Hastelloy C-276: Universal Corrosion-Resistant Nickel Superalloy
ASTM B575 / ASME SB-575 · Published: 2026-06-24 · Updated: July 2026
Hastelloy C-276 is the most versatile corrosion-resistant nickel alloy in industrial use. It resists both oxidizing and reducing environments — a dual capability that no stainless steel can match. C-276 is the go-to material for chemical...
Hastelloy C-276 is the most versatile corrosion-resistant nickel alloy in industrial use. It resists both oxidizing and reducing environments — a dual capability that no stainless steel can match. C-276 is the go-to material for chemical processing equipment exposed to mixed acids, flue gas desulfurization (FGD) scrubbers handling sulfuric and hydrochloric acid mixtures, and pharmaceutical reactors where product contamination from metal ions cannot be tolerated.
The alloy's exceptional corrosion resistance comes from its composition: 15.5% chromium (oxidizing resistance), 16% molybdenum and 4% tungsten (reducing resistance), and low carbon (0.01% max) to prevent intergranular corrosion after welding. C-276 is weldable in the as-received condition — unlike many stainless steels, it does not require post-weld solution annealing to restore corrosion resistance at weld seams.
Quick Facts
| Category | |
| Standard | ASTM B575 / ASME SB-575 |
| Density | 8.89 g/cm³ |
| Yield Strength | 355 MPa (51 ksi) |
| Tensile Strength | 790 MPa (115 ksi) |
Global Equivalents & Cross-Reference
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Frequently Asked Questions
How does C-276 compare to Inconel 625 for corrosion resistance?
C-276 is superior in reducing acids (HCl, H₂SO₄) and mixed acid environments. Inconel 625 is superior in high-temperature oxidation above 1,000°F. For wet corrosion at moderate temperatures: C-276. For high-temperature corrosion + mechanical stress: Inconel 625. Price: C-276 is typically 15-25% more expensive than 625 due to higher molybdenum and tungsten content.
What welding procedures are recommended for C-276?
Use matching filler metal (ERNiCrMo-4). GTAW is preferred; GMAW with pulsed spray transfer is acceptable for thicker sections. Maintain interpass temperature below 200°F (93°C). No preheat required. No post-weld heat treatment required — C-276 is one of the few corrosion-resistant alloys that does not require solution annealing after welding thanks to its ultra-low carbon content. Clean weld area thoroughly — remove all grease, oil, and shop dirt before welding. Contamination is the #1 cause of C-276 weld corrosion failure.
References & International Standards
- ASTM International. Standard Specifications for Steel & Metal Alloys. astm.org
- International Organization for Standardization (ISO). Metallic Materials — Cross-Reference Database. iso.org
- American Iron and Steel Institute (AISI). Steel Grade Designations & Equivalents. steel.org
- European Committee for Standardization (CEN). EN Steel Standards & Numbering System. cencenelec.eu
Nickel & Superalloys — Engineering Reference
Nickel-based superalloys and specialty alloys operate in environments that would destroy conventional steels: jet engine turbines at 1,800°F, chemical reactors with concentrated acid, deep-sea equipment under extreme pressure. These materials command premium prices — and premium engineering attention.
ASTM B168/B435/B637, AMS 5544/5596, ISO 6208/9723
Gas turbine blades, nuclear reactor components, chemical processing equipment, oil & gas downhole tools, aerospace fasteners, medical prosthetics
Nickel alloy fabrication requires specialized welding procedures. Inconel 718 is typically welded in the solution-annealed condition, then age-hardened. Hastelloy C276 requires low heat input to prevent sensitization. Always consult the mill's recommended welding parameters.