Alloy 455，Custom 455 Wire，UNS S45500，EFORU

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

### **Alloy 455 / Custom 455 / UNS S45500 - Premium Precipitation-Hardenable Stainless Steel Wire** **Introduction** Alloy 455, also known commercially as Custom 455 and standardized as UNS S45500, is a high-strength, precipitation-hardenable (PH) martensitic stainless steel. It is renowned for achieving an exceptional combination of high tensile strength, good toughness, and excellent corrosion resistance, rivaling that of Type 304 stainless steel in many environments. Its key advantage lies in its simple, low-temperature heat treatment, which results in minimal distortion and scaling, making it an ideal choice for precision components, particularly in wire form. This alloy is supplied in the solution-treated condition (Condition A) and can be hardened to various strength levels through a single aging treatment. **Chemical Composition (ASTM A564 / AMS 5617)** The composition is precisely balanced to form a martensitic structure upon cooling and to develop precipitates during aging for strengthening. | Element | Content (%) | | :--- | :--- | | **Iron (Fe)** | Balance | | **Chromium (Cr)** | 11.00 - 12.50 | | **Nickel (Ni)** | 7.50 - 9.50 | | **Copper (Cu)** | 1.50 - 2.50 | | **Niobium (Nb) + Tantalum (Ta)** | 0.10 - 0.50 | | **Titanium (Ti)** | 0.80 - 1.40 | | **Carbon (C)** | 0.05 max | | **Manganese (Mn)** | 0.50 max | | **Silicon (Si)** | 0.50 max | | **Phosphorus (P)** | 0.040 max | | **Sulfur (S)** | 0.030 max | *The primary strengthening mechanism is the precipitation of Niobium and Copper-rich phases within the martensitic matrix during the aging process.* **Physical Properties** | Property | Value | | :--- | :--- | | **Density** | 7.76 g/cm³ (0.280 lb/in³) | | **Melting Point** | ~ 1427°C (2600°F) | | **Electrical Resistivity** | ~ 77.0 μΩ·cm (aged at 510°C / 950°F) | | **Thermal Conductivity** | ~ 17.6 W/m·K (aged at 510°C / 950°F) | | **Magnetic Response** | Magnetic (in all conditions) | **Mechanical Properties (Typical for Wire - H900 Condition)** *Condition H900: Aged at 900°F (482°C) for 4 hours, air cool.* | Property | Value | | :--- | :--- | | **Tensile Strength** | 1620 - 1790 MPa (235 - 260 ksi) | | **Yield Strength (0.2% Offset)** | 1520 - 1655 MPa (220 - 240 ksi) | | **Elongation (in 2 inches / 50mm)** | 6 - 10% | | **Reduction of Area** | 35 - 45% | | **Hardness (Rockwell C)** | 44 - 48 HRC | **Key Characteristics & Advantages** 1. **High Strength-to-Weight Ratio:** Offers strength levels comparable to many high-strength steels but with lower density. 2. **Excellent Corrosion Resistance:** Provides resistance to atmospheric corrosion, fresh water, seawater, and many chemical environments, significantly superior to 17-4PH stainless steel in many cases. 3. **Simple Heat Treatment:** Hardening is achieved through a single, low-temperature aging treatment, minimizing part distortion and eliminating the need for a quenching step. 4. **Good Fabricability:** Can be readily machined, formed, and welded in the solution-annealed condition. Post-weld aging restores strength in the heat-affected zone. 5. **High Toughness:** Maintains good toughness and ductility even at very high strength levels. **Product Applications** Custom 455 wire is specified for high-performance applications across various industries: * **Aerospace:** Critical fasteners, bolts, studs, clevis pins, bellcranks, and landing gear components. * **Medical:** Surgical instruments, orthopedic components, and dental tools requiring high strength, corrosion resistance, and non-magnetic properties (in specific conditions). * **Oil & Gas:** Valve components, springs, and downhole tooling. * **Industrial:** High-performance springs, wire forms, and fasteners used in corrosive environments. * **Marine:** Components exposed to saltwater atmospheres. **International Standards** Alloy 455 / UNS S45500 is covered by several international standards for bar, wire, and forgings. | Standard Type | Standard Number | Title (or Form) | | :--- | :--- | :--- | | **UNS** | **S45500** | Unified Numbering System | | **ASTM** | A564 / A564M | Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes (Grade 455) | | **ASTM** | A693 | Standard Specification for Precipitation-Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip (Grade 455) | | **AMS** | 5617 | Aerospace Material Specification - Steel, Corrosion and Heat Resistant, Wire 11.5Cr - 8.5Ni - 2.2Cu - 1.2Ti (Custom 455) Solution Treated | | **AMS** | 5862 | Aerospace Material Specification - Steel, Welding Wire 11.5Cr - 8.5Ni - 2.2Cu - 1.2Ti (Custom 455) | | **ISO/DIN** | - | While not as commonly standardized as 17-4PH, it is often supplied to customer-specific requirements based on ASTM or AMS specifications. | **Conclusion** Alloy 455 (Custom 455 Wire, UNS S45500) is a premium precipitation-hardening stainless steel that delivers an outstanding balance of ultra-high strength, good ductility, and excellent corrosion resistance. Its simple heat treatment process makes it a cost-effective and reliable choice for manufacturing critical, high-stress components in the aerospace, medical, and energy sectors where performance and reliability are paramount. ---

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 1701 gallon liquid totes Special package is available on request.