Hastelloy C276 UNS N10276: Chemical Composition & Material Properties

When specifying materials for aggressive chemical processing, flue gas desulfurization, or sour gas environments, engineers require absolute precision in chemistry and verified mechanical data. Hastelloy C276 (UNS N10276 / W.Nr. 2.4819)​ is a nickel-molybdenum-chromium wrought alloy with tungsten addition, recognized globally for its versatility in resisting both oxidizing and reducing corrosive media.

At Shanghai COCESS Special Alloys Co., Ltd, we supply Hastelloy C276 in plate, sheet, bar, pipe, and flange forms, fully compliant with ASTM B575, B574, B622, and B619 standards. The following technical breakdown outlines the exact chemical boundaries and physical-mechanical properties that define this alloy’s performance in critical service applications.

Chemical Composition (Weight %)

The corrosion resistance of UNS N10276 is directly tied to its tightly controlled chemistry. The ultra-low carbon content (≤0.01%) is critical, as it minimizes carbide precipitation in the weld heat-affected zone, preserving intergranular corrosion resistance without requiring post-weld solution heat treatment.

• Nickel (Ni): Balance (Typically ~57%)

• Molybdenum (Mo): 15.0 – 17.0%

• Chromium (Cr): 14.5 – 16.5%

• Iron (Fe): 4.0 – 7.0%

• Tungsten (W): 3.0 – 4.5%

• Cobalt (Co): ≤ 2.5%

• Manganese (Mn): ≤ 1.0%

• Vanadium (V): ≤ 0.35%

• Carbon (C): ≤ 0.01%

• Silicon (Si): ≤ 0.08%

• Phosphorus (P): ≤ 0.04%

• Sulfur (S): ≤ 0.03%

Physical Properties

These constants are essential for design calculations involving thermal expansion, weight load, and heat transfer efficiency.

• Density: 8.89 g/cm³ (0.321 lb/in³)

• Melting Range: 1325 – 1370 °C (2415 – 2500 °F)

• Specific Heat (20 °C): 427 J/kg·K (0.102 BTU/lb·°F)

• Thermal Conductivity (20 °C): 10.1 W/m·K (at 100°C)

• Coefficient of Thermal Expansion (20-100 °C): 11.2 × 10⁻⁶/K

• Electrical Resistivity (20 °C): 1.29 µΩ·m

• Young’s Modulus (20 °C): 205 GPa (29.8 × 10³ ksi)

• Shear Modulus: 79 GPa (11.5 × 10³ ksi)

• Poisson’s Ratio: 0.31

• Magnetic Permeability: < 1.005 (Essentially non-magnetic)

Mechanical Properties (Annealed Condition)

The following minimum values apply to material in the solution-annealed condition, per ASTM standards. Actual tensile values often exceed the minimums, typically ranging between 690–830 MPa for tensile strength.

• Tensile Strength (Rm): ≥ 690 MPa (≥ 100 ksi)

• Yield Strength (Rp0.2): ≥ 283 MPa (≥ 41 ksi)

• Elongation (A5): ≥ 40%

• Hardness: Typically ≤ 100 HRB (≤ 230 HB)

Key Performance Characteristics

• Corrosion Resistance: Exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in chloride-bearing solutions. Resists strong acids including sulfuric, hydrochloric, acetic, and phosphoric acids.

• Weldability: Excellent. Can be welded by most common techniques (TIG, MIG, SMAW) without sensitization, though filler metal ERNiCrMo-4 is recommended.

• Fabrication: Work hardens rapidly; intermediate annealing may be required during severe cold forming. Machining requires rigid setups and low cutting speeds due to high work hardening rates.

For project inquiries, material test reports (EN 10204 3.1), or specific dimensional availability regarding Hastelloy C276 plates, bars, pipes, or flanges, contact the technical sales team at Shanghai COCESS Special Alloys Co., Ltd.

Website: https://en.cocessalloys.com
Email: sales@cocessalloys.com