Cast Stainless Steel Capillary CK20, ASTM A351

Cast Stainless Steel Capillary CK20, ASTM A351 Product Information -:- For detailed product information, please contact sales. -: Cast Stainless Steel Capillary CK20, ASTM A351 Synonyms -:- For detailed product information, please contact sales. -:

Cast Stainless Steel CK20, ASTM A351 Product Information -:- For detailed product information, please contact sales. -: ### **Technical Datasheet: Cast Stainless Steel CK20 (ASTM A351)** #### **1. Product Overview** Cast Stainless Steel CK20 under ASTM A351 specification is a high-carbon austenitic stainless steel designed for superior high-temperature performance. This 25Cr-20Ni alloy offers exceptional oxidation resistance and maintains excellent mechanical properties at temperatures up to 1150°C (2100°F). The elevated carbon content enhances high-temperature strength and creep resistance, making it particularly suitable for the most demanding high-temperature applications in various industrial sectors. **Key Advantages:** - **Exceptional High-Temperature Strength:** Superior mechanical properties maintained at extreme temperatures - **Outstanding Oxidation Resistance:** Excellent scaling resistance in aggressive atmospheres - **Superior Creep Resistance:** Excellent performance under sustained loading at high temperatures - **Enhanced Carburization Resistance:** Good performance in carburizing environments - **Microstructural Stability:** Resists phase transformation and embrittlement during long-term service --- #### **2. International Standard** This product conforms to the latest edition of: - **ASTM A351/A351M:** Standard Specification for Castings, Austenitic, Austenitic-Ferritic (Duplex), for Pressure-Containing Parts Additional applicable standards: - **UNS J94224:** Unified Numbering System designation - **ASME SA351:** ASME Boiler and Pressure Vessel Code equivalent - **ASTM A297/A297M:** Standard Specification for Steel Castings, Iron-Chromium, Iron-Chromium-Nickel, Heat-Resistant - **ISO 11972:** Corrosion-resistant cast steels for general applications --- #### **3. Chemical Composition (Heat Analysis, %)** The chemical composition features high carbon content for enhanced high-temperature strength. | Element | Composition (%) | |---------|-----------------| | Carbon (C) | 0.20-0.40 | | Manganese (Mn) | 2.00 max | | Silicon (Si) | 0.75-1.50 | | Phosphorus (P), max | 0.04 | | Sulfur (S), max | 0.04 | | Chromium (Cr) | 23.0-27.0 | | Nickel (Ni) | 19.0-22.0 | | Iron (Fe) | Balance | *Note: The high carbon content combined with chromium and nickel provides superior high-temperature strength and oxidation resistance for pressure-containing applications.* --- #### **4. Mechanical Properties** Mechanical properties meet ASTM A351 requirements for high-temperature pressure-containing parts. **Minimum Required Values (Solution Annealed Condition):** - **Tensile Strength:** 485 MPa (70 ksi) min - **Yield Strength (0.2% Offset):** 205 MPa (30 ksi) min - **Elongation in 2" (50 mm):** 25.0% min **Elevated Temperature Properties (Typical):** - **At 870°C (1600°F):** Tensile Strength: 120-150 MPa (17-22 ksi) - **At 980°C (1800°F):** Tensile Strength: 80-100 MPa (12-14.5 ksi) - **Creep Strength:** Excellent performance up to 1150°C (2100°F) - **Stress Rupture:** Superior resistance under sustained loading --- #### **5. Physical Properties (Typical Values)** - **Density:** 7.92 g/cm³ (0.286 lb/in³) - **Modulus of Elasticity:** 200 GPa (29,000 ksi) at 21°C - **Poisson's Ratio:** 0.28 - **Thermal Conductivity:** 14.2 W/m·K (at 100°C) - **Specific Heat Capacity:** 510 J/kg·K (at 0-100°C) - **Coefficient of Thermal Expansion:** 15.8 × 10⁻⁶/°C (20-100°C) - **Electrical Resistivity:** 0.90 μΩ·m - **Magnetic Permeability:** Essentially non-magnetic --- #### **6. Heat Treatment** **Solution Annealing Treatment:** - **Temperature Range:** 1145-1205°C (2095-2200°F) - **Soak Time:** 1-2 hours per inch of thickness, minimum 1 hour - **Cooling Method:** Rapid water quench - **Objective:** To dissolve carbides and achieve homogeneous austenitic structure **Stabilization Treatment (Optional):** - **Temperature:** 870-925°C (1600-1700°F) - **Purpose:** To