Hastelloy C-22 vs C-276 - Full Comparison of Localized Corrosion Resistance
Date: 2026年9月2日 Categories: News Views: 276
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 Hastelloy C-22 and C-276?
Hastelloy C-22 (UNS N06022) and Hastelloy C-276 (UNS N10276) are both Ni-Cr-Mo alloys, but C-22 was engineered for superior localized corrosion resistance — it carries more chromium (20-22.5% vs 14.5-16.5%) and less tungsten, giving it better pitting, crevice, and oxidizing-acid resistance than C-276. C-276 retains slightly better performance in strongly reducing hot HCl. Both are used in chemical processing, but C-22 is increasingly the preferred upgrade for flue-gas desulfurization (FGD), pulp bleaching, and mixed-acid service.
Composition Comparison (wt.%)
| Element | C-22 (N06022) | C-276 (N10276) |
|---|---|---|
| Nickel | Balance | Balance |
| Chromium | 20-22.5 | 14.5-16.5 |
| Molybdenum | 12.5-14.5 | 15-17 |
| Tungsten | 2.5-3.5 | 3-4.5 |
| Iron | 2-6 | 4-7 |
| Cobalt | 2.5 max | 2.5 max |
| Carbon | 0.015 max | 0.01 max |
Corrosion Performance Comparison
| Environment | C-22 | C-276 | Better |
|---|---|---|---|
| Pitting (chlorides) | Excellent | Good | C-22 |
| Crevice corrosion | Excellent | Good | C-22 |
| Oxidizing acids (HNO3) | Excellent | Good | C-22 |
| Wet chlorine / hypochlorite | Excellent | Moderate | C-22 |
| Hot HCl (reducing) | Good | Excellent | C-276 |
| H2SO4 mixtures | Excellent | Excellent | Tie |
| FGD scrubber service | Excellent | Good | C-22 |
Why Chromium Wins Localized Corrosion
Localized corrosion (pitting/crevice) is driven by chromium content. C-22's 20-22.5% Cr keeps the passive film stable in oxidizing + chloride environments where C-276's 15.5% Cr film breaks down. This makes C-22 the material of record for FGD absorber towers, bleach plants, and offshore chloride service.
Mechanical Properties (Annealed)
| Property | C-22 | C-276 |
|---|---|---|
| Tensile | >= 690 MPa | >= 690 MPa |
| Yield | >= 285 MPa | >= 285 MPa |
| Elongation | >= 45% | >= 40% |
| Density | 8.69 g/cm3 | 8.89 g/cm3 |
Price Comparison (2026, EXW)
| Form | C-22 | C-276 |
|---|---|---|
| Round Bar | \$56-86/kg | \$55-85/kg |
| Plate | \$58-90/kg | \$58-88/kg |
| Tube | \$68-106/kg | \$68-105/kg |
Pricing is essentially identical — selection should be driven by service environment.
FAQ
Q1: Is C-22 better than C-276?
For localized corrosion (pitting/crevice) and oxidizing acids, yes. For hot reducing HCl, C-276 is still preferred.
Q2: What is UNS N06022?
N06022 is Hastelloy C-22. N10276 is C-276.
Q3: Can C-22 replace C-276?
In most chemical and FGD service, yes — C-22 is the standard upgrade. Verify hot HCl duty first.
Q4: Which is more expensive?
Pricing is essentially identical.
Q5: Which is better for seawater?
C-22, thanks to higher chromium against pitting.
Q6: Which welds better?
Both weld readily with matching fillers (ERNiCrMo-10 for C-22, ERNiCrMo-4 for C-276).
Q7: What does Shanghai Hangbo supply?
Both grades in bars, tubes, plates, sheets, 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
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