Alloy 455，Custom 455 ，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) - Product Introduction** **Overview** **Alloy 455**, commercially known as **Custom 455**, is a premium martensitic precipitation-hardening stainless steel that offers an exceptional combination of high strength, good corrosion resistance, and excellent toughness. This alloy is specifically designed to provide maximum strength and hardness while maintaining good corrosion resistance comparable to standard austenitic stainless steels. Custom 455 is particularly valued for applications requiring high strength-to-weight ratios and reliability in demanding environments. The UNS **S45500** designation identifies this specific precipitation-hardening stainless steel composition. The alloy achieves its superior mechanical properties through a simple heat treatment process, making it suitable for complex components that require dimensional stability during heat treatment. --- ### **Chemical Composition** | Element | Content (%) | | :--- | :--- | | **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) | **Key Feature:** The balanced composition of chromium, nickel, copper, and titanium/nobium creates a precipitation-hardenable martensitic structure capable of achieving very high strength levels while maintaining good corrosion resistance. --- ### **Physical Properties** | 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 Custom 455 after heat treatment: | Condition | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (%) | Hardness (Rockwell) | | :--- | :--- | :--- | :--- | :--- | | **Annealed** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | C25-32 | | **H900** | 1550-1750 MPa (225-255 ksi) | 1450-1650 MPa (210-240 ksi) | 6-10 | C44-48 | | **H1000** | 1400-1600 MPa (200-230 ksi) | 1300-1500 MPa (190-220 ksi) | 8-12 | C40-44 | | **H1050** | 1250-1450 MPa (180-210 ksi) | 1150-1350 MPa (170-195 ksi) | 10-14 | C36-40 | --- ### **International Standards** | Standard Organization | Standard Number | Specification | | :--- | :--- | :--- | | **ASTM** | ASTM A564/A564M | Standard Specification for Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes | | **AMS** | AMS 5617 | Precipitation Hardening Stainless Steel Bars and Forgings | | **ASME** | SA-564 | Age-Hardening Stainless Steel Bars for Pressure Vessels | | **UNS** | S45500 | Alloy 455 | | **AMS** | AMS 5864 | Welding Wire | | **ASTM** | ASTM A693 | Precipitation Hardening Stainless and Heat-Resisting Steel Plate, Sheet, and Strip | --- ### **Heat Treatment** **Solution Treatment:** - Temperature: 815-830°C (1500-1525°F) - Cooling: Air cool or faster - Result: Soft condition for machining **Aging Treatments:** - **H900:** 480°C (900°F) for 4 hours, air cool - **H950:** 510°C (950°F) for 4 hours, air cool - **H1000:** 540°C (1000°F) for 4 hours, air cool - **H1050:** 565°C (1050°F) for 4 hours, air cool --- ### **Product Applications** **Aerospace Industry:** - Aircraft landing gear components - Missile and rocket components - Structural airframe parts - Fasteners and high-strength bolts - Engine mounts and components **Defense Applications:** - Firearm components - Armor systems - Military vehicle parts - Weapon system components - Defense mechanism parts **Industrial Equipment:** - High-strength shafts - Pump components - Valve parts - Machinery components - Tooling applications **Marine Applications:** - Marine shafting - Submarine components - Naval vessel parts - Offshore equipment - Marine hardware **Medical Devices:** - Surgical instruments - Orthopedic implants - Medical tooling - Dental instruments - Surgical equipment --- ### **Key Advantages** - **Ultra-High Strength:** Capable of achieving yield strengths over 1450 MPa (210 ksi) - **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 after solution treatment - **Dimensional Stability:** Minimal distortion during heat treatment - **Good Fabricability:** Can be machined and formed in annealed condition - **High Strength-to-Weight Ratio:** Ideal for weight-critical applications **Processing Characteristics:** **Machinability:** - Best machined in solution-treated condition - Similar to other precipitation-hardening stainless steels - Requires rigid setups and positive rake tools - Recommended machining rating: 45% (compared to 1212 steel) **Welding:** - Good weldability using matching filler metal - Post-weld heat treatment required for maximum properties - Gas tungsten arc welding (GTAW) preferred - Can be welded in solution-treated condition --- ### **Corrosion Resistance** Custom 455 offers good corrosion resistance in various environments: - Excellent resistance to atmospheric corrosion - Good resistance to fresh and salt water - Moderate resistance to acids and chemicals - Superior to 400-series martensitic stainless steels - Comparable to Type 304 in many environments --- ### **Quality Assurance** **Testing and Certification:** - Chemical analysis certification - Mechanical testing at room temperature - Hardness testing - Non-destructive testing (as required) - Microstructure examination - Corrosion testing (upon request) Alloy 455 / Custom 455 (UNS S45500) represents a premium precipitation-hardening stainless steel that provides an outstanding combination of ultra-high strength, good corrosion resistance, and excellent mechanical properties. Its simple heat treatment process and reliable performance make it particularly valuable for aerospace, defense, marine, and medical applications where maximum strength and reliability are critical requirements.

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 1689 gallon liquid totes Special package is available on request.