25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES

25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES Product Information -:- For detailed product information, please contact sales. -: 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES Synonyms -:- For detailed product information, please contact sales. -:

25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: 25Cr-10Ni-7.5W-B Cobalt-Based Superalloy Castings for Gas Turbine Nozzle Vanes** ## **1. Overview** **25Cr-10Ni-7.5W-B** is a **high-chromium, tungsten-strengthened cobalt-based superalloy** specifically engineered for **gas turbine nozzle guide vanes and other static hot-section components**. This alloy belongs to the **FSX-414 series** of cobalt superalloys, characterized by exceptional **thermal fatigue resistance, hot corrosion resistance, and microstructural stability** at elevated temperatures. The 25% chromium content provides outstanding oxidation and sulfidation resistance in aggressive turbine environments, while the 7.5% tungsten contributes significant solid-solution strengthening. Unlike nickel-based alloys that rely on γ' precipitation hardening, this cobalt alloy derives its high-temperature strength primarily from **carbide reinforcement and solid-solution strengthening**, making it particularly suitable for components subjected to severe thermal cycling and corrosive atmospheres where dimensional stability is paramount. ## **2. International Standards & Specifications** This cobalt superalloy is recognized under several international specifications for high-temperature castings. * **Primary Standards:** * **AMS 5385 / AMS 5386:** Aerospace Material Specifications for cobalt alloy castings, turbine vanes and blades (specifically covers FSX-414 type alloys) * **ASTM A567 / ASME SA567:** Standard Specification for Cobalt-Chromium-Nickel-Tungsten Alloy Castings * **FSX-414:** Original alloy designation from General Electric (GE) development * **International Equivalents:** * **European:** **EN 10095** may include equivalent compositions; **Stellite 31** is a related commercial alloy * **Russian:** **BЖ98 (VZh98)** or similar high-chromium cobalt alloys * **Japanese:** **JIS H5122** (Co-Cr alloys for dental casting) or specialized industrial specifications * **Related Commercial Alloys:** **X-40 (AMS 5384), X-45, Mar-M 509, Haynes 188** (wrought version with similar properties) ## **3. Chemical Composition (Weight %, Typical for FSX-414 Type)** | Element | Typical Range (%) | Role & Benefit | |---------|-------------------|----------------| | **Cobalt (Co)** | Balance (~57-62%) | Matrix former; provides excellent high-temperature strength, thermal fatigue resistance, and carbide stability | | **Chromium (Cr)** | 24.0 – 26.0 | **Primary oxidation/hot-corrosion resistance.** Forms protective Cr₂O₃ scale; provides sulfidation resistance in sulfur-containing environments | | **Nickel (Ni)** | 9.0 – 11.0 | Stabilizes FCC matrix, improves ductility and thermal fatigue resistance | | **Tungsten (W)** | 7.0 – 8.0 | **Primary solid-solution strengthener.** Significantly increases high-temperature strength and creep resistance | | **Carbon (C)** | 0.20 – 0.30 | **Critical for carbide formation.** Forms primary M₆C and M₂₃C₆ carbides that provide dispersion strengthening and grain boundary reinforcement | | **Boron (B)** | 0.010 – 0.020 | **Grain boundary strengthener.** Forms borides that improve creep rupture life and ductility | | **Iron (Fe)** | ≤2.0 | Impurity element, kept low for optimal corrosion resistance | | **Manganese (Mn)** | ≤1.0 | Deoxidizer, improves castability | | **Silicon (Si)** | ≤1.0 | Improves oxidation resistance and fluidity during casting | ## **4. Typical Physical & Mechanical Properties (As Cast + Heat Treated)** * **Processing Condition:** Typically investment cast and given a solution heat treatment at 1230-1260°C (2246-2300°F) followed by aging at 980-1050°C (1796-1922°F) * **Room Temperature Properties:** * **Tensile Strength:** 760 – 860 MPa (110,000 – 125,000 psi) * **Yield Strength (0.2% Offset):** 520 – 620 MPa (75,000 – 90,000 psi) * **Elongation:** 4 – 8% * **Hardness:** 30 – 38 HRC * **Elevated Temperature Performance (980°C / 1796°F):** * **Stress Rupture Life (70 MPa / 10 ksi):** > 500 hours * **Creep Strength (0.2% in 1000h):** > 50 MPa (7,250 psi) * **Thermal Fatigue Resistance:** **Excellent** – superior to most nickel-based alloys in severe thermal cycling applications * **Physical Properties:** * **Density:** 8.6 – 8.8 g/cm³ * **Melting Range:** 1350 – 1400°C (2462 – 2552°F) * **Modulus of Elasticity:** 210 GPa (30.5 × 10⁶ psi) at 20°C * **Thermal Conductivity:** 14 – 17 W/m·K (at 800°C) – Higher than nickel superalloys * **Coefficient of Thermal Expansion:** 13.5 – 14.5 × 10⁻⁶/°C (20–1000°C) ## **5. Product Application** * **Aerospace