21Cr-32Ni-Ti-Al Iron Tube,Pipe BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS Tube,PipeS (NCF 800H TB)

21Cr-32Ni-Ti-Al Iron Tube BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) Product Information -:- For detailed product information, please contact sales. -: 21Cr-32Ni-Ti-Al Iron Tube BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) Synonyms -:- For detailed product information, please contact sales. -:

21Cr-32Ni-Ti-Al IRON BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) Product Information -:- For detailed product information, please contact sales. -: **Product Introduction: NCF 800H TB (UNS N08810/N08811) Iron-Based Superalloy for High-Temperature Service** --- ### **1. Overview** **21Cr-32Ni-Ti-Al Alloy (NCF 800H TB)** is an advanced **iron-nickel-chromium superalloy** designed for exceptional long-term performance in extreme thermal environments. Optimized specifically for **seamless tubes** in high-temperature heat exchangers, reformers, and furnaces, this alloy combines outstanding resistance to oxidation, carburization, and sulfidation with superior creep and rupture strength. The "H" designation indicates a controlled carbon content at the upper end of the range and a solution annealing treatment to develop an optimized grain size for high-temperature creep resistance. It is a premier material for service in the **540°C to 870°C (1000°F to 1600°F)** range, where standard stainless steels fail. --- ### **2. International Standards** This alloy is covered by several key international standards for seamless tubes and plates. * **Primary Tube Standards:** * **ASTM B407 / ASME SB-407:** *Standard Specification for Nickel-Iron-Chromium Alloy Seamless Pipe and Tube.* This is the primary specification for tubular products (UNS N08800/N08810/N08811). * **JIS G3463 TUH 1 / NCF 800H TB:** Japanese Industrial Standard for nickel-chromium-iron alloy heat exchanger and condenser tubes. * **DIN 17742 NiCr21Fe (1.4876):** German designation for comparable wrought material. * **Material Designations & Key Equivalents:** * **UNS N08810:** Unified Numbering System designation for the high-carbon (0.05-0.10% C), solution-annealed grade optimized for creep resistance (**800H**). * **UNS N08811:** A variant with tighter control over aluminum and titanium for nuclear applications. * **EN 10095 X8NiCrAlTi32-21 (1.4958):** European standard designation. * **Alloy 800H / 800HT:** Common trade names. **800HT** includes tighter Al+Ti control for improved high-temperature strength. * **Related Product Forms:** Plates and sheets are covered under **ASTM B409 / SB-409**. --- ### **3. Chemical Composition (Weight %, per ASTM B407 for UNS N08810)** The precise balance of solid-solution strengtheners and precipitation formers is critical. | Element | Composition (%) (Typical for 800H) | Role & Benefit | | :--- | :--- | :--- | | **Nickel (Ni)** | 30.0 – 35.0 | **Primary base element.** Stabilizes the austenitic (FCC) structure, provides inherent corrosion resistance, and is key for carburization resistance. | | **Chromium (Cr)** | 19.0 – 23.0 | **Primary alloy.** Confers **exceptional oxidation and sulfidation resistance** at high temperatures. | | **Iron (Fe)** | Balance (~39.5 – 45.5) | Forms the base of the alloy matrix. | | **Carbon (C)** | 0.05 – 0.10 | **Deliberately elevated (vs. 800).** Forms stable carbides (e.g., TiC) that strengthen grain boundaries, enhancing **long-term creep strength**. | | **Aluminum (Al)** | 0.15 – 0.60 | Combines with titanium to form the strengthening **gamma-prime (γ') phase [Ni₃(Al,Ti)]** during service, providing precipitation hardening at high temperatures. | | **Titanium (Ti)** | 0.15 – 0.60 | Works synergistically with Al for γ' formation; also ties up carbon as stable TiC. | | **Manganese (Mn)** | ≤ 1.50 | Aids in hot workability and sulfur control. | | **Silicon (Si)** | ≤ 1.00 | Enhances oxidation resistance. | | **Copper (Cu)** | ≤ 0.75 | Residual, can improve certain corrosion aspects. | | **Sulfur (S)** | ≤ 0.015 | Impurity, kept very low for hot workability and weldability. | --- ### **4. Typical Physical & Mechanical Properties (For Seamless Tube, Solution Annealed)** * **Solution Annealing:** Typically performed at ~1120-1170°C (2050-2140°F) followed by rapid cooling to develop the coarse grain structure essential for creep resistance in 800H. * **Tensile Strength (Room Temp):** ≥ 450 MPa (65,000 psi) * **Yield Strength (0.2% Offset, RT):** ≥ 170 MPa (25,000 psi) * **Elongation (% in 50mm):** ≥ 30% * **Density:** 7.94 g/cm³ * **Melting Range:** ~ 1350 – 1400 °C (2460 – 2550 °F) * **Modulus of Elasticity:** ~ 200 GPa (29 x 10⁶ psi) at 21°C; decreases gradually with temperature. * **Thermal Conductivity:** ~ 12 W/m·K (at 100°C) – *Relatively low, typical of austenitic alloys.