Alloy 455,Custom 455,UNS S45500,EFORU

**Product Data Sheet: Alloy 455 / Custom 455 (UNS S45500)** 

 **1. Overview** Alloy 455, commercially known as Custom 455, is a martensitic precipitation-hardening stainless steel designed to provide an exceptional combination of high strength, good toughness, and excellent corrosion resistance. This alloy can be heat treated to achieve tensile strengths exceeding 1550 MPa (225 ksi) while maintaining useful ductility and corrosion resistance superior to that of many other martensitic stainless steels. It is particularly valued in aerospace and high-performance applications where weight savings and reliability are critical. 

 **2. International Standards** 

- **ASTM Standards**: A564/A564M (Hot Rolled & Cold Finished Bar), A693 (Precipitation Hardening Stainless Steel) 

- **AMS Standards**: AMS 5617 (Bar, Wire, Forgings), AMS 5864 (Wire) 

- **UNS Designation**: S45500 

- **Other Specifications**: QQ-S-763, MIL-S-23413 

 **3. Chemical Composition (wt%)** 

| Element        | Min.   | Max.   | 

|----------------|--------|--------| 

| Iron (Fe)      | Balance| Balance| 

| Chromium (Cr)  | 11.0   | 12.5   | 

| Nickel (Ni)    | 7.5    | 9.5    | 

| Copper (Cu)    | 1.5    | 2.5    | 

| Titanium (Ti)  | 0.8    | 1.4    | 

| Niobium (Nb)   | 0.1    | 0.5    | 

| Manganese (Mn) | -      | 0.5    | 

| Silicon (Si)   | -      | 0.5    | 

| Carbon (C)     | -      | 0.05   | 

| Phosphorus (P) | -      | 0.04   | 

| Sulfur (S)     | -      | 0.03   | 

 **4. Physical Properties**

 | Property                      | Value                           | 

|-------------------------------|---------------------------------| 

| Density                       | 7.81 g/cm³ (0.282 lb/in³)      | 

| Melting Point                 | 1400-1440°C (2550-2625°F)      | 

| Thermal Conductivity          | 19.0 W/m·K (at 100°C)          | 

| Electrical Resistivity        | 0.85 μΩ·m (at 20°C)            | 

| Coefficient of Thermal Expansion | 10.1 μm/m·°C (20-100°C)    | 

| Magnetic Permeability         | Magnetic in all conditions     | 

 **5. Mechanical Properties (Typical After H900 Aging)** 

| Property                      | Value                           | 

|-------------------------------|---------------------------------| 

| Tensile Strength              | 1550-1690 MPa (225-245 ksi)     | 

| Yield Strength (0.2% Offset)  | 1450-1620 MPa (210-235 ksi)     | 

| Elongation (in 50 mm)         | 8-12%                          | 

| Reduction in Area             | 35-50%                         | 

| Hardness (Rockwell C)         | 44-48 HRC                       | 

 **6. Heat Treatment Conditions** 

- **Solution Treatment**: 820-870°C (1500-1600°F) + rapid cool 

- **Aging Treatments**:  - H900: 480°C (900°F) for 4 hours 

- Peak strength  - H1000: 510°C (950°F) for 4 hours - Balanced properties  

- H1050: 565°C (1050°F) for 4 hours - High toughness 

 **7. Product Forms** 

- Round Bar, Flat Bar, and Forging Stock 

- Wire and Strip 

- Forgings and Billets 

- Fasteners and Machined Components 

 **8. Applications** 

- **Aerospace**: Landing gear components, actuator systems, fasteners 

- **Defense**: Missile components, helicopter parts, firearm actions 

- **Medical**: Surgical instruments, dental equipment 

- **Industrial**: High-strength shafts, valves, springs 

- **Marine**: Fasteners and fittings for marine environments 

 **9. Corrosion Resistance** 

- Excellent resistance to atmospheric corrosion and fresh water 

- Good resistance to mild acids and alkaline solutions 

- Superior to conventional hardenable stainless steels (e.g., 410, 420) 

- Not recommended for severe corrosive environments like marine splash zones 

 **10. Fabrication Notes** 

- **Machining**: Best performed in annealed condition; use positive rake tools 

- **Welding**: Weldable by all standard methods; post-weld heat treatment required 

- **Forming**: Good formability in solution annealed condition 

- **Heat Treatment**: Requires precise temperature control for optimal properties 

 **11. Key Advantages** 

- Ultra-high strength-to-weight ratio 

- Good transverse toughness compared to other PH steels 

- Excellent fatigue strength and stress corrosion resistance 

- Minimal distortion during heat treatment

Packing of Alloy 455,Custom 455,UNS S45500

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 1629 gallon liquid totes Special package is available on request.