- All
- Product Name
- Product Keyword
- Product Model
- Product Summary
- Product Description
- Multi Field Search
Views: 3 Author: Shirley Publish Time: 2025-07-30 Origin: Site
In chemical processing, pollution control, oil and gas, and marine engineering, material failure is not allowed. Hastelloy C276 is a nickel-based superalloy, world famous for its super corrosion resistance and high temperature resistance This C276 alloy combines high strength, excellent fabricability, and outstanding thermal stability, making it critical components exposed to severe chemical attack, pitting, crevice corrosion, and stress corrosion cracking.
Hastelloy C276 commonly manufactured into forms such as bar stock, plate, sheet, pipe, tubing, fittings, and flanges. This article provides a comprehensive technical overview of Hastelloy C276, detailing its composition, physical and mechanical properties, material standards, comparison to Hastelloy C22.
Hastelloy C276 is a nickel-chromium-molybdenum alloy. Its chemical composition as follows:
| Composition | Value | Function |
| Nickel (Ni) | 52% | Provides the fundamental matrix, inherently resistant to chloride stress corrosion cracking (SCC) and reducing environments. It ensures good ductility and toughness. |
| Chromium (Cr) | 15.5% | Resistance to oxidizing conditions like nitric acid, chromic acid, hypochlorite solutions and enhances high-temperature oxidation resistance. It contributes to pitting and crevice corrosion resistance. |
| Molybdenum (Mo) | 16% | The cornerstone for resisting reducing acids like sulfuric, hydrochloric, phosphoric, pitting, and crevice corrosion. |
| Tungsten (W) | 3.75% | Further enhances resistance to reducing acids and localized corrosion, acting synergistically with molybdenum to broaden the alloy's protective ranges. |
| Iron (Fe) | 6% | Stabilize the microstructure and control cost, but kept at moderate levels to avoid compromising corrosion resistance in severe environments. |
| Cobalt (Co) | 2.5% | Generally present as an impurity trace, but controlled to low levels as it can potentially reduce corrosion resistance in specific media. |
| Manganese (Mn) | 1% | Acts as a deoxidizer and aids in hot workability. |
| Vanadium (V) | 0.35% | Typically controlled as an impurity; high levels can be detrimental. |
| Silicon (Si) | 0.08% | Controlled as a deoxidizer; higher levels can promote embrittlement. |
| Carbon (C) | 0.01% | Critically minimized to prevent sensitization during welding or high-temperature exposure, which could drastically reduce corrosion resistance in the heat-affected zone (HAZ). |
| Phosphorus (P) | 0.025% | Controlled as an impurity; high levels can promote hot cracking. |
| Sulfur (S) | 0.01% | Minimized to avoid hot shortness and improve weldability and hot workability. |
| Copper (Cu) | Remain | |
| Titanium (Ti) | Remain |
Hastelloy C276 has a super combination of physical, mechanical, and corrosion-resistant properties.
Physical Properties:
Density: 8.89 g/cm³ (0.321 lb/in³)
Melting Range: 1323-1371 °C (2413-2500 °F)
Specific Heat: 427 J/kg·K (0.102 Btu/lb·°F) at 20°C
Thermal Conductivity: 10.1 W/m·K (70 Btu·in/ft²·h·°F) at 20°C
Mean Coefficient of Thermal Expansion: 11.2 µm/m·°C (6.2 µin/in·°F) between 20-100°C; ~14.4 µm/m·°C (8.0 µin/in·°F) between 20-500°C
Electrical Resistivity: 1.30 µΩ·m at 20°C
Modulus of Elasticity: 205 GPa at room temperature. Decreases with increasing temperature.
Mechanical Properties:
Tensile Strength: ≥ 690 MPa (≥ 100 ksi)
Yield Strength: ≥ 283 MPa (≥ 41 ksi)
Elongation: ≥ 40%
Reduction of Area: ≥ 60%
Hardness: Typically Rockwell B ≤ 90 (Brinell ≤ 210 HB).
Elevated Temperature Strength: Hastelloy C276 retains useful strength well above room temperature. Yield strength typically exceeds 240 MPa at temperatures up to 600°C, making it suitable for moderately high-temperature applications alongside its corrosion resistance.
C276 hastelloy offers outstanding resistance to a vast array of aggressive chemicals and environments:
Oxidizing Media: Resists nitric acid, chromic acid, hypochlorites, ferric and cupric chlorides, moist chlorine gas. Superior to pure nickel or nickel-copper alloys.
Reducing Media: Excellent resistance to sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, formic acid.
Localized Corrosion: Exceptional resistance to pitting and crevice corrosion, especially in chloride-containing solutions. High Pitting Resistance Equivalent Number (PREN = %Cr + 3.3x%Mo + 16x%N ≈ 69).
Mixed Acids: Performs well in complex mixtures like nitric/hydrofluoric (HF) acids and oxidizing salts with reducing acids.
Wet Process Phosphoric Acid: Standard material for handling corrosive impurities.
Pollution Control: Resists flue gas desulfurization environments containing chlorides, fluorides, and sulfuric acid condensates.
Marine and Offshore: Excellent performance in seawater, brackish water, and marine atmospheres.
Weld Zone Stability: The low carbon content minimizes carbide precipitation in the weld heat-affected zone, maintaining corrosion resistance without requiring post-weld heat treatment in most applications.
Internationally recognized material standards is non-negotiable for ensuring the quality, consistency, traceability, and performance of Hastelloy C276 products.