* * **Coefficient of Thermal Expansion:** ~ 14.5 x 10⁻⁶ /K (20-100°C) – *Higher than ferritic steels; thermal management is critical in design.* * **Key High-Temperature Performance:** * **Oxidation/Carburization Resistance:** Excellent up to **~1100°C (2012°F)**. The high Ni content resists carburization; high Cr forms a protective oxide scale. * **Creep & Stress-Rupture Strength:** Outstanding, especially in the **600-900°C** range. The coarse grain structure of 800H is optimized for this. * **Sulfidation Resistance:** Good, superior to many stainless steels due to high Ni content. --- ### **5. Product Application** NCF 800H TB tubes are the material of choice for the hottest and most aggressive process environments. * **Petrochemical & Chemical Processing:** * **Steam Methane Reformer (SMR) Tubes:** The **flagship application**. Used in the radiant and convection sections for hydrogen production. * **Ethylene Cracker Tubes:** For pyrolysis furnaces. * **Heater Tubes & Coils** in direct-fired heaters for high-temperature processes. * **Power Generation:** * **Advanced Nuclear Reactors:** For heat exchanger and steam generator tubing (specifically UNS N08811). * **Heat Recovery Steam Generators (HRSG)** in high-temperature sections. * **Industrial Furnaces:** For radiant tubes, muffles, and retorts. * **Heat Exchangers:** For severe service involving high-temperature, high-pressure gases. --- ### **6. Key Features & Advantages** * **Exceptional High-Temperature Strength & Stability:** Unmatched creep and rupture life in the 650-900°C range among Fe-Ni-Cr alloys. * **Superior Resistance to Environmental Attack:** Outstanding performance against oxidation, carburization, and nitriding in complex process atmospheres. * **Good Metallurgical Stability:** Resists sigma phase and other detrimental precipitate formation during long-term exposure. * **Fabricability:** Can be welded (using alloy 625/82/182 filler) and formed using standard techniques for austenitic alloys, though its high strength at temperature requires more power. * **Code Recognition:** Fully approved in ASME Boiler and Pressure Vessel Code, Section I & VIII, with published design stress values up to 815°C (1500°F). --- **In summary, the 21Cr-32Ni-Ti-Al alloy (NCF 800H TB / Alloy 800H) is a premium iron-based superalloy for seamless tubes, engineered to withstand the combined assaults of extreme temperature, high pressure, and corrosive atmospheres. Its optimized composition and structure make it indispensable for critical tubular components in steam reforming, ethylene cracking, and other high-value thermal processes where reliability over decades is paramount.** -:- For detailed product information, please contact sales. -: 21Cr-32Ni-Ti-Al IRON BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) Specification Dimensions Size： Diameter 20-1000 mm Length <7017 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: 21Cr-32Ni-Ti-Al IRON BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) Properties -:- For detailed product information, please contact sales. -:

Applications of 21Cr-32Ni-Ti-Al Iron Tube BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) -:- For detailed product information, please contact sales. -: Chemical Identifiers 21Cr-32Ni-Ti-Al Iron Tube BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) -:- For detailed product information, please contact sales. -:

Packing of 21Cr-32Ni-Ti-Al Iron Tube BASED 21Cr-32Ni-Ti-Al ALLOY FOR HEAT EXCHANGER SEAMLESS TUBES (NCF 800H TB) -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Tube drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3488 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition