Tungsten Overlay
Tungsten carbide overlay provides the highest hardness and erosion resistance, making it ideal for extreme and localized wear.
Chromium carbide overlay offers a balanced combination of hardness, toughness, and cost, making it the most widely used wear plate technology for industrial applications.
- Description
A tungsten overlay is a wear-resistant surface created by welding or cladding tungsten carbide (WC) onto a steel substrate.
It is often compared with chromium carbide overlay (CCO), which is another widely used hardfacing system based on chromium carbides (Cr₃C₂, Cr₇C₃).
Both systems are used to protect equipment from abrasion, erosion, and impact, but they perform very differently.
Basic Material Differences
| Feature | Chromium Carbide Overlay | Tungsten Carbide Overlay |
|---|---|---|
| Main Carbide | Chromium carbides | Tungsten carbides |
| Typical Hardness | HRC 58–65 | HRC 70–75 |
| Carbide Size | Fine and uniform | Very dense and extremely hard |
| Wear Mechanism | Sliding abrasion | Extreme abrasion + erosion |
| Cost Level | Medium | Very high |
Wear Resistance Comparison
Tungsten carbide is one of the hardest industrial materials available.
It provides exceptional resistance to:
-
High-velocity particle erosion
-
Severe scratching and cutting
-
Slurry abrasion
Chromium carbide is optimized for:
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Bulk material abrasion
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Sliding wear
-
Moderate impact
In typical bulk material handling systems, chromium carbide overlays provide the best cost-to-performance ratio, while tungsten carbide is used for extreme wear points.
Impact and Crack Resistance
| Property | Chromium Carbide | Tungsten Carbide |
|---|---|---|
| Crack Resistance | Good | Lower |
| Impact Tolerance | Moderate to high | Low |
| Brittleness | Low | High |
Tungsten carbide is much harder, but also more brittle.
In applications with impact or vibration, chromium carbide performs more reliably.
Typical Applications
Tungsten Carbide Overlay
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Sandblasting nozzles
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Oil and gas drilling tools
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Pump impellers
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Slurry valves
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Precision wear parts
Chromium Carbide Overlay
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Mining liners
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Conveyor chutes
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Hoppers
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Cement plant equipment
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Coal handling systems
Service Life Strategy
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Tungsten overlay is selected when maximum hardness and erosion resistance are required.
-
Chromium carbide overlay is selected when large surface areas and cost-effective wear protection are needed.