ASTM (American Society for Testing and Materials):
B575: Seamless Pipe & Tube
B619 / B626: Welded Pipe & Tube
B574: Bar & Wire (Rod)
B575: Seamless Pipe & Tube
B575: Seamless Fittings
B366: Welded Fittings
B462: Forged Fittings
B564: Forging, including flanges.
B333: Plate, Sheet, and Strip
ASME (American Society of Mechanical Engineers):
SB-575 / SB-619 / SB-626 / SB-574 / SB-333 / SB-564 / SB-366 / SB-462: Corresponding ASTM specifications adopted by ASME Section II for Code construction.
ASME approved for use up to elevated temperatures.
EN / BS (European / British Standards):
EN 10204 3.1 / 3.2 Material Certification
BS 3076: Bar (NA 17 / NiMo16Cr15W)
BS EN ISO 15156-3 (NACE MR0175): For sour service (H2S) applications.
DIN (Deutsches Institut für Normung):
DIN 17752: Wrought Nickel Alloys.
DIN 17754: Wrought Nickel Alloys - Technical Delivery Conditions (Bar, Rod, Wire)
DIN 17753: Plate, Sheet, Strip
DIN 17751: Seamless Tubes
GOST (Russian Standards):
GOST P 5632: Stainless Steels and Corrosion Resisting, Heat-Resisting and Creep Resisting Alloys.
These standards rigorously define chemical composition limits, mechanical property, heat treatment procedures, specification, tolerances, and marking.
Chemical Composition:
Hastelloy C22 (UNS N06022): Higher Chromium, enhances resistance to oxidizing environments.
Hastelloy C276 (UNS N10276): High Mo and W, it enhances resistance to reducing acids and localized corrosion in purely reducing conditions without oxidizing contaminants. Tungsten (W) boosts reducing acid resistance but can make the alloy slightly more susceptible to forming detrimental phases during welding or high-temp exposure.
Corrosion Resistance:
Oxidizing Conditions: Alloy C22 is superior due to its higher Chromium content.
Reducing Acids: C276 has a slight edge in pure, non-aerated hydrochloric and sulfuric acids due to its higher Mo+W content.
Mixed Oxidizing/Reducing and Complex Environments: C22 Hastelloy is generally superior and more versatile. Its balanced composition provides outstanding resistance across a broader spectrum of mixed acids, contaminated acids, and environments where conditions shift between oxidizing and reducing. This is a very common scenario in real-world chemical processing.
Localized Corrosion: C22 generally has a higher PREN, translating to better resistance in high-chloride environments.
Stress Corrosion Cracking: Both are excellent, but hastelloy C22's thermal stability often gives it a slight edge in very severe chloride + oxidizing ion environments or where thermal cycles occur.
Fabrication and Welding:
C22 Hastelloy: Easier to fabricate and weld. Its lower carbon and tungsten content significantly reduce its susceptibility to sensitization during welding or thermal exposure. It haswWider range of suitable welding procedures.
C276 Hastelloy: Requires more careful thermal management during welding and fabrication to avoid sensitization due to its higher tungsten and iron content. While readily weldable, stricter procedures are needed to maintain optimal corrosion resistance in the HAZ. PWHT is sometimes recommended for critical service.
Thermal Stability:
C22: Superior thermal stability. Much more resistant to forming harmful intermetallic and carbide phases during prolonged exposure in the 1200°F - 1600°F (650°C - 870°C) range. This makes it better suited for high-temperature components or where thermal cycling occurs.
C276: More susceptible to precipitation of detrimental phases in the intermediate temperature range. Careful consideration for high-temperature applications.
Cost:
C276 is typically less expensive than C22. The price difference primarily stems from C22's higher Chromium content.
Our factory specializes in providing a comprehensive range of high-quality Hastelloy C276 products manufactured to exacting international standards ASTM, ASME, EN, DIN to meet many application needs:
Hastelloy C276 Bars: Round bar, hex bar, square bar. Available in hot-finished, hot-rolled, or cold-finished conditions. It used for machining shafts, valves, pumps, fasteners, fittings.
Hastelloy C276 Plate and Sheet: Available in thin sheet to heavy plate. Supplied in hot-rolled, cold-rolled, annealed, and pickled/surface treated conditions. Used for tanks, vessels, heat exchangers, scrubbers, ducting, flanges.
Hastelloy C276 Pipe and Tube:
Seamless Pipe/Tube: Critical for high-pressure, high-temperature, and corrosive fluid transport. Sizes from small bore tubing to large diameter pipe.
Welded Pipe/Tube: Economical option for less severe pressure applications, available in larger diameters.
Hastelloy C276 Fittings: Seamless and welded elbows (45°, 90°, 180°), tees (equal, reducing), reducers (concentric, eccentric), caps. Manufactured to ASTM/ASME B366 or B462 standards. It is essential for constructing corrosion-resistant piping systems.
Hastelloy C276 Flanges: Slip-on, weld neck, blind, socket weld, lap joint, threaded flanges. Manufactured to ASTM/ASME B564 or B462. Available in standard ASME B16.5, B16.47, and other specifications. Critical for connecting piping and equipment.
Hastelloy C276 Fasteners: Bolts, studs, nuts. It often used in critical bolted connections within corrosive environments.
C276 Hastelloy Forgings: Custom shapes and near-net shapes produced via open-die or closed-die forging for superior grain structure and directional strength in critical components (valve bodies, pump casings, heavy flanges).
C276 Wire: Used for electrodes, filler wire and specialized applications.
JN Company ensure consistent quality across all forms through rigorous in-process and final inspection, including chemical analysis, mechanical testing, non-destructive examination, dimensional checks, and comprehensive certification.
