Silicon Carbide Protection Tube
We supply high-performance Silicon Carbide (SiC) Protection Tubes engineered to perform reliably in extreme industrial environments, including ultra-high temperatures, severe chemical corrosion, mechanical wear and frequent thermal shocks. Widely used in metallurgy, heat treatment, ceramic sintering, chemical engineering and high-temperature furnace industries, our SiC tubes act as heavy-duty protective sleeves for thermocouples, burner nozzles, heat transfer components and furnace linings, effectively extending equipment service life and reducing routine maintenance costs.
We offer three mainstream premium grades to match diverse application needs: Reaction-Bonded SiC (RBSiC), Recrystallized SiC (RSiC) and Silicon Nitride-Bonded SiC (NBSiC). Each grade features unique performance advantages, and we provide full custom manufacturing services to meet your specific size, structure and working condition requirements.
1. Custom Manufacturing Service | OEM & ODM Available
We fully understand that industrial customers have unique demands for size, structure, installation and performance. We provide complete custom solutions for SiC protection tubes, covering product design, prototype development, mass production and strict quality inspection. Our technical team will recommend the most suitable SiC grade based on your working temperature, medium type, pressure and installation space to ensure optimal performance and cost efficiency for your project.
2. Customization Range
(1) Dimension Customization: Outer diameter ranging from Φ12mm to Φ300mm, single length up to 3000mm, wall thickness customizable from 3mm to 30mm, with strict dimensional tolerances (±0.5mm to ±1.0mm) based on product specifications and process requirements to ensure perfect fit with customer equipment.
(2) Structure & End Customization: Support closed end, open end, flanged end (standard and non-standard flanges), internal and external threaded connections, sealing ring grooves, positioning holes, and other structural designs. We also provide custom special-shaped products, including 45°/90° bent tubes, reducing tubes, tees, and finned structures for specific installation and application needs.
(3) Performance Customization: Adjust material porosity, thermal conductivity, compressive strength, and corrosion resistance parameters according to special working conditions, optimize material formulation to match unique harsh environments, and improve targeted service life and performance stability.
(4) Process Customization: Flexible switching between RBSiC, RSiC, and NBSiC processes based on customer application scenarios; for complex structural parts, we prioritize near-net-shape reaction sintering process to reduce processing costs and ensure structural integrity.
Silicon Nitride-Bonded SiC (NBSiC) Protection Tubes
NBSiC tubes are made from high-purity SiC and silicon powder, formed by extrusion or grouting, then nitrided at 1350-1500°C in nitrogen atmosphere. Acicular silicon nitride crystals bond SiC particles tightly, creating a rugged composite with exceptional molten metal corrosion resistance and non-stick performance, perfect for non-ferrous metal smelting scenarios.
1. Key Performance & Features
(1) Maximum operating temperature up to 1500°C, with stable performance in molten metal and high-temperature corrosive environments
(2) Excellent resistance to molten aluminum, zinc, copper, and other non-ferrous metal corrosion, with no adhesion to molten metals and no metal liquid pollution
(3) High thermal conductivity, enabling fast temperature sensing and efficient heat transfer for precise temperature monitoring
(4) Good mechanical strength and thermal shock resistance, suitable for long-term service in metallurgical smelting and casting scenarios
(5) Low porosity and dense structure, effectively isolating molten metal, slag, and corrosive gases to protect internal components
2. Recommended Applications
NBSiC protection tubes are specially designed for metallurgical foundry industries, mainly used for molten metal temperature measurement tubes, lift tubes, aluminum/copper/zinc smelting furnace thermocouple protection sleeves, molten pool protection components, and continuous casting equipment. They are the premium solution for molten metal corrosion resistance and non-stick performance requirements.
Reaction-Bonded SiC (RBSiC) Protection Tubes
RBSiC tubes are made via advanced infiltration and reaction sintering technology, using high-purity SiC powder and carbon raw materials. Molten silicon infiltrates the green body and reacts in-situ to form a dense bonded structure, with 8-15% free silicon content. This process enables near-net shape forming with less than 1% dimensional shrinkage, delivering high cost efficiency and ideal for mass industrial production.
