Multimet N155,Multimet,UNS R30155,E FORU

### **Multimet® N155 / UNS R30155

** **Iron-Nickel-Cobalt-Chromium Superalloy for High-Temperature Service

** --- #### **1. Overview

** **Multimet N155**, also known simply as **Multimet**, is an iron-nickel-cobalt-chromium superalloy designed for high-temperature service up to 980°C (1800°F). This austenitic alloy combines good high-temperature strength with excellent resistance to oxidation and scaling. Developed originally for gas turbine applications, Multimet N155 offers a balanced combination of properties that make it suitable for both elevated temperature and corrosive environment applications. The alloy is strengthened by solid-solution hardening and carbide precipitation, providing reliable performance in demanding conditions. 

 --- #### **2. Chemical Composition (Weight %)

** The typical chemical composition of Multimet N155 is outlined below. 

| Element | Content (%) | Key Function | 

| :--- | :--- | :--- | 

| **Iron (Fe)** | Balance | Base element providing the fundamental matrix. | 

| **Nickel (Ni)** | 19.0 - 22.0 | Stabilizes the austenitic structure and enhances corrosion resistance. | 

| **Cobalt (Co)** | 18.0 - 22.0 | Provides solid-solution strengthening and enhances high-temperature stability. | 

| **Chromium (Cr)** | 20.0 - 22.5 | Imparts oxidation and corrosion resistance through protective oxide formation. | 

| **Tungsten (W)** | 2.0 - 3.0 | Contributes to solid-solution strengthening and creep resistance. | 

| **Molybdenum (Mo)** | 2.5 - 3.5 | Enhances strength and improves resistance to reducing environments. | 

| **Niobium (Nb)** | 0.75 - 1.25 | Forms carbides for secondary strengthening and grain size control. | 

| **Manganese (Mn)** | 1.0 - 2.0 | Improves hot workability and acts as a deoxidizer. | 

| **Silicon (Si)** | 0.50 - 1.00 | Enhances oxidation resistance. | 

| **Carbon (C)** | 0.05 - 0.15 | Forms carbides for grain boundary strengthening. | 

| **Nitrogen (N)** | 0.10 - 0.20 | Enhances strength through solid-solution hardening. | 

| **Phosphorus (P)** | 0.03 max | - | 

| **Sulfur (S)** | 0.03 max | - | 

 --- #### **3. Physical Properties**

| Property | Value / Condition | 

| :--- | :--- | 

| **Density** | 8.23 g/cm³ (0.297 lb/in³) |

| **Melting Range** | ~ 1370 - 1430 °C (2500 - 2610 °F) | 

| **Mean Coefficient of Thermal Expansion** | 20 - 540°C (68 - 1000°F): **15.1 x 10⁻⁶/°C** (8.4 x 10⁻⁶/°F) | 

| **Thermal Conductivity** | 12.5 W/m·K (87 Btu·in/hr·ft²·°F) at 21°C (70°F) | 

| **Specific Heat** | 460 J/kg·K (0.110 Btu/lb·°F) at 21°C (70°F) | 

| **Electrical Resistivity** | 1.02 μΩ·m at 21°C (70°F) | 

| **Modulus of Elasticity (Young's Modulus)** | 207 GPa (30.0 x 10⁶ psi) at 21°C (70°F) | 

| **Magnetic Permeability** | Essentially non-magnetic in annealed condition. | 

 --- #### **4. Mechanical Properties

 (Typical for Annealed Condition)** 

| Property | At Room Temperature | At 650°C (1200°F) | At 815°C (1500°F) | 

| :--- | :--- | :--- | :--- | 

| **Tensile Strength** | 760 MPa (110 ksi) | 380 MPa (55 ksi) | 195 MPa (28 ksi) | 

| **Yield Strength (0.2% Offset)** | 415 MPa (60 ksi) | 290 MPa (42 ksi) | 145 MPa (21 ksi) | 

| **Elongation (in 50 mm / 2 in)** | 35% | 30% | 35% | 

| **Reduction of Area** | 50% | 45% | 50% | 

| **Hardness (Rockwell B)** | 95 HRB | - | - | 

 --- #### **5. International Standards

** Multimet N155 is covered by the following international specifications: 

 *   **ASTM:**    

*   **B** (Various specifications for high-temperature alloys) 

*   **AMS:**    

*   **AMS 5760:** Bar and Forging Stock    

*   **AMS 5791:** Welding Wire 

*   **ASME:**    *   **Case** for elevated temperature service 

*   **UNS:** R30155 *   **Aerospace Standards:

**    *   Various manufacturer specifications 

 --- #### **6. Product Applications

** Multimet N155 is used in various high-temperature applications: 

 *   **Aerospace:

**    *   Gas turbine components    

*   Combustion chambers    

*   Afterburner parts 

*   **Industrial Furnaces:

**    *   Heat treatment fixtures    

*   Retorts and muffles    

*   Radiant tubes 

*   **Power Generation:

**    *   Gas turbine parts    

*   Heat exchanger components 

*   **Chemical Processing:

**    *   High-temperature reactor parts    

*   Process piping systems 

 --- #### **7. Key Characteristics & Advantages

** *   **Good high-temperature strength** up to 980°C (1800°F) 

*   **Excellent oxidation resistance

** *   **Good thermal fatigue resistance

** *   **Adequate corrosion resistance

** in various environments 

*   **Good fabricability** and weldability 

*   **Cost-effective** compared to nickel-base superalloys 

*   **Good microstructural stability

** at elevated temperatures 

 --- **Disclaimer:

** *Multimet® is a registered trademark. The values provided are typical and for informational purposes only. For critical applications, always consult the official material data sheets from the supplier and relevant design codes.*

Packing of Multimet N155,Multimet,UNS R30155

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 1673 gallon liquid totes Special package is available on request.