Hastelloy C-4 vs C-276 - Full Comparison Guide for Chemical Applications | Shanghai Hangbo Alloy Group
Date: 2026年8月19日 Categories: News Views: 293
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-4 and C-276?
Hastelloy C-4 (UNS N06455) and Hastelloy C-276 (UNS N10276) are both nickel-chromium-molybdenum alloys, but C-4 was developed as a stabilized version of C-276 with lower iron (3% vs 5%) and no tungsten — giving it superior thermal stability after welding. C-276 has higher Mo (16%) + W (3.5%) for slightly better reducing-acid and pitting resistance. Choose C-4 for welded chemical equipment requiring post-weld stability; choose C-276 for the broadest general corrosion envelope including hot HCl.
Composition Comparison (wt.%)
| Element | C-4 (N06455) | C-276 (N10276) |
|---|---|---|
| Nickel | Balance | Balance |
| Molybdenum | 15-17.5 | 15-17 |
| Chromium | 14-18 | 14.5-16.5 |
| Iron | 3 max | 4-7 |
| Tungsten | -- | 3-4.5 |
| Cobalt | 2 max | 2.5 max |
| Carbon | 0.015 max | 0.01 max |
Corrosion Performance Comparison
| Environment | C-4 | C-276 | Better |
|---|---|---|---|
| Hot HCl (reducing) | Good | Excellent | C-276 |
| H₂SO₄ mixtures | Good | Excellent | C-276 |
| Oxidizing acids (HNO₃) | Good | Good | Tie |
| Seawater / chlorides | Excellent | Excellent | Tie |
| After-welding stability | Excellent | Good | C-4 |
| Thermal cycling | Excellent | Good | C-4 |
The Key Difference: Post-Weld Stability
C-4's chemistry (low Fe, no W) minimizes precipitation of mu-phase and sigma-phase in the heat-affected zone during welding. This means:
- C-4: Can be used as-welded in most service without PWHT — the preferred choice for complex welded fabrications.
- C-276: Requires careful heat-input control; for severe service, PWHT (solution anneal 1121C) may be specified.
Mechanical Properties (Annealed)
| Property | C-4 | C-276 |
|---|---|---|
| Tensile | >= 690 MPa | >= 690 MPa |
| Yield | >= 275 MPa | >= 285 MPa |
| Elongation | >= 40% | >= 40% |
| Density | 8.64 g/cm3 | 8.89 g/cm3 |
Price Comparison (2026, EXW)
| Form | C-4 | C-276 |
|---|---|---|
| Round Bar | \$52-80/kg | \$55-85/kg |
| Plate | \$55-85/kg | \$58-88/kg |
| Tube | \$65-100/kg | \$68-105/kg |
Pricing is nearly identical — selection should be driven by application, not price.
FAQ
Q1: Is Hastelloy C-4 better than C-276?
For welded fabrications needing post-weld stability, yes. For the broadest acid resistance (especially hot HCl), C-276 is better.
Q2: What is UNS N06455?
N06455 is Hastelloy C-4. N10276 is Hastelloy C-276.
Q3: Can C-4 replace C-276?
In many chemical services, yes. In hot reducing HCl, C-276 remains superior due to tungsten.
Q4: Which is more expensive?
They are priced nearly identically.
Q5: What does Shanghai Hangbo supply?
Both C-4 and C-276 in bars, tubes, plates, 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