Gas Turbines:** * **Nozzle Guide Vanes (NGVs)** – Primary application * **Combustor Liners and Flame Holders** * **Turbine Shrouds and Seals** * **Afterburner Components** * **Industrial & Power Generation Gas Turbines:** * **First and Second Stage Nozzle Vanes** * **Transition Pieces and Combustion Chambers** * **Heat Shields and Thermal Barriers** * **Marine & Naval Propulsion:** * **Gas Turbine Externals and Hot Gas Path Components** * **Specialized Applications:** * **Glass Processing Equipment** * **Heat Treatment Fixtures** * **Chemical Processing Components** exposed to high temperatures and corrosion ## **6. Key Features & Advantages** * **Exceptional Thermal Fatigue Resistance:** Superior to nickel-based alloys in applications with severe thermal cycling due to higher thermal conductivity and lower thermal expansion * **Outstanding Hot Corrosion Resistance:** High chromium content (25%) provides excellent resistance to sulfidation and other forms of hot corrosion * **Excellent Microstructural Stability:** Resists γ' coarsening and phase transformation issues common in nickel alloys * **Good Castability:** Produces sound castings with good dimensional accuracy in complex vane geometries * **Weldability and Repairability:** Components can be repaired using cobalt-based filler metals (e.g., Stellite 6, Haynes 188) * **No Precipitation Hardening Required:** Properties developed primarily through solid-solution strengthening and carbide dispersion * **Long-Term Stability:** Maintains properties during extended high-temperature exposure ## **7. Manufacturing & Processing Considerations** * **Casting Method:** **Investment casting** using ceramic molds to produce complex vane geometries with internal cooling passages * **Melting Practice:** Typically **vacuum induction melting (VIM)** to control composition and reduce impurities * **Heat Treatment:** Solution treatment followed by aging to optimize carbide distribution and mechanical properties * **Machining:** Difficult to machine in hardened state; often requires grinding, EDM, or abrasive waterjet cutting * **Joining:** Can be welded using matching or overalloyed cobalt-based filler metals with proper pre-heat and post-weld heat treatment * **Surface Treatment:** Often coated with **thermal barrier coatings (TBCs)** or **aluminide coatings** for enhanced temperature capability * **Quality Control:** Extensive non-destructive testing including X-ray, fluorescent penetrant, and dimensional inspection ## **8. Design Considerations** * **Temperature Capability:** Maximum continuous service temperature of approximately **1050°C (1922°F)** for uncoated components, higher with coatings * **Oxidation Resistance:** Excellent up to 1150°C (2102°F) due to high chromium content * **Thermal Stress Management:** Lower thermal expansion compared to nickel alloys reduces thermal stresses in constrained assemblies * **Corrosion Environment:** Particularly suitable for environments with sulfur, vanadium, or other corrosive contaminants * **Life Expectancy:** Typically designed for 20,000+ hours of operation in industrial turbines * **Cost Considerations:** Higher raw material cost than nickel alloys but often justified by longer service life in specific applications **Summary:** The 25Cr-10Ni-7.5W-B cobalt-based superalloy represents a specialized material solution for gas turbine nozzle vanes operating in severe thermal and corrosive environments. Its unique combination of high chromium content for corrosion resistance, tungsten for strength, and cobalt matrix for thermal fatigue resistance makes it the material of choice for stationary hot-section components where reliability and long-term stability are paramount. The alloy's excellent castability allows for production of complex internally cooled vane designs that optimize turbine efficiency while withstanding the harsh conditions of modern gas turbine operation. -:- For detailed product information, please contact sales. -: 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES Specification Dimensions Size： Diameter 20-1000 mm Length <7024 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. -: 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES Properties -:- For detailed product information, please contact sales. -:

Applications of 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES -:- For detailed product information, please contact sales. -: Chemical Identifiers 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES -:- For detailed product information, please contact sales. -:

Packing of 25Cr-10Ni-7.5W-B COBALT BASED SUPERALLOY CASTINGS FOR GAS TURBINE PARTS, NOZZLE VANES -:- 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 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 3495 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