English 
Spanish 
Russian 
Turkish 
French 
Korean 
German 
Italian 
Shanghai Toko Tech Co., Ltd. is a professional manufacturer and supplier of high-performance special alloy pipes and components. Its ALLOY 800 (UNS N08800), 800H (UNS N08810), and 800HT (UNS N08811) seamless coiled tubing represent a family of nickel-iron-chromium alloys renowned for their exceptional strength and resistance to oxidation, carburization, and sulfidation at high temperatures. These alloys are specifically designed for continuous service in elevated temperature environments where resistance to corrosion and thermal stability are critical.
Key Features & Advantages:
- Excellent High-Temperature Strength: The 800 series alloys maintain good mechanical properties and structural stability at temperatures up to 1100°F (593°C) for continuous service, and even higher for intermittent service.
- Outstanding Oxidation & Carburization Resistance: The combination of nickel, chromium, and iron provides exceptional resistance to oxidation, carburization, and sulfidation, making these alloys ideal for furnace applications and petrochemical processing.
- Good Resistance to Stress Corrosion Cracking: Demonstrates excellent resistance to chloride-ion stress corrosion cracking, outperforming many standard stainless steels.
- Stability in High-Temperature Environments: The controlled carbon and aluminum/titanium content (in 800H/HT) ensures microstructural stability through the formation of strengthening carbides and carbonitrides during prolonged exposure to high temperatures.
- Seamless & Continuous Length: The seamless structure ensures maximum integrity for critical high-pressure and high-temperature applications. The long coiled length eliminates potential weak points from welds and simplifies installation in complex heating systems.
Material Composition (Chemical Requirements per ASTM B407/163):
The high-temperature performance of the 800 series is achieved through precise chemical control.
| Element | ALLOY 800 (N08800) | ALLOY 800H (N08810) | ALLOY 800HT (N08811) | Role |
| Nickel (Ni) | 30.0-35.0 | 30.0-35.0 | 30.0-35.0 | Provides high-temperature strength and resistance to oxidation and carburization |
| Chromium (Cr) | 19.0-23.0 | 19.0-23.0 | 19.0-23.0 | Enhances resistance to oxidation, sulfidation, and high-temperature corrosion |
| Iron (Fe) | 39.5 min | 39.5 min | 39.5 min | Forms the base matrix, providing solid solution strength |
| Carbon (C) | 0.10 max | 0.05-0.10 | 0.06-0.10 | Controlled for high-temperature strength and stability |
| Aluminum (Al) | 0.15-0.60 | 0.15-0.60 | 0.25-0.60 | Improves resistance to oxidation and high-temperature scaling |
| Titanium (Ti) | 0.15-0.60 | 0.15-0.60 | 0.25-0.60 | Enhances strength through precipitation hardening |
| Al+Ti | – | – | 0.85-1.20 | Combined requirement for 800HT for optimal strengthening |
Typical Specifications (Customizable):
- Material Grade:
- UNS N08800 / W. Nr. 1.4876 / ASTM B407 (ALLOY 800)
- UNS N08810 / W. Nr. 1.4958 / ASTM B407 (ALLOY 800H)
- UNS N08811 / W. Nr. 1.4959 / ASTM B407 (ALLOY 800HT)
- Outer Diameter (O.D.): φ3.18 mm ~ φ27 mm (Common range for coils)
- Wall Thickness (W.T.): 0.5 mm ~ 2.0 mm (Varies with O.D.)
- Coil Length: Several hundred meters per continuous coil (exact length depends on O.D. and W.T.)
- Standard: ASTM B407, ASTM B163
Primary Applications:
This family of high-temperature alloys is specified for demanding applications across various industries:
- Heat Treating Industry: Radiant tubes, muffles, retorts, and basket fixtures in carburizing, nitriding, and annealing furnaces.
- Petrochemical Processing: Steam methane reformer tubes, hydrogen reformer assemblies, and cracking tubes in ethylene production.
- Power Generation: Superheater and reheater tubes, heat exchangers, and other high-temperature components in fossil fuel power plants.
- Nuclear Industry: Steam generator tubing and heat exchangers in nuclear power systems.
- Industrial Heating: Heating element sheaths, thermowells, and other high-temperature furnace components.
Why Choose TOKO TECH’s ALLOY 800 Series Coiled Tubing?
TOKO TECH ensures the highest quality through stringent process control. The manufacturing includes a solution annealing heat treatment at ~1038-1149°C (1900-2100°F) to achieve optimal microstructure and high-temperature performance, followed by 100% non-destructive testing (Eddy Current or Ultrasonic). Given its application in high-temperature environments, coils are typically protected with VCI (Vapor Corrosion Inhibitor) packaging to prevent surface contamination during transit and storage.
In summary, TOKO TECH’s ALLOY 800/H/HT seamless coiled tubing provides robust and reliable solutions for severe high-temperature applications requiring exceptional oxidation, carburization, and corrosion resistance. The specific grade selection (800, 800H, or 800HT) allows engineers to optimize material performance based on exact temperature and mechanical property requirements, making this alloy family indispensable for high-temperature processing equipment across multiple industries.