Ceramic-lined composite steel pipe, also known as corundum-lined wear-resistant composite pipe and ceramic composite steel pipe or ceramic wear-resistant pipe, is manufactured using a self-propagating high-temperature centrifugal synthesis process. It consists of an inner layer of corundum ceramic (α-Al₂O₃), a transition layer, and an outer steel pipe. This product is primarily used in bulk material conveying systems in the power, metallurgy, mining, and coal industries, transporting highly abrasive materials such as sand, coal powder, and ash, as well as corrosive media.

The inner ceramic layer has a Mohs hardness of 9.0 and boasts wear resistance over 20 times that of carbon steel pipe. It is resistant to acid and alkali corrosion and scale formation, and can operate stably in temperatures ranging from -50°C to 700°C. The pipe's smooth inner wall and low thermal expansion coefficient reduce fluid resistance and offer superior thermal shock resistance to ordinary ceramics. The outer steel pipe is formed using a special stress structure, either through thermite-centrifugal calcination or monolithic calcination, ensuring a secure bond between the ceramic and metal and providing strong resistance to mechanical shock. This pipe supports various connection methods, including welding and flanges, and has a lower overall cost than traditional wear-resistant materials. It is widely used in applications such as long-distance coal transportation and mine backfilling.

Application Areas

Due to its wear, corrosion, and heat resistance, this pipe is widely used in the power, metallurgy, mining, coal, and chemical industries to transport abrasive granular materials and corrosive media, such as sand, stone, pulverized coal, ash, and molten aluminum. It is an ideal wear-resistant pipe.

1. Applications in the Metallurgy and Power Industry
The metallurgy and power industry consumes a large amount of metal pipes annually to transport pulverized coal, ash, slurry, limestone gypsum slurry, and other liquids. Using ceramic composite pipes instead of other pipes offers high wear resistance, long life, easy installation, and significant economic benefits. After industrial operation in Liaocheng Changrun Thermal Power Plant, Liaocheng Zhonghua Power Plant, Beijing Beixin Building Materials Group, Henan Hebi Power Plant, Gansu Pingliang Power Plant, Taiyuan Coal Preparation Plant, Hunan Shimen Power Plant, Hebei Jinniu Energy Co., Ltd. Gequan Coal Preparation Plant, Xingtai Coal Preparation Plant, etc., its service life is more than ten times or even dozens of times that of steel pipes.

2. Application in mining and coal industry

(1) Mining: Mine filling, concentrate powder and tailings transportation cause serious wear and tear on pipelines. The service life of the ore powder transportation pipelines used in the past, such as Panzhihua and Daye mines, is less than one year. Replacing with this pipe can increase the service life by about 5 times.

(2) Coal: Coal preparation and long-distance pipeline coal transportation generally adopt wet transportation, which requires the transportation pipe to be both wear-resistant and corrosion-resistant. The use of this pipe can be used as a long-life transportation pipe with considerable economic benefits.

3. Others

(1) This pipe does not pollute or stick to molten aluminum liquid. It is an ideal material for manufacturing aluminum melting equipment, aluminum liquid conveying pipes, and liquid riser pipes that are sensitive to iron pollution and require heavy labor to organize and repair after use. (2) The pipe has good wear resistance and heat corrosion resistance. It is suitable for conveying corrosive materials containing solid particles, high-temperature corrosive gases, sulfur-containing geothermal water and other corrosive media. Process characteristics Patch wear-resistant ceramic pipe: The aluminothermic-centrifugal method is used to organically combine ceramics and metals. The aluminothermic-centrifugal method is used to prepare ceramic-lined steel pipes. The high temperature generated by the reaction itself causes the reaction products to melt and separate under the action of centrifugal force to form a steel pipe lined with alumina ceramic. Self-propagating composite pipe: Ceramic powder + iron oxide powder + magnesium oxide powder are mixed in proportion (the main component is iron oxide, black), the two ends of the pipe are sealed, the powder is added, the pipe is rotated, electronic ignition is carried out, and the powder is sintered on the inner wall of the pipe by centrifugal method. Integrally calcined ceramic pipe: According to the mold, the ceramic powder is sintered into a ceramic pipe, and then combined with the steel pipe. The ceramic tube's outer wall and steel tube's inner wall are assembled by pouring a special filler (cement or epoxy resin) into the steel tube, then isostatically pressing.

Performance and Characteristics

1. Excellent Wear Resistance

The ceramic composite tube's inner lining is made of corundum ceramic (a-Al₂O₃), achieving a Mohs hardness of 9.0, equivalent to over HRC90. This makes it highly resistant to abrasive media used in industries such as metallurgy, power generation, mining, and coal mining. Industrial operation has ten proven its wear life to be or even dozens of times longer than that of hardened steel.

2. Corrosion and Scaling Resistance

Because the steel-ceramic layer is (a-Al₂O₃), it possesses neutral properties. It is resistant to acid, alkali, and seawater corrosion, and also exhibits anti-scaling properties.

3. Low Operating Resistance

SHS ceramic composite Tubes have a smooth, rust-resistant inner surface and lack the convex spiral lines found on seamless steel pipes. Testing of the inner surface roughness and clear water resistance properties by relevant testing units revealed that the pipe's inner surface smoothness surpasses that of any other metal pipe. Its clear water resistance coefficient is 0.0193, slightly lower than that of seamless pipe. This pipe therefore offers low operating resistance, reducing operating costs.

