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Carbon Steel
Material Type
Metal
Process Compatibility
Metal Stamping, CNC Machining
Physical Properties
Parameter |
Test Standard |
Typical Range |
Remarks |
|---|---|---|---|
| Density | GB/T 223 | 7.85±0.02 g/cm³ | <0.5% variation with carbon content |
| Specific Heat | ASTM E1269 | 486 J/(kg·K) | Measured at 20℃ |
| Thermal Conductivity | ASTM E1461 | 45-54 W/(m·K) | Decreases 3% per 0.1% C increase |
| Resistivity | IEC 60468 | 0.13-0.20 μΩ·m | Measured at 20℃ |
| Permeability | ASTM A342 | Max 2000 | Fully annealed state |
Material Classification & Chemical Composition
Category |
Carbon Content |
Typical Grades (GB/ASTM) |
Primary Alloying Elements (excl. Fe) |
|---|---|---|---|
| Ultra-Low Carbon | ≤0.08% | Q195/1008 | Mn≤0.50% |
| Low Carbon | 0.08-0.25% | Q235/1020 | Mn≤1.65% |
| Medium Carbon | 0.25-0.60% | 45#/1045 | Si 0.15-0.35% |
| High Carbon | 0.60-1.00% | T8/1080 | Mn 0.30-0.90% |
| Ultra-High Carbon | 1.00-2.10% | T12/1095 | P/S≤0.040% |
Mechanical Properties
Grade |
Yield Strength (MPa) |
Tensile Strength (MPa) |
Elongation (%) |
Reduction of Area (%) |
Impact Energy (J) |
|---|---|---|---|---|---|
| Low Carbon | 185-295 | 315-460 | ≥28 | ≥55 | ≥34 |
| Medium Carbon | 345-450 | 550-700 | 18-22 | 40-50 | 25-30 |
| High Carbon | 550-850 | 850-1200 | 8-12 | 25-35 | 10-15 |
Heat Treatment Specifications
Process |
Temp. Range |
Cooling Method |
Hardness Change (HRC) |
Microstructure |
|---|---|---|---|---|
| Full Annealing | Ac3+30-50℃ | Furnace Cool | 10-15 | Ferrite+Pearlite |
| Normalizing | Ac3+50-70℃ | Air Cool | 15-25 | Fine Pearlite |
| Quenching | Ac3+30-50℃ | Water/Oil Quench | 45-65 | Martensite |
| Tempering | 150-650℃ | Air Cool | Adjust 20-50 | Tempered Martensite |
Machinability Characteristics
Machinability Index (Free-cutting steel 1215=100)
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Low Carbon: 65-75
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Medium Carbon: 55-65
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High Carbon: 40-50
Welding Parameters Recommendation
Grade |
Preheat Temp. |
Interpass Temp. |
Post-Weld Heat Treat. |
|---|---|---|---|
| Low Carbon | Optional | ≤150℃ | Generally not required |
| Medium Carbon | 150-200℃ | ≤250℃ | 600℃ Stress Relief |
| High Carbon | 250-300℃ | ≤300℃ | Mandatory Tempering |
Material Selection Decision Matrix
Consideration |
Low Carbon |
Medium Carbon |
High Carbon |
|---|---|---|---|
| Cost Effectiveness | ★★★★★ | ★★★★☆ | ★★☆☆☆ |
| Machinability | ★★★★★ | ★★★★☆ | ★★☆☆☆ |
| Heat Treatment Potential | ★★☆☆☆ | ★★★★☆ | ★★★★★ |
| Wear Resistance | ★★☆☆☆ | ★★★☆☆ | ★★★★★ |
| Weldability | ★★★★★ | ★★★☆☆ | ★☆☆☆☆ |
Other Metal Material Selection
Stainless Steel
Copper Materials
Aluminum Materials
Special Alloy
FAQ Of Carbon Steel
Visit our FAQ center for more questions.
How does Carbon content affect Carbon Steel properties?
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Low-carbon (C≤0.25%): Good plasticity, weldable, ideal for cold forming
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Medium-carbon (0.25-0.6%): Balanced strength/toughness, heat-treatable
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High-carbon (C≥0.6%): High hardness but brittle, suitable for cutting tools
Why does Carbon Steel require surface treatment?
The main weakness is corrosion susceptibility:
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Galvanizing (Zn≥80μm) prevents rust for 5-10 years
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Black oxide forms protective Fe₃O₄ layer
-
Painting is cheapest but least durable
How to select Carbon Steel for molds?
Selection criteria:
- Wear resistance: High-carbon (e.g. T8) + quenching (60HRC)
- Cost priority: 45# steel with quenching-tempering (30HRC)
- Welding needs: Low-carbon Q235 + local carburizing