Super Duplex UNS S32520 seamless pipes and tubes are made for demanding services where high corrosion resistance and strength are both important. Also known as EN 1.4507 and UR 52N+, S32520 contains 24% to 26% chromium, 3% to 4% molybdenum, up to 0.35% nitrogen and 0.5% to 2.0% copper. The copper addition is particularly useful in sulfuric acid service, where S32520 can offer better resistance than copper free super duplex grades. Amardeep Steel supplies UNS S32520 pipes and tubes to ASTM A789 and A790 with EN 10204 3.1 mill test certificates and full heat traceability. Compare our UNS S32750 and S32760 super duplex pipes, or browse our super duplex steel pipes and tubes.
What Are UNS S32520 Seamless Pipes and Tubes?
S32520 is a super duplex stainless steel: a balanced austenite and ferrite structure with enough chromium, molybdenum and nitrogen for high pitting resistance in seawater and chloride brines. Its minimum yield of 550 MPa is about three times that of 316L. Like other duplex grades it is generally kept below about 300°C in service.
Why Copper Matters in S32520
Most super duplex grades hold copper to 0.50% or less. S32520 allows 0.50% to 2.00%, which slows attack in sulfuric acid and in mixed acid and chloride media found in fertilizer, phosphoric acid and flue gas cleaning plants. For seawater only duty, S32520 and S32750 perform alike.
S32520 Seamless Pipe Specifications
Parameter | Details |
|---|---|
Grade | Super Duplex S32520 |
UNS | S32520 |
Standards | ASTM A789 / ASME SA789 (tube), ASTM A790 / ASME SA790 (pipe), EN 10216-5 (1.4507) |
Type | Seamless, hot finished or cold drawn |
Size Range | Tube and pipe sizes to the purchase specification |
Schedules | SCH 10S, 40S, 80S, 160 and specified wall |
Length | Random, fixed and cut lengths |
Ends | Plain end and bevelled end |
Heat Treatment | Solution annealed and rapidly cooled |
Test Certificate | EN 10204 3.1, with 3.2 available on request |
S32520 Chemical Composition
Element | Content (%) |
|---|---|
Carbon (C) | 0.030 max |
Manganese (Mn) | 1.50 max |
Phosphorus (P) | 0.035 max |
Sulfur (S) | 0.020 max |
Silicon (Si) | 0.80 max |
Nickel (Ni) | 5.5 to 8.0 |
Chromium (Cr) | 24.0 to 26.0 |
Molybdenum (Mo) | 3.0 to 4.0 |
Nitrogen (N) | 0.20 to 0.35 |
Copper (Cu) | 0.50 to 2.00 |
S32520 Mechanical Properties
Property | Value |
|---|---|
Tensile Strength, min | 770 MPa (112 ksi) |
Yield Strength (0.2% offset), min | 550 MPa (80 ksi) |
Elongation in 50 mm, min | 25% |
Hardness, max | 310 HBW |
S32520 Equivalent Grades
Standard | Designation |
|---|---|
UNS | S32520 |
EN / Werkstoff | 1.4507 (X2CrNiMoCuN25-6-3) |
Common name | Super Duplex 2520, UR 52N+ |
ASTM pipe / tube | A790 / A789 |
S32520 vs S32750 vs S32760
Property | S32520 | S32750 | S32760 |
|---|---|---|---|
Chromium | 24.0 to 26.0% | 24.0 to 26.0% | 24.0 to 26.0% |
Molybdenum | 3.0 to 4.0% | 3.0 to 5.0% | 3.0 to 4.0% |
Nitrogen | 0.20 to 0.35% | 0.24 to 0.32% | 0.20 to 0.30% |
Copper | 0.50 to 2.00% | 0.50% max | 0.50 to 1.00% |
Tungsten | Not specified | Not specified | 0.50 to 1.00% |
Min. tensile / yield | 770 / 550 MPa | 800 / 550 MPa | 750 / 550 MPa |
Min. elongation | 25% | 15% | 25% |
All three are super duplex grades with a PREN above 40 at typical composition. Values are ASTM A790 minimums.
For copper free super duplex in seawater, see our UNS S32750 and S32760 super duplex pipes. For a step down in alloy, see our UNS S32205 duplex pipes and tubes.
Applications of S32520 Seamless Pipes and Tubes
- Sulfuric and phosphoric acid process lines
- Offshore seawater, firewater and cooling systems
- Desalination high pressure brine piping
- Flue gas desulfurization equipment
- Heat exchanger tubes in chloride bearing water; see our heat exchanger tubes
Testing and Documentation
Every order of S32520 seamless pipe and tube goes through the checks below at our testing facility or approved third party labs.
- Chemical analysis and PMI
- Tension and hardness tests
- Flattening and flaring tests
- Hydrostatic or eddy current test on every length
- ASTM G48 pitting test and ferrite content check on request
- Ultrasonic testing on request
- Visual and dimensional inspection
Mill test certificates are issued to EN 10204 3.1, with 3.2 available on request. You can view our approvals on the certificates page.
Packing and Marking
Each length is marked with the standard, UNS S32520, size, heat number and manufacturer name. Ends are capped, and pipes are kept apart from carbon steel and packed in bundles or wooden boxes. Read more about our packing and despatch process.
Request a Quote for UNS S32520 Seamless Pipes & Tubes
Send us the OD or NB, wall or schedule, standard, any corrosion test needs, length and quantity, and our team will reply with price and delivery. Use the enquiry form or reach us through the contact page.
Frequently Asked Questions
What is UNS S32520?
UNS S32520 (EN 1.4507, UR 52N+) is a super duplex stainless steel with 24% to 26% chromium, 5.5% to 8% nickel, 3% to 4% molybdenum, 0.20% to 0.35% nitrogen and 0.5% to 2.0% copper.
What is the difference between S32520 and S32750?
Both are 25% chromium super duplex grades. S32520 allows up to 2.0% copper for better sulfuric acid resistance, while S32750 holds copper to 0.50% maximum.
Which standards cover S32520 seamless pipe?
ASTM A790 covers seamless pipe and ASTM A789 covers seamless tube. EN 10216-5 covers 1.4507 seamless tube.
What are the mechanical properties of S32520?
ASTM A790 sets 770 MPa minimum tensile strength, 550 MPa minimum yield strength, 25% minimum elongation and 310 HBW maximum hardness.
