White Cast Iron is a hard, brittle, and extremely wear-resistant form of cast iron, characterized by its white, crystalline fracture surface. This appearance results from iron carbides (Fe₃C) instead of graphite.
Its exceptional hardness and abrasion resistance make it ideal for severe wear environments, although its brittleness limits machinability and impact performance.
Chemical Composition
| Element | Typical Range (%) | Role |
|---|---|---|
| Carbon (C) | 2.0 – 3.6 | Carbide formation |
| Silicon (Si) | 0.3 – 1.0 | Suppresses graphite |
| Manganese (Mn) | 0.3 – 1.5 | Stabilizes carbides |
| Chromium (Cr) | 0 – 30 | Carbide former |
| Nickel (Ni) | 0 – 5 | Toughness (alloyed) |
| Molybdenum (Mo) | 0 – 3 | Hardenability |
| Phosphorus (P) | ≤ 0.10 | Controlled |
| Sulfur (S) | ≤ 0.05 | Controlled |
| Iron (Fe) | Balance | Matrix |
Key Mechanical Properties
| Property | Typical Range |
|---|---|
| Tensile Strength | 200 – 600 MPa |
| Compressive Strength | 1,000 – 2,000 MPa |
| Hardness | 400 – 700 HB |
| Elongation | ~0% |
| Impact Strength | Very Low |
| Wear Resistance | Excellent |
Physical Properties
| Property | Typical Value |
|---|---|
| Density | 7.2 – 7.6 g/cm³ |
| Melting Range | 1,150 – 1,250 °C |
| Thermal Conductivity | 15 – 30 W/m·K |
| Specific Heat | ~460 J/kg·K |
| Thermal Expansion | 10 – 12 µm/m·°C |
| Fracture Appearance | White, crystalline |
Key Characteristics
✔ Exceptional abrasion resistance
✔ Extremely high hardness
✔ Retains hardness at elevated temperatures
✔ Unsuitable for machining
Available Forms
Sand-cast wear parts
Centrifugally cast liners
Chill cast components
High-chromium white iron castings
Composite wear castings
Applications
Crusher liners and grinding media
Mining chutes, hoppers, and mill liners
Cement clinker crushers and fan blades
Pulverizers and ash handling equipment
Agricultural and earthmoving wear parts
Advantages
✔ Outstanding wear resistance
✔ Very high hardness
✔ Long service life in abrasive service
✔ Cost-effective vs tool steels
Limitations
❌ Extremely brittle
❌ Poor impact resistance
❌ Difficult to machine or weld
❌ Requires precise casting control
Why Choose White Cast Iron?
White cast iron is chosen when abrasive wear dominates and toughness requirements are secondary. It excels in sliding, erosive, and crushing environments with minimal impact loading.