2205 vs 2507 Duplex: Strength & Corrosion
Date: 2026年9月11日 Categories: News Views: 374
By Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier | ISO 9001:2015 | Est. 2012
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp (Lisa): +86 13611656360
Quick Answer: What Is the Difference Between 2205 and 2507?
2205 (UNS S32205) is the standard duplex stainless steel; 2507 (UNS S32750) is its super-duplex upgrade. Both have a ferrite-austenite microstructure giving roughly double the yield strength of 316L, but 2507 carries far more chromium (24-26% vs 22-23%), molybdenum (3-5% vs 3-3.5%), and nitrogen, pushing its PREN above 40 versus ~35 for 2205. This makes 2507 substantially more resistant to pitting, crevice corrosion, and chloride SCC — the reason it is specified for seawater and offshore service. 2205 is the workhorse (cheaper, tougher); 2507 is for the most aggressive chloride duties.
Composition Comparison (wt.%)
| Element | 2205 (S32205) | 2507 (S32750) |
|---|---|---|
| Chromium | 22-23 | 24-26 |
| Nickel | 4.5-6.5 | 6-8 |
| Molybdenum | 3.0-3.5 | 3.0-5.0 |
| Nitrogen | 0.14-0.20 | 0.24-0.32 |
| PREN | ~35 | ~42 |
Mechanical Properties Comparison
| Property | 2205 | 2507 |
|---|---|---|
| Tensile Strength | 620-880 MPa | 730-1000 MPa |
| Yield Strength (0.2%) | 450-620 MPa | 550-800 MPa |
| Elongation | 25-35% | 15-25% |
| Hardness | 25-32 HRC | 28-35 HRC |
| Toughness (impact) | Better | Lower |
Corrosion Performance Comparison
| Environment | 2205 | 2507 | Better |
|---|---|---|---|
| Seawater (ambient) | Good | Excellent | 2507 |
| Seawater (elevated temp) | Moderate | Excellent | 2507 |
| Chloride pitting | Good | Excellent | 2507 |
| Chloride SCC | Good | Excellent | 2507 |
| H2S (sour service) | Limited | Good (qualified grades) | 2507 |
| Organic acids | Excellent | Excellent | Tie |
Which One for Your Application?
| Application | Best Choice | Why |
|---|---|---|
| Chemical storage tanks | 2205 | Cost-effective strength |
| Pulp & paper digesters | 2205 | Caustic + strength |
| Seawater piping | 2507 | Chloride resistance |
| Offshore risers | 2507 | SCC + strength |
| Desalination plant | 2507 | Hot seawater |
| Structural bridges | 2205 | Strength + toughness |
Price Comparison (2026, EXW)
| Form | 2205 | 2507 |
|---|---|---|
| Plate | \$9-15/kg | \$16-26/kg |
| Bar | \$9-15/kg | \$16-26/kg |
| Tube | \$12-20/kg | \$20-32/kg |
2507 costs 60-80% more than 2205.
FAQ
Q1: Is 2507 better than 2205?
For aggressive chloride and seawater service, yes. For general chemical and structural use, 2205 delivers most of the benefit at much lower cost.
Q2: What is PREN?
Pitting Resistance Equivalent Number = %Cr + 3.3(%Mo) + 16(%N). 2205 ≈ 35, 2507 ≈ 42.
Q3: What are the UNS numbers?
S32205 = 2205; S32750 = 2507.
Q4: Which is stronger?
2507, with higher yield strength (550-800 MPa vs 450-620 MPa).
Q5: Which has better toughness?
2205 — higher ferrite-austenite balance favors impact toughness.
Q6: Which is more expensive?
2507 is typically 60-80% more expensive.
Q7: What does Shanghai Hangbo supply?
Both duplex grades in plates, bars, tubes, and fittings with EN 10204 3.1 certification. SGS/TUV/BV available.
Contact & Complete Product Range
Shanghai Hangbo Alloy Group Co., Ltd. - China Supplier
Email: sales@hangboalloy.com | WhatsApp (Lisa): +86 13611656360 | www.nickel-alloy.com
All Grades
Ni: NI200-N6 | Monel: 400-502, K-500, R-405 | Inconel: 600-740H, X-750, 725 | Incoloy: 800-27-7MO | Hastelloy: C-276-HYBRID-BC1, N | Super Austenitic: 904L-AL-6XN | Chromium-Rich: Alloy 33 | High-Strength Stainless: Nitronic 50/60, PH13-8Mo | Chlorination: Alloy 45 | Nimonic: 75-263 | Haynes: 25-HR-160 | RA: 330/333 | Precision: 1J22-4J45 | High-Strength: 18Ni250-AerMet100 | Heating: Cr20Ni80/60 | Specialty: Alloy 20-602CA
Product Forms: Bars(6-500mm) | Tubes(OD 6-610mm) | Plates(0.1-100mm) | Forgings | Welded Pipes | Fittings | Wire(0.05-10mm) | Strip(0.02-4.0mm)
SGS/BV/TUV. www.nickel-alloy.com
