Alloy 455，Custom 455 Fittings，UNS S45500，EFORU

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

### **Alloy 455 / Custom 455 Fittings (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 ultra-high strength, good corrosion resistance, and excellent toughness. **Custom 455 Fittings** are precision-engineered components designed for high-performance piping and tubing systems where maximum strength, reliability, and corrosion resistance are required in demanding environments. The UNS **S45500** designation identifies this specific precipitation-hardening stainless steel composition. Custom 455 fittings maintain the alloy's characteristic ultra-high strength properties while providing the dimensional precision and reliability required for critical fluid handling systems. --- ### **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 creates a precipitation-hardenable martensitic structure capable of achieving yield strengths exceeding 1450 MPa (210 ksi) after proper heat treatment, while maintaining good corrosion resistance comparable to standard austenitic stainless steels. --- ### **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 fittings after heat treatment: | Condition | Tensile Strength | Yield Strength (0.2% Offset) | Elongation (%) | Hardness (Rockwell C) | | :--- | :--- | :--- | :--- | :--- | | **Solution Treated** | 1000-1200 MPa (145-175 ksi) | 950-1100 MPa (140-160 ksi) | 10-15 | 25-32 | | **H900 Aged** | 1550-1750 MPa (225-255 ksi) | 1450-1650 MPa (210-240 ksi) | 6-10 | 44-48 | | **H1000 Aged** | 1400-1600 MPa (200-230 ksi) | 1300-1500 MPa (190-220 ksi) | 8-12 | 40-44 | | **H1050 Aged** | 1250-1450 MPa (180-210 ksi) | 1150-1350 MPa (170-195 ksi) | 10-14 | 36-40 | --- ### **International Standards** | Standard Organization | Standard Number | Specification | | :--- | :--- | :--- | | **ASTM** | ASTM A182/A182M | Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service | | **ASME** | B16.11 | Forged Fittings, Socket-Welding and Threaded | | **ASME** | SA-182 | Forged or Rolled Alloy-Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service | | **MSS** | SP-43 | Wrought Stainless Steel Fittings | | **UNS** | S45500 | Alloy 455 | | **ASTM** | A965/A965M | Steel Fittings for Pressure Vessels and Components | --- ### **Product Specifications** **Fitting Types Available:** - **Elbows:** 45°, 90°, 180° - **Tees:** Equal and Reducing - **Reducers:** Concentric and Eccentric - **Couplings** - **Unions** - **Caps** - **Bushings** - **Crosses** - **Nipples** **Pressure Ratings:** - Socket-Weld: 2000-6000 PSI - Threaded: 1500-3000 PSI - Buttweld: Schedule 40, 80, 160 **Size Range:** - Socket-Weld: 1/8" to 4" NPS - Threaded: 1/8" to 2" NPS - Buttweld: 1/2" to 24" NPS --- ### **Manufacturing Processes** **Primary Manufacturing Methods:** - Hot forging - Cold forming - Precision machining - Investment casting - Powder metallurgy **Quality Control:** - Dimensional verification - Pressure testing - Material certification - Surface inspection - Non-destructive testing --- ### **Heat Treatment** **Solution Treatment:** - Temperature: 815-830°C (1500-1525°F) - Time: 30 minutes per inch of thickness - 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 & Defense:** - Aircraft hydraulic systems - Missile propulsion systems - Rocket fuel systems - High-pressure air systems - Defense vehicle fluid systems **Oil & Gas Industry:** - High-pressure wellhead components - Chemical injection systems - Subsea applications - Pressure vessel connections - Instrumentation fittings **Chemical Processing:** - High-pressure chemical systems - Corrosive fluid handling - Process instrumentation - Reactor systems - Utility service fittings **Power Generation:** - High-pressure steam systems - Feedwater systems - Hydraulic control systems - Instrumentation fittings - Nuclear applications **Special Applications:** - Cryogenic systems - High-pressure research - Medical gas systems - Semiconductor processing - Special industrial applications --- ### **Installation & Joining** **Welding Procedures:** - **GTAW (TIG):** Preferred method - **GMAW (MIG):** Suitable with proper technique - **Filler Metal:** Custom 455 or similar PH stainless - **Pre-heat:** Generally not required - **Post-weld Heat Treatment:** Required for maximum properties **Threaded Connections:** - Excellent thread strength - Good galling resistance - Suitable for high-pressure applications - Proper thread sealing essential --- ### **Key Advantages** - **Ultra-High Strength:** Maximum strength available in fitting form - **Excellent Pressure Capability:** Suitable for extreme pressure applications - **Good Corrosion Resistance:** Superior to most martensitic stainless steels - **Dimensional Stability:** Minimal distortion during heat treatment - **Temperature Resistance:** Serviceable from cryogenic to 425°C (800°F) - **Reliable Performance:** Proven in critical applications - **Long Service Life:** Excellent fatigue resistance **Design Considerations:** - Maximum service temperature: 425°C (800°F) - Not recommended for prolonged exposure above 425°C - Suitable for cryogenic applications - Good resistance to stress corrosion cracking - Magnetic after heat treatment --- ### **Quality Assurance** **Testing and Certification:** - Hydrostatic testing - Pneumatic testing - Material certification - Dimensional verification - Surface finish inspection - Non-destructive testing **Certification Standards:** - ASTM A182 requirements - ASME Section VIII - PED 2014/68/EU - NACE MR0175 (where applicable) Custom 455 Fittings (UNS S45500) represent a premium precipitation-hardening stainless steel solution for high-performance fluid handling systems. Their superior characteristics make them particularly valuable for aerospace, defense, oil and gas, and power generation applications where maximum strength, pressure resistance, and reliability are critical requirements in the most demanding service environments. The fittings maintain dimensional precision and mechanical integrity even under extreme operating conditions.

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 1697 gallon liquid totes Special package is available on request.