1. Basic Information
| Item | Details |
|---|---|
| Alloy Grade | Hastelloy C276 |
| UNS Number | N10276 |
| European Norm | W.Nr. 2.4819 |
| Chinese Standard | NS334 |
| Alloy Type | Nickel-Chromium-Molybdenum-Tungsten Austenitic Corrosion-Resistant Alloy |
| Key Feature | Exceptional resistance to a wide range of corrosive environments, including pitting, crevice corrosion, and chloride stress corrosion cracking |
2. Chemical Composition (ASTM B574 Standard, wt%)
| Element | Min. | Max. |
|---|---|---|
| Nickel (Ni) | Balance | – |
| Chromium (Cr) | 14.5% | 16.5% |
| Molybdenum (Mo) | 15.0% | 17.0% |
| Tungsten (W) | 3.0% | 4.5% |
| Iron (Fe) | 4.0% | 7.0% |
| Cobalt (Co) | – | 2.5% |
| Manganese (Mn) | – | 1.0% |
| Silicon (Si) | – | 0.08% |
| Carbon (C) | – | 0.01% |
| Phosphorus (P) | – | 0.04% |
| Sulfur (S) | – | 0.01% |
| Vanadium (V) | – | 0.35% |
3. Mechanical Properties (Annealed Condition, Room Temperature)
| Property | Typical Value | ASTM B574 Requirement |
|---|---|---|
| Ultimate Tensile Strength (UTS) | ≥ 790 MPa (115 ksi) | ≥ 690 MPa (100 ksi) |
| Yield Strength (0.2% Offset) | ≥ 345 MPa (50 ksi) | ≥ 275 MPa (40 ksi) |
| Elongation (in 50mm) | ≥ 40% | ≥ 40% |
| Hardness (Brinell, HB) | ≤ 210 | ≤ 240 |
| Modulus of Elasticity | 205 GPa (29.7×10⁶ psi) | – |
4. Corrosion Resistance (Core Selling Points)
Chloride Corrosion Resistance: Outstanding resistance to pitting and crevice corrosion in seawater, brine, and chloride solutions. Suitable for long-term service in boiling 10% hydrochloric acid. Excellent resistance to chloride stress corrosion cracking (SCC), far superior to 316L and 2205 duplex stainless steel. Acid Resistance: Resistant to sulfuric, hydrochloric, phosphoric, and acetic acids. Excellent performance in wet chlorine and hypochlorite solutions. Withstands nitric-hydrofluoric mixed acid (unattainable for stainless steels). High-Temperature Corrosion: Annealed alloy can be used long-term at temperatures up to 1093°C (2000°F), with oxidation resistance up to 980°C. Resistant to high-temperature sulfidation and chlorination, ideal for flue gas desulfurization (FGD) systems. Intergranular Corrosion Resistance: Ultra-low carbon content (≤0.01%) eliminates intergranular corrosion risk after welding, no post-weld heat treatment required.
5. Physical Properties
| Property | Typical Value |
|---|---|
| Density | 8.89 g/cm³ (0.321 lb/in³) |
| Melting Range | 1325~1370°C (2417~2498°F) |
| Coefficient of Thermal Expansion (20~100°C) | 11.2×10⁻⁶ /°C (6.2×10⁻⁶ /°F) |
| Thermal Conductivity (20°C) | 9.8 W/(m·K) |
| Specific Heat Capacity (20°C) | 427 J/(kg·K) |
| Magnetic Property | Non-magnetic (Austenitic structure) |
6. Fabrication & Welding
- Heat Treatment: Solution annealing at 1150~1175°C, followed by rapid water quenching to eliminate stress and ensure corrosion resistance.
- Welding: Compatible with TIG, MIG, and SMAW processes. Recommended filler wire: ERNiCrMo-4. No post-weld heat treatment required.
- Cold Working: Good formability for cold bending and stamping, low work hardening rate.
- Machining: Similar to austenitic stainless steel, use carbide tools with low speed and high feed.
7. Typical Applications
- Chemical processing: FGD systems, acid pickling equipment, chloride reactors
- Oil & gas: Downhole tubing, production equipment, sour gas environments
- Environmental engineering: Waste incineration flue gas treatment, wastewater treatment
- Pharmaceutical: Pharmaceutical reactors, corrosive medium piping
- Marine: Seawater desalination systems, marine scrubbers
8. Concise Version (For Post List Excerpt, Ready-to-Use)
Hastelloy C276 (UNS N10276)
A nickel-chromium-molybdenum-tungsten austenitic corrosion-resistant alloy with 15-17% Mo, 14.5-16.5% Cr, and ultra-low carbon (≤0.01%).
Exceptional resistance to boiling hydrochloric acid, chloride pitting/crevice corrosion, and stress corrosion cracking.
Ideal for FGD systems, chemical pickling, and oil & gas downhole applications. Annealed condition: UTS ≥ 690MPa, elongation ≥ 40%, excellent weldability with no post-weld heat treatment required.