Cobalt Alloy 6b,,UNS R30016,E FORU

### **Cobalt Alloy 6B / UNS R30016

** **Wear-Resistant Cobalt-Chromium-Tungsten Alloy for Severe Service Applications

** --- #### **1. Overview** **Cobalt Alloy 6B** is a wear-resistant cobalt-chromium-tungsten alloy specifically designed for applications requiring exceptional resistance to abrasion, galling, and erosion. This alloy belongs to the "Stellite" family of cobalt-based alloys and maintains its hardness and mechanical properties at elevated temperatures up to 500°C (930°F). Alloy 6B is particularly valued for its excellent metal-to-metal wear resistance, good corrosion resistance, and ability to withstand impact in demanding industrial environments. 

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

** The typical chemical composition of Cobalt Alloy 6B is outlined below. The balance is Cobalt (Co). 

| Element | Content (%) | Key Function | 

| :--- | :--- | :--- | 

| **Cobalt (Co)** | Balance | Provides the matrix with excellent wear resistance and maintains properties at elevated temperatures. | 

| **Chromium (Cr)** | 28.0 - 32.0 | Provides solid-solution strengthening and excellent corrosion/oxidation resistance. | 

| **Tungsten (W)** | 3.5 - 5.5 | Enhances hardness, strength, and wear resistance through solid-solution hardening. | 

| **Carbon (C)** | 1.0 - 1.7 | Forms hard carbides (Cr7C3, Cr23C6) that provide exceptional wear resistance. | 

| **Silicon (Si)** | 1.0 - 2.2 | Improves castability and enhances oxidation resistance. | 

| **Nickel (Ni)** | 3.0 max | May be added to improve toughness in specific formulations. | 

| **Iron (Fe)** | 3.0 max | Controlled impurity. | 

| **Manganese (Mn)** | 1.0 max | Aids in deoxidation during manufacturing. | 

| **Molybdenum (Mo)** | 1.5 max | May be added to enhance strength in specific grades. | 

 --- #### **3. Physical Properties** 

| Property | Value / Condition | 

| :--- | :--- | 

| **Density** | 8.61 g/cm³ (0.311 lb/in³) | 

| **Melting Range** | ~ 1285 - 1395 °C (2345 - 2545 °F) | 

| **Mean Coefficient of Thermal Expansion** | 20 - 540°C (68 - 1000°F): **14.2 x 10⁻⁶/°C** (7.9 x 10⁻⁶/°F) | 

| **Thermal Conductivity** | 14.9 W/m·K (103 Btu·in/hr·ft²·°F) at 21°C (70°F) | 

| **Specific Heat** | 420 J/kg·K (0.100 Btu/lb·°F) at 21°C (70°F) | 

| **Electrical Resistivity** | 0.82 μΩ·m at 21°C (70°F) | 

| **Modulus of Elasticity (Young's Modulus)** | 237 GPa (34.4 x 10⁶ psi) at 21°C (70°F) | 

| **Magnetic Permeability** | Slightly magnetic due to carbide structure. | 

 --- #### **4. Mechanical Properties

 (Typical for Cast Condition)** 

| Property | At Room Temperature | At 425°C (800°F) | At 650°C (1200°F) | 

| :--- | :--- | :--- | :--- | 

| **Hardness (Rockwell C)** | 38 - 45 HRC | 35 - 42 HRC | 30 - 37 HRC | 

| **Compressive Strength** | 1750 MPa (254 ksi) | 1450 MPa (210 ksi) | 1100 MPa (160 ksi) | 

| **Transverse Rupture Strength** | 1400 MPa (203 ksi) | 1150 MPa (167 ksi) | 850 MPa (123 ksi) |

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

 Cobalt Alloy 6B is covered by the following international specifications: 

 *   **ASTM:**    

*   **A567:** Standard Specification for Stellite Alloy Castings    

*   **B826:** Standard Specification for Cobalt-Chromium-Tungsten Alloys 

*   **AMS:**    

*   **AMS 5385:** Castings, Cobalt Alloy

*   **UNS:** R30016 

*   **ISO:**    

*   **ISO 5832-4:** Implants for surgery - Metallic materials 

*   **AWS:**    

*   **AWS A5.13:** Filler Metals for Surfacing 

 --- #### **6. Product Applications

** Cobalt Alloy 6B is widely used in severe service applications across multiple industries: 

 *   **Valve Components:

**    *   Valve seats and trim    

*   Control valve components    

*  Check valve parts 

*   **Pump and Fluid Handling:

**    *   Pump sleeves and bushings    

*   Seal rings    

*   Impeller wear rings 

*   **Mining and Mineral Processing:

**    *   Drill bits and tooling    

*   Wear plates and liners    

*   Crusher components 

*   **Aerospace:

**    *   Bearing surfaces    

*   Wear pads    

*   High-temperature wearing components 

*   **Food Processing:

**    *   Wear components in food processing equipment    

*   Cutting and slicing blades 

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

** *   **Exceptional Wear Resistance:

** Outstanding resistance to abrasion, erosion, and galling 

*   **Good Corrosion Resistance:

** Excellent performance in various corrosive environments 

*   **High Temperature Capability:

** Maintains hardness and strength up to 500°C (930°F) 

*   **Excellent Impact Resistance:** Good toughness for a hard-facing alloy 

*   **Metal-to-Metal Wear Resistance:** Superior performance in sliding contact applications 

*   **Good Machinability:** Can be machined with carbide tools in annealed condition 

*   **Versatile Application Methods:** Available as castings, wrought forms, and welding products 

 --- **Disclaimer:

** *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. Cobalt Alloy 6B is often applied as a hard-facing material or used in cast form for wear-resistant components.*

Packing of Cobalt Alloy 6b,,UNS R30016

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 1677 gallon liquid totes Special package is available on request.