In extreme industrial environments—characterized by high temperatures, corrosive media, and molten metal erosion—reliable equipment protection is critical to maintaining production efficiency and product quality. Nitride bonded silicon carbide (NBSiC) protection tubes, a high-performance composite material composed of 70-80% silicon carbide (SiC) and 20-30% silicon nitride (Si₃N₄), stand out with exceptional properties: high-temperature resistance up to 1450℃ (1650-1750℃ in specific atmospheres), superior corrosion/abrasion resistance, excellent thermal shock stability, and high thermal conductivity. Below are their core applications, highlighting how they solve key pain points for global manufacturers.
1. Thermocouple Protection: Precise Temperature Monitoring in Harsh Conditions
Temperature control is fundamental to industrial quality and safety, and thermocouples are the primary tools for temperature measurement. However, in high-temperature furnaces, non-ferrous metal smelters, and heat treatment equipment, unprotected thermocouples are easily damaged by oxidation, corrosion, or molten metal erosion—leading to inaccurate readings, unplanned downtime, and high maintenance costs. NBSiC protection tubes are engineered to shield thermocouples, making them the top choice for extreme temperature monitoring scenarios.
Their low thermal expansion coefficient (4.4×10⁻⁶/℃) and low porosity (<1%) ensure dimensional stability and prevent corrosion from acidic/alkaline gases and molten metals. With Mohs hardness ~9, they resist wear from particulate matter. Key applications include steelmaking furnaces, aluminum melting furnaces, and ceramic kilns, where NBSiC tubes extend thermocouple lifespan by 3x or more compared to traditional alternatives.
2. Non-Ferrous Metal Smelting & Casting: Critical Process Protection
The aluminum, copper, and zinc smelting/casting industries face major challenges: molten metal erosion and contamination risks. NBSiC protection tubes serve two core roles here, delivering tailored solutions.
a. Sealed-End Tubes for Heating Element Protection
In aluminum melting furnaces, silicon carbide heating elements are essential but vulnerable to molten aluminum erosion. Sealed-end NBSiC tubes act as a barrier, isolating heating elements from molten metal to extend their lifespan and avoid contamination. Their high thermal conductivity ensures efficient heat transfer, reducing energy consumption. Customizable in diameter (up to 600mm) and length (up to 3000mm), they adapt to different furnace designs.
b. Risers for Aluminum Wheel Casting
Open-end NBSiC risers (lifting tubes) facilitate molten aluminum flow from furnaces to casting molds in aluminum wheel manufacturing. With cold modulus of rupture >150MPa and excellent thermal shock resistance (withstanding 100 cycles of 1000℃-room temperature), they ensure stable, continuous flow—reducing casting defects (porosity, inclusions) and improving yield. Unlike cast iron tubes, NBSiC does not contaminate molten aluminum, preserving product purity.
3. Chemical & Kiln Applications: Corrosion Resistance in Aggressive Environments
Chemical processing plants (petroleum cracking, acid/alkali production) and ceramic/glass kilns operate with aggressive gases and high temperatures. NBSiC tubes safeguard sensors and heating elements here, thanks to universal corrosion resistance. In petroleum cracking reactors, they resist H₂S and CO₂ corrosion at high temperatures; in ceramic/glass kilns, they protect thermocouples from oxidative atmospheres and wear, ensuring precise temperature control for quality products.
NBSiC protection tubes combine cost-effectiveness with uncompromising performance, offering longer service life, critical equipment protection, and customization. Whether in metallurgy, heat treatment, chemicals, or new energy, they deliver the reliability needed to stay competitive. Contact us today to explore customized solutions for your high-temperature and corrosion challenges.
Post time: Dec-24-2025
