Definition & Purpose
A recarburizer (or carbon additive) is a carbon-rich material added to molten iron/steel to:
Adjust carbon content (compensate for carbon loss during smelting)
Improve mechanical properties (hardness, strength, wear resistance)
Enhance casting quality (reduce porosity, improve fluidity)
Common Types of Recarburizers
|
Type |
Carbon Content |
Key Features |
Applications |
|
Calcined Petroleum Coke (CPC) |
98–99.5% C |
Low sulfur (<0.5%), high purity |
Steelmaking, ductile iron |
|
Graphitized Petroleum Coke (GPC) |
98–99.9% C |
Superior conductivity, low nitrogen |
High-grade steel, EAF/LF refining |
|
Coal-based Carburizer |
90–95% C |
Cost-effective, higher ash/sulfur |
Foundry (gray iron) |
|
Charcoal-based |
85–93% C |
Renewable, low sulfur but high volatile |
Small foundries, eco-friendly |
Key Quality Indicators
Fixed Carbon: ≥95% preferred (minimizes impurities)
Sulfur Content: ≤0.5% (critical for high-grade steel)
Ash Content: ≤1% (reduces slag formation)
Particle Size: 1–10mm (optimizes dissolution rate)
Nitrogen Content: ≤300ppm (avoids steel embrittlement)
How to Select a Recarburizer?
|
Factor |
Optimal Choice |
|
Steel Grade |
Ultra-low sulfur CPC for stainless steel |
|
Process Type |
GPC for EAF/LF; coal-based for cupola furnaces |
|
Cost Sensitivity |
Coal-based for budget-sensitive applications |
|
Environmental Needs |
Charcoal-based for green foundries |