enhance dimensional stability for high-temperature service --- #### **7. High-Temperature Performance** CK20 demonstrates exceptional performance in severe high-temperature pressure applications: - **Oxidation Resistance:** Outstanding scaling resistance up to 1150°C (2100°F) - **Creep Strength:** Superior resistance to deformation under prolonged stress - **Thermal Fatigue:** Excellent performance under thermal cycling conditions - **Carburization Resistance:** Good performance in carburizing atmospheres - **Structural Stability:** Excellent resistance to sigma phase formation - **Pressure Containment:** Reliable performance under combined thermal and mechanical stresses --- #### **8. Product Applications** CK20 cast stainless steel is extensively used in the most demanding high-temperature pressure applications: **Petrochemical Industry:** - Ethylene cracking furnace tubes - Reform furnace components - Pyrolysis furnace parts - High-temperature reactors **Heat Treatment Industry:** - Radiant tubes and retorts - Heat treatment fixtures - Carburizing equipment - Annealing furnace components **Power Generation:** - Superheater components - High-temperature headers - Boiler parts - Heat exchanger components **Other Applications:** - Chemical processing equipment - Incinerator components - Thermal oxidizer systems - High-temperature valve bodies --- #### **9. Fabrication & Welding Characteristics** **Casting Characteristics:** - Good castability with proper foundry practices - Pattern shrinkage: 25-30 mm/m - Requires adequate feeding for sound pressure-containing castings - Suitable for complex high-temperature components **Machining:** - Moderate machinability in annealed condition - Work hardens during machining operations - Use carbide tools with positive rake geometry - Recommended cutting speeds: 15-20 m/min (50-65 SFM) **Welding:** - **Weldability:** Good with proper procedures - **Preheating:** 150-200°C (300-400°F) recommended - **Interpass Temperature:** 200-250°C (400-480°F) - **Filler Metals:** ENiCrFe-3 or equivalent nickel-base alloys - **Post-weld Heat Treatment:** Full solution annealing recommended --- #### **10. Quality Assurance & Testing** - **Chemical Analysis:** Per ASTM A751 requirements - **Mechanical Testing:** Tensile tests per ASTM A370 from cast-on coupons - **Hardness Testing:** Multiple location verification - **Non-Destructive Testing:** - Radiographic examination per ASTM E94 - Liquid penetrant examination per ASTM E165 - **High-Temperature Testing:** - Creep and stress rupture testing - Oxidation resistance evaluation - **Pressure Testing:** Hydrostatic testing as required - **Certification:** Full traceability with comprehensive mill test certificates --- **Disclaimer:** This technical datasheet provides general information for reference purposes only. CK20 stainless steel under ASTM A351 is specifically designed for high-temperature pressure-containing applications and requires careful consideration of service conditions. Always consult the complete ASTM A351 standard and work with qualified materials engineers for critical applications. The material's performance may be affected by specific operating conditions, and proper design considerations for thermal expansion, creep, and pressure containment are essential for successful long-term performance in elevated temperature service. -:- For detailed product information, please contact sales. -: Cast Stainless Steel CK20, ASTM A351 Specification Dimensions Size： Diameter 20-1000 mm Length <4206 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. -: Cast Stainless Steel CK20, ASTM A351 Properties -:- For detailed product information, please contact sales. -:

Applications of Cast Stainless Steel Capillary CK20, ASTM A351 -:- For detailed product information, please contact sales. -: Chemical Identifiers Cast Stainless Steel Capillary CK20, ASTM A351 -:- For detailed product information, please contact sales. -:

Packing of Cast Stainless Steel Capillary CK20, ASTM A351 -:- 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 Capillary 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 677 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