Incoloy 825 Chemical Process Guide - Sulfuric, Phosphoric & Seawater Applications
Date: 2026年8月17日 Categories: News Views: 266
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 Incoloy 825 Best At?
Incoloy 825 (UNS N08825) is a titanium-stabilized nickel-iron-chromium alloy (42% Ni, 21.5% Cr, 3% Mo, 2.2% Cu) that excels in sulfuric acid, phosphoric acid, and seawater — bridging the gap between 316L and the 6Mo super austenitics. Its titanium stabilization prevents sensitization (intergranular corrosion after welding), making it the default for welded chemical process equipment. Shanghai Hangbo Alloy Group supplies 825 in bars, tubes, pipes, plates, and fittings per ASTM B425/B423/B424.
Acid Resistance Data (Corrosion Rates)
| Environment | 825 (mm/yr) | 316L (mm/yr) |
|---|---|---|
| 10% H₂SO₄, 60C | < 0.1 | 3-5 |
| 40% H₂SO₄, 60C | 0.1-0.3 | Severe |
| 75% H₂SO₄, 30C | < 0.1 | Attack |
| 54% P₂O₅ (WPA), 90C | < 0.1 | 1-2 |
| Seawater, ambient | < 0.025 | Pitting |
Why Titanium Stabilization Matters
825 contains Ti (0.6-1.2%) that preferentially forms TiC, preventing chromium carbide (Cr₂₃C₆) precipitation at grain boundaries during welding. Result: no sensitization — 825 can be welded and used in the as-welded condition for most acid service, unlike 316L which requires post-weld anneal.
Incoloy 825 vs 904L (Selection)
| Property | 825 | 904L |
|---|---|---|
| Ni % | 42 | 25 |
| Mo % | 3 | 4.5 |
| PREN | ~29 | ~34 |
| Sulfuric acid | Excellent | Excellent |
| Chloride pitting | Good | Better |
| Stabilized | Yes (Ti) | No |
| Price | Similar | Similar |
Rule: 825 for acid-dominant + welding; 904L for chloride-dominant.
Product Forms & Standards
| Form | ASTM |
|---|---|
| Round Bar | ASTM B425 |
| Seamless Tube | ASTM B163 / B423 |
| Welded Pipe | ASTM B705 / B751 |
| Plate & Sheet | ASTM B424 |
| Fittings | ASTM B366 |
| Forgings | ASTM B564 |
Price Guide (2026, EXW)
| Form | Price |
|---|---|
| Round Bar Ø25-100 mm | \$22-35/kg |
| Seamless Tube | \$32-50/kg |
| Plate 6-25 mm | \$25-38/kg |
Fabrication Notes
- Welding: ERNiCrMo-3 (625) or ERNiCu-7 for dissimilar; 825 matching filler preferred.
- Machining: Work-hardens — use sharp tools, heavy feed.
- Forming: Excellent cold formability; anneal after severe forming.
Why Buy From Shanghai Hangbo?
- In-stock bars/tubes/pipes/plates.
- EN 10204 3.1 MTC per heat.
- ASTM G28 intergranular test available.
- SGS/TUV/BV inspection.
- 40+ countries shipped.
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
