Carbide Plate
Different carbide overlays serve different wear conditions.
Chromium carbide is the most widely used and cost-effective.
Tungsten carbide provides ultimate hardness but higher cost.
Complex alloy overlays deliver the best balance of wear, impact, and temperature resistance.
- Description
A Carbide Plate, also known as a hardfacing plate or overlay plate, is a wear-resistant steel plate with a hard alloy layer welded onto a base metal (usually mild steel or low-alloy steel).
The hardfacing layer determines the plate’s hardness, wear resistance, and temperature performance — making it the key factor for choosing the right product.
Different carbide materials are used depending on the working environment, from standard abrasion to extreme impact or high temperature.
1. Common Types of Hardfacing Layers
| Type of Hardfacing Layer | Main Carbide | Typical Composition | Hardness (HRC) | Main Features | Common Applications |
|---|---|---|---|---|---|
| Chromium Carbide Overlay (CCO) | Cr₇C₃ / Cr₃C₂ | Fe–Cr–C | 58–65 | Excellent sliding abrasion resistance; moderate impact resistance | Cement, power, mining, steel mills |
| Tungsten Carbide Overlay (WCO) | WC | Fe–Cr–W–C or Ni–W–C | 68–75 | Extremely high hardness; superb wear life; limited impact resistance | Dredging, oil drilling, cutting tools, high wear nozzles |
| Niobium Carbide Overlay (NbC) | NbC | Fe–Cr–Nb–C | 60–68 | Improved toughness and crack resistance; handles impact better | Mining buckets, crushers, impact liners |
| Vanadium Carbide Overlay (VC) | VC | Fe–Cr–V–C | 58–64 | Very fine carbide structure; good balance of wear and toughness | Cement screws, sand transport, conveyor systems |
| Molybdenum Alloyed Overlay (MoC or Cr–Mo–C) | Mixed Cr/Mo carbides | Fe–Cr–Mo–C | 55–62 | Excellent heat resistance; stable up to 800 °C | High-temperature hoppers, furnaces |
| Complex Carbide Overlay (Multi-alloy) | Cr + Nb + V + Mo carbides | Fe–Cr–Nb–V–Mo–C | 60–68 | Superior resistance to multiple wear types (abrasion + impact + temperature) | Mining, metallurgy, cement clinker lines |
2. Chromium Carbide Overlay (CCO) – The Most Common Type
The chromium carbide layer is the most widely used overlay in wear plates.
It features:
Hardness: 58–65 HRC
Carbide phase: Cr₇C₃
Excellent wear resistance under dry sliding or fine particle abrasion
Stable performance up to 600–800 °C
This type is ideal for chutes, hoppers, fan blades, cyclones, and coal pipelines.
3. Tungsten Carbide Overlay – For Extreme Wear
Tungsten carbide hardfacing offers the highest hardness (up to 75 HRC) among all overlay types.
It provides exceptional resistance to abrasion and erosion, even in slurry or sand-laden environments.
Extremely low wear rate
Used for oil drilling tools, dredger components, and wear rings
More costly, but lasts 3–5× longer than chromium carbide under the same conditions
4. Niobium and Vanadium Carbide Overlays – Balanced Performance
To improve the brittleness of standard chromium carbide overlays, NbC and VC are added to enhance impact and crack resistance.
These “complex carbide” layers provide a balance of:
High hardness
Better impact resistance
Good metallurgical bonding
Extended wear life in dynamic conditions
Common in mining equipment, cement screws, crushers, and mixing blades.
5. Complex Alloy Carbide Overlays – Multi-Element Systems
Modern wear plates often use multi-alloy overlays combining Cr, Nb, Mo, V, and W to achieve composite wear resistance.
They can handle environments involving:
Sliding abrasion
Impact wear
High temperature (up to 850 °C)
Mild corrosion
These plates are the premium choice for severe service applications such as clinker coolers, crusher walls, and heavy-duty conveyors.
6. Base Metal Options
While the overlay layer defines wear performance, the base metal provides structural strength.
| Base Metal | Description | Suitable For |
|---|---|---|
| Mild Steel (Q235 / A36) | Low cost, good weldability | General wear applications |
| Low Alloy Steel (Q345 / A572) | Higher strength and toughness | Heavy-duty applications |
| Stainless Steel (304 / 316) | Corrosion resistance | Chemical and marine environments |
7. Summary
| Overlay Type | Main Advantage | Typical Hardness | Temperature Limit |
|---|---|---|---|
| Chromium Carbide | General wear resistance | 58–65 HRC | 600–800 °C |
| Tungsten Carbide | Extreme abrasion resistance | 68–75 HRC | 600 °C |
| Niobium Carbide | Improved impact strength | 60–68 HRC | 700 °C |
| Complex Alloy | All-round high performance | 60–68 HRC | 850 °C |
