For large bore piping and long runs, UNS S32520 welded pipes and tubes offer a practical way to use super duplex stainless steel without relying on seamless construction. Also designated EN 1.4507 and UR 52N+, S32520 contains 24% to 26% chromium, 3% to 4% molybdenum, 0.20% to 0.35% nitrogen and 0.5% to 2.0% copper. The combination gives the grade a 550 MPa minimum yield strength along with the corrosion resistance expected from a super duplex alloy. Amardeep Steel supplies UNS S32520 welded pipes and tubes to ASTM A789, A790 and A928. For smaller sizes or higher pressure requirements, see our UNS S32520 seamless pipes and tubes. You can also compare UNS S32750 and S32760 super duplex pipes or browse all super duplex steel pipes and tubes. Every order includes an EN 10204 3.1 mill test certificate and full heat traceability.
What Are UNS S32520 Welded Pipes and Tubes?
S32520 is a copper bearing super duplex stainless steel with a balanced austenite and ferrite structure. The copper improves resistance to sulfuric acid and to mixed acid and chloride media, while the chromium, molybdenum and nitrogen give high pitting resistance in seawater. Like other duplex grades it is generally kept below about 300°C in service.
How Welded S32520 Is Made
Strip or plate is formed and welded along a longitudinal seam with nitrogen bearing shielding gas, so the weld keeps its austenite and ferrite balance. ASTM A789 and A790 then require solution annealing and rapid cooling. Large bores are made as EFW pipe with filler to ASTM A928, where the class sets radiography and pressure testing. Confirm that S32520 is listed in the A928 edition on your order.
S32520 Welded Pipe Specifications
Parameter | Details |
|---|---|
Grade | Super Duplex S32520 |
UNS | S32520 |
Standards | ASTM A789 / ASME SA789 (tube), ASTM A790 / ASME SA790 (pipe), ASTM A928 (EFW pipe), EN 10217-7 (1.4507) |
Type | Welded tube and pipe, longitudinal seam, TIG or plasma welded; larger bores as EFW pipe with filler |
Size Range | Tube and pipe sizes to the purchase specification |
Schedules | SCH 5S, 10S, 40S, 80S and specified wall |
Length | Random, fixed and cut lengths |
Ends | Plain end and bevelled end |
Heat Treatment | Solution annealed and rapidly cooled after welding |
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 / A928 |
S32520 Welded Pipe Size and Weight Chart
NPS | OD (mm) | SCH 10S wall / weight | SCH 40S wall / weight |
|---|---|---|---|
1/2" | 21.34 | 2.11 mm / 0.99 kg/m | 2.77 mm / 1.26 kg/m |
3/4" | 26.67 | 2.11 mm / 1.27 kg/m | 2.87 mm / 1.67 kg/m |
1" | 33.40 | 2.77 mm / 2.08 kg/m | 3.38 mm / 2.49 kg/m |
1 1/2" | 48.26 | 2.77 mm / 3.09 kg/m | 3.68 mm / 4.02 kg/m |
2" | 60.33 | 2.77 mm / 3.91 kg/m | 3.91 mm / 5.41 kg/m |
3" | 88.90 | 3.05 mm / 6.42 kg/m | 5.49 mm / 11.22 kg/m |
4" | 114.30 | 3.05 mm / 8.31 kg/m | 6.02 mm / 15.97 kg/m |
6" | 168.28 | 3.40 mm / 13.74 kg/m | 7.11 mm / 28.08 kg/m |
8" | 219.08 | 3.76 mm / 19.84 kg/m | 8.18 mm / 42.27 kg/m |
Wall thickness to ASME B36.19. Weights in kg/m, worked out as (OD minus wall) x wall x π x 7.8 / 1000. Heavier schedules and specified walls on request.
S32520 vs S32550 vs S32750
Property | S32520 | S32550 | S32750 |
|---|---|---|---|
Chromium | 24.0 to 26.0% | 24.0 to 27.0% | 24.0 to 26.0% |
Molybdenum | 3.0 to 4.0% | 2.9 to 3.9% | 3.0 to 5.0% |
Nitrogen | 0.20 to 0.35% | 0.10 to 0.25% | 0.24 to 0.32% |
Copper | 0.50 to 2.00% | 1.50 to 2.50% | 0.50% max |
Min. tensile / yield | 770 / 550 MPa | 760 / 550 MPa | 800 / 550 MPa |
PREN (spec range) | 37.1 to 44.8 | 35.2 to 43.9 | 37.7 to 47.6 |
PREN is worked out as Cr + 3.3 Mo + 16 N, using the minimum and maximum of each specified range. Strength values are ASTM A790 minimums.
For the higher copper grade, see our UNS S32550 welded pipes and tubes. For copper free super duplex in seawater, see our UNS S32750 and S32760 super duplex pipes.
Applications of S32520 Welded Pipes and Tubes
- Sulfuric and phosphoric acid process lines
- Offshore seawater, firewater and cooling water headers
- Desalination brine and intake piping
- Flue gas desulfurization ducting and spray lines
- Heat exchanger tubes in chloride bearing water; see our heat exchanger tubes
Testing and Documentation
Every order of S32520 welded 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 test, with flange test on tube
- Hydrostatic or eddy current test on every length
- Weld seam radiography for ASTM A928 classes that call for it
- ASTM G48 pitting test and ferrite content check on weld and base metal on request
- Visual and dimensional inspection, including weld bead height
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 Welded Pipes & Tubes
Send us the OD or NB, wall or schedule, standard (A789, A790 or A928), 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.
Which standards cover S32520 welded pipe?
ASTM A790 covers welded pipe, ASTM A789 covers welded tube and ASTM A928 covers electric fusion welded pipe with filler. EN 10217-7 covers 1.4507 welded tube.
Is welded S32520 as corrosion resistant as seamless?
When the weld is made with nitrogen bearing shielding gas and the pipe is solution annealed after welding, as ASTM A789 and A790 require, the weld keeps a balanced structure close to the base metal.
What is the difference between S32520 and S32550?
Both are copper bearing super duplex grades. S32550 has more copper (1.5% to 2.5%) and less nitrogen, while S32520 has more nitrogen, which gives it a higher minimum PREN.