1. Key Performance & Features
(1) Maximum operating temperature up to 1400°C, with stable long-term service performance at continuous high temperatures
(2) High density, excellent mechanical strength, and good resistance to mechanical impact and mild abrasive wear
(3) Outstanding cost-effectiveness compared to other SiC formulations, suitable for large-scale industrial applications
(4) Superior formability, enabling the production of complex-shaped components without extensive secondary processing
(5) Good resistance to common chemical corrosion, including acidic and alkaline industrial atmospheres
2. Recommended Applications
RBSiC protection tubes are widely used for metallurgical furnace radiation tubes, standard thermocouple protection sleeves, desulfurization nozzles, heat exchangers, and general high-temperature furnace components. They are the optimal choice for applications requiring balanced performance and cost control, with no demand for ultra-high temperature resistance above 1400°C.
Recrystallized SiC (RSiC) Protection Tubes
RSiC tubes are sintered at ultra-high temperature (2100-2450°C) without any secondary binding phase, formed by direct evaporation and condensation of high-purity α-SiC particles. This pure crystalline structure ensures zero impurity contamination, making it the top choice for ultra-high temperature and high-purity working environments.
1. Key Performance & Features
(1) Ultra-high temperature resistance, with a maximum continuous operating temperature of up to 1800°C, suitable for extreme high-temperature working conditions
(2) 100% pure SiC crystalline phase, no impurity pollution, ideal for high-purity heat treatment and atmosphere-controlled furnaces
(3) Exceptional thermal shock resistance, capable of withstanding rapid temperature changes without cracking or damage
(4) High thermal conductivity and excellent high-temperature stability, maintaining structural integrity under long-term ultra-high temperature exposure
(5) Strong resistance to gas erosion and abrasive wear, suitable for harsh furnace environments with high flow rates and particle impact
2. Recommended Applications
RSiC protection tubes are mainly applied in high-temperature kilns, atmosphere furnaces, industrial heat treatment furnaces, high-temperature burner nozzles, high-purity ceramic firing equipment, and special high-temperature reaction components. They are irreplaceable for scenarios requiring ultra-high temperature resistance, high purity, and extreme thermal stability.
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Characteristic
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Si₃N₄-SiC
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R-SiC
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RB-SiC
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Long-term Operating Temperature
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1350℃
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1600℃
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1200℃
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Thermal Shock Resistance
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Optimal
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Good
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Medium
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Antioxidant Properties
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Good
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Optimal
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Medium
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Corrosion Resistance
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Strong (resistant to acids and alkalis /molten metal)
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Strong (resistant to oxidation and corrosion)
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Medium (Avoid strong alkalis/molten aluminum)
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Porosity
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3%–5%
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5%–8%
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＜1%
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Impact Resistance
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Powerful
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Weak
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Medium
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NSiC Protection Tube
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Index
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Data
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Bulk Density(g/cm3)
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2.75-2.82
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Porosity(%)
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10-12
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Compression Strength(MPa)
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600-700
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Bending Strength(MPa)
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160-180
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Young’s Modulus(GPa)
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220-260
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Thermal Conductivity(W/MK)
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15(1200℃)
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Thermal Expansion(20-1000℃) 10-6k-1
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5.0
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Max. Working Temperature(℃)
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1500
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Si3N4(%)
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20-40
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A-SIC(%)
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60-80
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Frequently Asked Questions
Need help? Be sure to visit our support forums for answers to your questions!
We are a real manufacturer, our factory is specialized in producing refractory materials for more than 30 years. We promise to provide the best price, the best pre-sale and after-sale service.
For each production process, RBT has a complete QC system for chemical composition and physical properties. And we will test the goods, and the quality certificate will be shipped with the goods. If you have special requirements, we will try our best to accommodate them.
Depending on the quantity, our delivery time is different. But we promise to ship as soon as possible with guaranteed quality.
Of course, we provide free samples.
Yes, of course, you are welcome to visit RBT company and our products.
There is no limit, we can provide the best suggestion and solution according to your situation.
We have been making refractory materials for more than 30 years, we have strong technical support and rich experience, we can help customers design different kilns and provide one-stop service.
