Alloy 455，Custom 455 Other/Similar Specs，UNS S45500，EFORU

British Specs:，American Specs:AMS 5617 Bar and Forgings AMS 5860 Sheet, Strip and Plate，German Specs:

### **Alloy 455 / Custom 455 & Similar Specifications (UNS S45500) - Technical Overview** **Overview** **Alloy 455** (Custom 455) represents a specialized subgroup of martensitic precipitation-hardening stainless steels specifically engineered to provide ultra-high strength combined with good corrosion resistance. While UNS S45500 is the primary specification for this premium precipitation-hardening alloy, several equivalent and similar specifications exist across different international standards and specialized applications. This overview covers the core Custom 455 material along with its various international designations and comparable specifications used in global industry. --- ### **Chemical Composition** The base chemical composition maintains consistency across major specifications: | Element | Content (%) (ASTM A564/AMS 5617) | | :--- | :--- | | **Iron (Fe)** | Balance | | **Chromium (Cr)** | 11.0 - 12.5 | | **Nickel (Ni)** | 7.5 - 9.5 | | **Copper (Cu)** | 1.5 - 2.5 | | **Niobium (Nb)** | 0.1 - 0.5 | | **Titanium (Ti)** | 0.8 - 1.4 | | **Manganese (Mn)** | 0.50 (Max) | | **Silicon (Si)** | 0.50 (Max) | | **Carbon (C)** | 0.05 (Max) | | **Phosphorus (P)** | 0.04 (Max) | | **Sulfur (S)** | 0.03 (Max) | **Note:** The precise balance of chromium, nickel, copper, and titanium/nobium creates the unique precipitation-hardenable martensitic structure capable of achieving the highest strength levels among stainless steels. --- ### **Physical Properties** Consistent physical properties across all Custom 455 specifications: | Property | Value | | :--- | :--- | | **Density** | 7.76 g/cm³ (0.280 lb/in³) | | **Melting Point** | 1400-1440°C (2550-2625°F) | | **Electrical Resistivity** | 85 μΩ·cm at 20°C | | **Thermal Conductivity** | 18.5 W/m·K at 20°C | | **Thermal Expansion Coefficient** | 10.1 μm/m·°C (20-100°C) | | **Magnetic Permeability** | Magnetic after heat treatment | --- ### **Mechanical Properties** Typical mechanical properties for annealed condition across specifications: | Product Form | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (%) | | :--- | :--- | :--- | :--- | | **Bar & Rod** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | | **Sheet & Plate** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | | **Forgings** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | **Aged Condition (H900):** - Tensile Strength: 1550-1750 MPa (225-255 ksi) - Yield Strength: 1450-1650 MPa (210-240 ksi) - Elongation: 6-10% --- ### **International Standards & Cross-References** **Primary U.S. Standards:** - **ASTM A564/A564M** - Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes - **ASTM A693** - Precipitation Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip - **AMS 5617** - Precipitation Hardening Stainless Steel Bars and Forgings - **AMS 5606** - Steel Plate, Corrosion-Resistant, 12Cr - 9Ni - 1.5Cu - 1.0Ti - **ASME SA-564** - Age-Hardening Stainless Steel Bars for Pressure Vessels - **ASME SA-693** - Precipitation Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip **European Equivalents:** - **DIN 1.4594** - X3CrNiCuMoTi17-6-4 - **EN 1.4594** (European Norm) - **BS S129** (British Standard) - **AFNOR Z5CNU17-04** (French Standard) **Other International Standards:** - **JIS SUS 455** (Japanese Standard) - **GB 0Cr17Ni4Cu4Nb** (Chinese Standard) - **ISO 4954** - Tool steels and other alloy steels **Notable Similar Specifications:** - **17-4PH Stainless (UNS S17400)** - Similar but lower strength - **15-5PH Stainless (UNS S15500)** - Improved toughness version - **13-8Mo Stainless (UNS S13800)** - Better corrosion resistance - **Custom 450 (UNS S45000)** - Lower cost alternative - **PH 13-8 Mo (UNS S13800)** - Marine grade alternative --- ### **Product Applications Across Specifications** **Aerospace & Defense (All Standards):** - Aircraft landing gear components - Missile and rocket components - Structural airframe parts - Engine mounts and components - Defense mechanism parts **Oil & Gas Industry:** - Wellhead components - Valve bodies and stems - Drill string components - Pressure vessel parts - Subsea equipment **Medical Devices:** - Surgical instruments - Orthopedic implants - Medical tooling - Dental instruments - Surgical equipment **Industrial Equipment:** - High-strength shafts - Pump components - Valve parts - Machinery components - Tooling applications **Power Generation:** - Turbine components - Generator parts - Nuclear components - Heat exchanger parts - Pump components --- ### **Key Advantages & Selection Considerations** **Universal Advantages:** - **Ultra-High Strength:** Highest strength levels among stainless steels - **Good Corrosion Resistance:** Superior to most martensitic stainless steels - **Excellent Toughness:** Good combination of strength and fracture toughness - **Simple Heat Treatment:** Single-step aging process - **Dimensional Stability:** Minimal distortion during heat treatment **Specification Selection Guidelines:** - **Aerospace Applications:** AMS standards for flight-critical components - **Pressure Vessels:** ASME SA specifications for code compliance - **International Projects:** DIN/EN standards for European markets - **General Applications:** ASTM standards for industrial use - **Medical Applications:** ASTM F standards for medical devices **Comparative Analysis with Similar Alloys:** **vs. 17-4PH (S17400):** - Higher strength and hardness - Better transverse toughness - Improved corrosion resistance - More consistent heat treatment response **vs. 15-5PH (S15500):** - Higher strength capability - Better mechanical properties - Superior fatigue strength - Enhanced corrosion resistance **vs. 13-8Mo (S13800):** - Higher strength levels - Better machinability - Superior fatigue properties - Good stress corrosion resistance --- ### **Heat Treatment Variations** **Standard Heat Treatment:** - Solution Treatment: 815-830°C (1500-1525°F) - Aging Treatments: 480-565°C (900-1050°F) **Alternative Treatments:** - Double Aging: For improved properties - Overaging: For specific applications - Cryogenic Treatment: For dimensional stability --- ### **Quality Assurance & Certification** **Standard Testing Requirements:** - Chemical analysis verification - Mechanical testing certification - Hardness testing - Non-destructive examination - Microstructure examination - Corrosion testing (when specified) **Certification Standards:** - **EN 10204 3.1/3.2:** Material inspection certificates - **ISO 9001:** Quality management systems - **AS9100:** Aerospace quality management - **NADCAP:** Special processes accreditation --- ### **Special Considerations** **Fabrication Notes:** - Best machined in solution-treated condition - Good weldability with proper procedures - Suitable for most forming operations - Responds well to various finishing processes **Service Limitations:** - Maximum service temperature: 425°C (800°F) - Not recommended for prolonged high-temperature exposure - Suitable for cryogenic applications - Good resistance to stress corrosion cracking --- ### **Conclusion** The Custom 455/Alloy 455 family (UNS S45500 and equivalents) represents a premium precipitation-hardening stainless steel system specifically optimized for applications requiring the highest strength levels combined with good corrosion resistance. While maintaining consistent base properties across international standards, the alloy offers unparalleled strength characteristics that make it the material of choice for the most demanding applications in aerospace, defense, medical, and high-performance industrial sectors. Engineers can confidently specify this alloy family knowing that equivalent materials are available globally with consistent performance characteristics supported by comprehensive international standards and extensive industrial experience.

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 1699 gallon liquid totes Special package is available on request.