Why is green silicon carbide an ideal material for producing high-temperature furnace tubes?
Green silicon carbide is produced by high-temperature smelting in an electric resistance furnace from raw materials such as quartz sand, petroleum coke, and sawdust (with salt added during production). It possesses characteristics such as high hardness, high strength, strong corrosion resistance, good chemical/high-temperature stability, good self-sharpening properties, high-temperature stability, high thermal conductivity, and low coefficient of thermal expansion.
High-temperature furnace tubes are key components in industrial high-temperature equipment, widely used in metallurgy, chemical industry, power generation, petrochemical industry, aerospace, and other fields. They can operate stably in extreme high-temperature, high-pressure, and corrosive environments.
The reason green silicon carbide is an ideal material for high-temperature furnace tubes is determined by its inherent characteristics:
1. High-temperature resistance and superior thermal shock resistance
Green silicon carbide can be used stably for extended periods above 1600℃, and some silicon nitride-bonded products can withstand temperatures up to 1750℃. It is also resistant to cracking under drastic temperature changes, exhibiting excellent thermal shock resistance.
2. High Thermal Conductivity and Significant Energy Saving
Green silicon carbide itself has a thermal conductivity of 6.28-9.63 W·m⁻¹·k⁻¹, which is 10-14 times that of ordinary clay bricks. This allows for rapid and uniform heat transfer, reducing energy consumption. It is particularly suitable for gas-fired external radiant furnaces and electric heating internal radiant tubes, achieving temperature balance and energy savings.
3. Excellent Wear and Corrosion Resistance
Green silicon carbide has a Mohs hardness of 9.4, second only to diamond. Its products have wear resistance 5-20 times that of cast iron. It also exhibits good corrosion resistance to acids, alkalis, and other chemicals, making it suitable for long-term operation in harsh environments such as metallurgy and chemical industries.
4. High Structural Strength and Adaptability to Complex Components
It can be used to manufacture furnace linings, nozzles, irregularly shaped parts, and high-temperature support structures. Its high mechanical strength allows it to withstand material erosion and high-temperature loads, ensuring equipment stability.
In summary, green silicon carbide is rightfully considered an ideal material for producing high-temperature furnace tubes.