4. Excellent Temperature Resistance and Heat-Shock Resistance

Because the corundum ceramic (a-Al₂O₃) has a single, stable crystalline structure, the composite pipe can operate normally over a temperature range of -50°C to 700°C for extended periods. The material's linear expansion coefficient is 6-8×10⁻⁶/°C, approximately half that of steel pipe. The material exhibits excellent thermal stability.

5. Low Project Cost

Ceramic composite pipes are lightweight and affordable. They are 50% lighter than cast stone pipes of the same inner diameter and 20-30% lighter than wear-resistant alloy pipes. They also offer excellent wear and corrosion resistance, and their long service life reduces support, handling, installation, and operating costs. A comparison of project budgets and actual construction results by relevant design institutes and construction companies revealed that the construction cost of this pipe is comparable to that of cast stone pipe and approximately 20% lower than that of wear-resistant alloy pipe.

6. Easy Installation and Construction

Due to the pipe's light weight and excellent weldability, it can be installed using welding, flanges, and quick-connect methods, making it easy to install and reducing installation costs.

Principle and Function

Ceramic steel pipes are fundamentally different from traditional steel pipes, wear-resistant alloy cast steel pipes, cast stone pipes, and steel-plastic and steel-rubber pipes. Ceramic steel pipes have a steel outer layer and a corundum inner layer. The corundum layer has a Vickers hardness of 100-1500 (Rockwell hardness of 90-98), equivalent to tungsten-cobalt hard gold. Its wear resistance is over 20 times greater than that of carbon steel pipes, making it far superior to conventional bonded corundum grinding wheels. Corundum grinding wheels are still the primary grinding wheels used in various grinding machines for hardened steel. The corundum layer in ceramic steel pipes can wear away the corundum grinding wheels. The wear resistance of ceramic steel pipes relies primarily on a several-millimeters-thick inner layer of corundum, which has a Mohs hardness of 9, second only to diamond and silicon carbide and the highest hardness of all oxides.

Ceramic-lined wear-resistant steel pipes are manufactured using a self-propagating high-temperature synthesis (SHS) centrifugal process. The melting point of the corundum in ceramic steel pipes is 2045°C. Due to the unique structure and stress field of the corundum and steel layers, the process is unique. At room temperature, the ceramic layer is subject to compressive stress, while the steel layer is subject to tensile stress. expansion, leaving the ceramic and steel layers in a state of free equilibrium. When the temperature rises to 900°C and the ceramic-lined wear-resistant steel pipe is repeatedly immersed in cold water, the composite layer remains intact and does not crack or break, demonstrating unparalleled thermal shock resistance compared to ordinary ceramics. This property is highly beneficial in construction. Because its outer layer is steel, and the inner layer remains resistant to cracking even at elevated temperatures, flanges, purge ports, explosion-proof doors, and other components can be welded or directly connected during construction. This significantly Outperforms wear-resistant cast stone pipe, wear-resistant cast steel pipe, rare earth wear-resistant steel pipe, bimetallic composite pipe, steel-plastic pipe, and steel-rubber pipe, which are difficult or impossible to weld during construction. Ceramic-lined wear-resistant steel pipe also offers excellent resistance to mechanical impact. The composite layer remains resistant to cracking and shedding during transportation, installation, and bending deformation caused by its own weight between two supports.

Dozens of thermal power plants have demonstrated that ceramic-lined wear-resistant steel pipe exhibits high wear resistance and strong resistance to fluid erosion. Bends in primary air ducts are the most susceptible to wear, and ceramic-lined bends offer over five times the wear resistance of thick-walled wear-resistant cast steel bends.

In practice, ceramic-lined wear-resistant steel pipes, when opened and inspected after one to two years of use, show no noticeable wear or shedding of the composite layer. For pipes of the same specifications and unit length, ceramic-lined wear-resistant steel pipes weigh only about half as much as wear-resistant cast steel pipes or bimetallic composite pipes, reducing the per-meter construction cost by 30-40%. They weigh only about two-fifths as much as cast stone pipes and rare earth wear-resistant steel pipes, reducing the per-meter construction cost by over 20%. pipes.

Fluid pipeline transportation is used not only in the power industry but also in a wide range of industries, including metallurgy, coal, petroleum, chemicals, building materials, and machinery. When conveying highly abrasive materials (such as ash, coal dust, mineral concentrate, and tailings cement), pipelines can quickly wear out, especially elbows. When conveying highly corrosive gases, liquids, or solids, pipelines can be corroded and quickly damaged. high-temperature materials, heat-resistant steel pipes are prohibitively expensive. The advent of ceramic-lined wear-resistant steel pipes has addressed these issues.

Notes:
1. The steel pipe specifications in this table refer to GB8163-87 and are made of 20# steel.
2. Lengths are manufactured to customer specifications. Lengths longer than 3 meters are welded (flange or quick-connect).
3. The ceramic layer thickness is typically 3-6mm.
4. D (the outer diameter of our steel pipe) and theoretical weight in the table are for reference only.
5. Other specifications can be manufactured according to customer specifications.