Choosing the right silicon carbide grade for steelmaking depends mainly on furnace type, cost control, and performance stability.
In most practical applications, SiC 88 is widely used in large-scale steel production where cost efficiency is critical, while SiC 90 is preferred when higher purity and more stable reaction performance are required.
What Is Silicon Carbide Used for in Steelmaking
In steelmaking, silicon carbide (SiC) is mainly used as a deoxidizer and carbon additive. It helps reduce oxygen content in molten steel while improving carbon recovery efficiency.
In electric arc furnace (EAF) operations, silicon carbide is often used to accelerate temperature rise and improve slag fluidity, especially during secondary refining stages. Compared with traditional materials, SiC can provide a faster reaction and better thermal efficiency.
For a broader understanding of how silicon carbide functions across industries, you can also read:
👉 Silicon Carbide in Metallurgy: Applications, Benefits and Specifications
Key Factors When Choosing Silicon Carbide Grade
1. Furnace Type
In our experience working with steel plants, furnace type plays a key role in grade selection.
EAF (Electric Arc Furnace):
SiC 90 is often preferred due to its higher purity and more stable reaction behavior.
BOF (Basic Oxygen Furnace):
SiC 88 is more commonly used because it offers a better balance between cost and performance.
This difference becomes more obvious in large-scale operations where stability directly affects production efficiency.
2. Cost vs Performance
For steel producers focusing on cost efficiency, SiC 88 is usually sufficient for most applications.
However, some plants switch to SiC 90 when they require:
- more stable carbon recovery
- lower impurity impact
- tighter control over chemical composition
In practice, the choice is rarely about "which is better," but rather which is more suitable under specific production conditions.
3. Impurity Content and Stability
Impurities such as Fe₂O₃ and Al₂O₃ can significantly affect steel quality.
In actual production environments, higher impurity levels may lead to:
- unstable carbon recovery
- increased slag formation
- inconsistent reaction performance
This is why higher-grade silicon carbide is often selected for applications where quality consistency is critical.
For more detailed information on composition and grades, refer to:
👉 Silicon Carbide Specifications: Grades, Sizes and Chemical Composition
SiC 88 vs SiC 90 (Practical Comparison)
| Grade | SiC Content | Typical Application | Key Advantage |
|---|---|---|---|
| SiC 88 | ~88% | Bulk steelmaking | Lower cost |
| SiC 90 | ~90% | High-quality steel / casting | More stable performance |
In real production scenarios, SiC 88 is widely used in cost-sensitive operations, while SiC 90 is selected when stability and performance consistency are more important.
If you want a deeper comparison, see:
👉 SiC80 vs SiC90 Silicon Carbide in Metallurgy and Refractory Applications
Typical Usage and Dosage
In most steelmaking processes, silicon carbide is typically added at around 1–2 kg per ton of molten steel under stable conditions.
However, when higher carbon recovery is required, the dosage may increase to up to 3 kg per ton, depending on:
- furnace condition
- carbon requirements
- slag composition
In our experience, improper dosage is one of the most common reasons for unstable performance, especially when switching between different grades.
Common Problems and Practical Solutions
Problem 1: Unstable Carbon Recovery
One common issue reported by steel plants is unstable carbon recovery when using lower-grade silicon carbide.
This is often caused by:
higher impurity content
inconsistent particle size
👉 Solution:
Using higher purity grades such as SiC 90 or optimizing particle size distribution can significantly improve performance stability.
Problem 2: Slag Build-Up and Reaction Inefficiency
In some cases, excessive impurities can increase slag volume and reduce reaction efficiency.
👉 Solution:
Selecting material with controlled impurity levels and stable composition is critical.
Problem 3: Inconsistent Batch Performance
Variations between batches can lead to unpredictable results in steelmaking.
👉 Solution:
Work with reliable suppliers who can ensure consistent chemical composition and particle size control.
Practical Recommendation
Based on industry practices:
- Choose SiC 88 if your priority is cost efficiency and large-scale production
- Choose SiC 90 if you need better stability, lower impurity levels, and more consistent performance
More importantly, supplier reliability plays a key role in ensuring stable results.
If you are evaluating suppliers, you may find this guide helpful:
👉 How to Choose a Silicon Carbide 88 90 Manufacturer
Frequently Asked Questions about Silicon Carbide in Steelmaking
Q1: How do I choose between SiC 88 and SiC 90 for steelmaking?
A:The choice depends on your production priorities. SiC 88 is typically used for cost-sensitive large-scale steel production, while SiC 90 is preferred when higher purity and more stable reaction performance are required, especially in high-grade steel applications.
Q2: What is the typical dosage of silicon carbide in steelmaking?
A:Silicon carbide is usually added at around 1–2 kg per ton of molten steel under stable conditions. In cases where higher carbon recovery is needed, the dosage can increase to up to 3 kg per ton, depending on furnace conditions and slag composition.
Q3: Why does silicon carbide improve carbon recovery in steelmaking?
A:Silicon carbide acts as both a carbon source and a deoxidizer. It reacts efficiently in molten steel, helping reduce oxygen levels while improving carbon absorption, which leads to more stable and efficient steelmaking processes.
Q4: What problems can occur when using low-grade silicon carbide?
A:Low-grade silicon carbide may contain higher impurity levels, which can lead to unstable carbon recovery, increased slag formation, and inconsistent reaction performance. This is why higher purity grades are preferred in applications requiring stability.
Q5: Is supplier quality important when selecting silicon carbide?
A:Yes, supplier consistency is critical. Even with the same grade, variations in chemical composition and particle size can affect performance. Reliable suppliers ensure stable batch quality and predictable results in steelmaking operations.
Not sure whether to use SiC 88 or 90? This guide explains the real differences, typical dosage (1–3 kg/ton), and how to choose the right grade for your steelmaking process.
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