - 6.00 max. | Molybdenum | 0.10 min. - 0.80 max. |
| Nitrogen | 0.20 min. - 0.25 max. | Chromium | 0.040 max. |
| Silicon | 1.00 max. | Phosphorus | 0.040 max. |
| Copper | 0.10 min. - 0.80 max. | Nitrogen | 0.030 max. |
| Iron | Balance* |
* Alloy predominates remaining composition. Other elements may be present only in minimal quantities.
Physical Properties
| 68 | 200 | 400 | 600 | ||
| Density | lb/in3 | 0.28 | |||
| Modules of Elasticity | x 10sup>6 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 |
Mechanical Properties
(.625" Plate) | (.625" Plate) |
||
|---|---|---|---|
| 0.2% Offset Yield Strength | ksi | 65 | 69 |
| Tensile Strength | ksi | 94 | 101 |
| Elongation | % | 30 | 38 |
| Hardness (Brinell) | HB | 290 (max) | 225 |
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 |
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.
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
Crevice Corrosion Resistance
The Critical Crevice Corrosion Temperature (CCCT) test is often used to compare the crevice corrosion resistance of various alloys.
Typical critical crevice corrosion temperature according to ASTM G48 Method F
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) |
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
Alloy LDX 2101® Duplex Stainless Steel – Frequently Asked Questions
1. What is Alloy LDX 2101® stainless steel?
Alloy LDX 2101® (UNS S32101) is a lean duplex stainless steel containing approximately 21.5% chromium, 5% manganese, and 1.5% nickel. It offers a duplex structure with equal parts ferrite and austenite, providing superior strength, chloride stress-corrosion cracking resistance, and corrosion resistance compared to 304L, and comparable to 316L.
2. What are common applications for LDX 2101 stainless steel plate?
LDX 2101 is suitable for highly corrosive and load-bearing environments, including:
• Desalination system chambers and seawater evaporators
• Biofuel and ethanol plant tanks
• Pressure vessels, heat exchangers, and chemical tankers
• Bridges, sluice gates, and other infrastructure components
• Hydrogen peroxide bleaching reactors and white liquor storage tanks
• Floodgate components and wastewater treatment systems
3. What are the mechanical properties of LDX 2101?
Typical values for 0.625″ plate:
• Yield Strength (0.2% offset): 69 ksi (minimum: 65 ksi)
• Ultimate Tensile Strength: 101 ksi (minimum: 94 ksi)
• Elongation: 38% (minimum: 30%)
• Hardness: 225 Brinell (maximum: 290)
4. What are the physical properties of Alloy LDX 2101?
• Density: 0.28 lbs/in³
• Modulus of Elasticity: 29. x 10sup>6 psi at 68°F
• Thermal Conductivity: 8.7–10.4 BTU/ft·h·°F (increases with temp)
• Electrical Resistivity: 0.80–1.00 micro-ohms•meter (68–600°F)
5. What is the corrosion resistance of LDX 2101 compared to other stainless steels?
LDX 2101 offers corrosion resistance better than 304L and comparable to 316L in most environments. It performs well against uniform corrosion, crevice corrosion, and pitting, especially in chloride-bearing solutions.
6. What is the Pitting Resistance Equivalent Number (PREN) of LDX 2101?
Using the formula PREN = %Cr + 3.3Mo + 30N, LDX 2101 achieves a strong score relative to other austenitic grades, reflecting its superior pitting resistance due to the inclusion of chromium, molybdenum, and nitrogen.
7. How resistant is LDX 2101 to crevice corrosion?
LDX 2101 demonstrates typical performance in ASTM G48 crevice corrosion testing. It maintains corrosion resistance in environments where conventional stainless steels like 304L and 316L typically fail.
8. Is Alloy LDX 2101 resistant to stress-corrosion cracking (SCC)?
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.
9. How does LDX 2101 perform in general corrosion?
LDX 2101 offers strong resistance to sulfuric acid and other common industrial environments. In many conditions, it outperforms 304L and matches or exceeds 316L’s resistance.
10. What specifications apply to Alloy LDX 2101 plate?
• ASTM A240
• ASME SA240
11. What thicknesses of Alloy LDX 2101 plate does Sandmeyer Steel stock?
Sandmeyer Steel stocks LDX 2101 plate in thicknesses ranging from 3/16″ (4.8 mm) through 2″ (50.8 mm).
Contact a Sandmeyer Steel Company Expert