Alloy 20 / 020，Carpenter 20Cb-3 Other/Similar Specs，UNS N08020,E FORU

British Specs:，American Specs:，German Specs: WS 2.4660

**Product Name:** Alloy 20 / Carpenter 20Cb-3® & Related Specifications | UNS N08020 **Material Type:** Nickel-Iron-Chromium Austenitic Stainless Steel Family **Standard:** ASTM B463, B464, B462, B473, B729 | ASME SB463, SB464, SB462 --- ### **Overview** Alloy 20 (UNS N08020), commercially known as **Carpenter 20Cb-3®**, represents a family of nickel-iron-chromium austenitic stainless steels specifically developed for superior resistance to sulfuric acid corrosion. This comprehensive material system includes various product forms and specifications designed to meet diverse application requirements while maintaining consistent chemical composition and corrosion resistance properties across all product forms. --- ### **Material Family Characteristics** - **Sulfuric Acid Optimization:** Specifically designed for sulfuric acid service - **Multi-Product Availability:** Available in all standard industrial forms - **Consistent Performance:** Uniform properties across all product types - **International Recognition:** Widely accepted in global standards - **Proven Reliability:** Decades of successful industrial application --- ### **Chemical Composition (Typical Weight %)** | Element | Content (%) | Element | Content (%) | |---------|-------------|---------|-------------| | Nickel (Ni) | 32.0-38.0 | Chromium (Cr) | 19.0-21.0 | | Iron (Fe) | Balance | Molybdenum (Mo) | 2.0-3.0 | | Copper (Cu) | 3.0-4.0 | Manganese (Mn) | ≤2.0 | | Silicon (Si) | ≤1.0 | Carbon (C) | ≤0.07 | | Niobium (Nb) | 8×C-1.0 | Phosphorus (P) | ≤0.045 | | Sulfur (S) | ≤0.035 | | | --- ### **Physical & Mechanical Properties** #### **Physical Properties** - **Density:** 8.08 g/cm³ (0.292 lb/in³) - **Melting Range:** 1440-1500°C (2620-2730°F) - **Thermal Expansion Coefficient:** 15.9 × 10⁻⁶/°C (20-100°C) - **Modulus of Elasticity:** 186 GPa (27 × 10⁶ psi) - **Thermal Conductivity:** 12.9 W/m·K at 100°C - **Electrical Resistivity:** 0.90 μΩ·m at 20°C #### **Mechanical Properties (Annealed Condition)** | Property | Typical Range | |----------|---------------| | Tensile Strength | 620-690 MPa (90-100 ksi) | | Yield Strength (0.2% Offset) | 300-415 MPa (44-60 ksi) | | Elongation | 30-50% | | Hardness | 150-190 HB | | Reduction of Area | 50-70% | --- ### **Product Forms & Specifications** #### **Complete Product Range** - **Plate & Sheet:** ASTM B463 / ASME SB463 - **Pipe & Tube:** ASTM B464, B729 / ASME SB464 - **Bar & Wire:** ASTM B473 / ASME SB473 - **Forgings:** ASTM B462 / ASME SB462 - **Fittings:** ASTM B366 / ASME SB366 - **Fasteners:** ASTM A193 / ASME SA193 #### **Special Conditions** - Solution Annealed - Cold Worked - Stress Relieved - Q&T (Quenched and Tempered) for specific applications --- ### **International Standards & Equivalents** #### **Global Standards** - **UNS:** N08020 - **ASTM/ASME:** Full range of B/SB specifications - **EN:** 1.4596 (X3CrNiMoCuNb16-5-1) - **ISO:** 15156-3 (NACE MR0175) - **JIS:** NCF 825 - **GOST:** 20Ch23N18 #### **Proprietary Designations** - **Carpenter 20Cb-3®** - **ATI 20®** - **NAS 125N** - **Werkstoff Nr.:** 2.4660 --- ### **Applications by Industry** #### **Chemical Processing** - Sulfuric acid production and handling - Phosphoric acid equipment - Chemical reactors and vessels - Heat exchangers and condensers - Piping systems and storage tanks #### **Pharmaceutical** - Reactor vessels - Mixing equipment - Process piping - Storage and handling systems #### **Food Processing** - Vinegar production - Food acid handling - Processing equipment - Storage vessels #### **Oil & Gas** - Sour service applications - Process piping - Valve components - Heat exchanger tubing #### **Industrial Applications** - Pollution control equipment - Waste treatment systems - Industrial heating systems - Process cooling systems --- ### **Corrosion Resistance Profile** #### **Excellent Resistance** - Sulfuric acid (all concentrations to 95°C) - Phosphoric acid - Nitric acid - Organic acids - Chloride stress corrosion cracking #### **Good Resistance** - Mixed acid environments - Acidic salt solutions - Oxidizing chemicals - Industrial atmospheres #### **Limited Resistance** - Hydrochloric acid - Hydrofluoric acid - Strong alkalis - Oxidizing chlorides --- ### **Fabrication Characteristics** #### **Welding** - **Compatible Processes:** GTAW, GMAW, SMAW, SAW - **Filler Metals:** Alloy 20, ENiCrFe-11, ENiCrFe-2 - **Precautions:** Standard stainless steel practices apply #### **Machining** - **Machinability:** 40-50% of B1112 steel - **Tooling:** Positive rake angles recommended - **Coolant:** Essential for optimal results #### **Forming** - **Cold Working:** Excellent capabilities - **Hot Working:** 1150-1250°C (2100-2280°F) - **Annealing:** 925-1010°C (1700-1850°F) --- ### **Quality Assurance & Certification** #### **Testing Requirements** - Chemical analysis - Mechanical testing - Corrosion testing - Non-destructive examination - Dimensional verification #### **Certifications** - NACE MR0175/ISO 15156 - PED 2014/68/EU - ASME Boiler and Pressure Vessel Code - ISO 9001 Quality Management --- ### **Technical Support Services** #### **Engineering Support** - Material selection assistance - Fabrication process optimization - Failure analysis - Application engineering - Technical consultation #### **Custom Solutions** - Special heat treatments - Custom compositions - Unique product forms - Application-specific testing --- ### **Conclusion** The Alloy 20/Carpenter 20Cb-3® material system represents a comprehensive family of nickel-iron-chromium austenitic stainless steels specifically engineered for superior performance in sulfuric acid and other aggressive chemical environments. With consistent chemical composition and mechanical properties across all product forms, this alloy family provides reliable, cost-effective solutions for a wide range of industrial applications. The extensive international standardization and proven track record make it the material of choice for engineers and designers seeking long-term reliability in corrosive service conditions. --- *Carpenter 20Cb-3® is a registered trademark of Carpenter Technology Corporation. All technical data are typical values and should be verified for specific applications. Consult manufacturer's specifications for project-specific requirements and applicable codes and standards.*

Packing of Standard Packing: 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 2674 gallon liquid totes Special package is available on request.