Ceramic steel pipes are fundamentally different from traditional steel pipes, wear-resistant alloy cast steel pipes, cast stone pipes, steel plastic and steel rubber pipes. The outer layer of the ceramic steel pipe is steel pipe and the inner layer is corundum. The Vickers hardness of the corundum layer is as high as 100-1500 (Rockwell hardness is 90-98), which is equivalent to tungsten-cobalt hard gold. The wear resistance is more than 20 times higher than that of carbon steel pipe, and it is much better than the corundum grinding wheel usually bonded. Now the corundum grinding wheel is still the main grinding wheel for various grinding machines to cut hardened steel. The corundum layer in the ceramic steel pipe can wear off the corundum grinding wheel. The wear resistance of ceramic steel pipes mainly depends on the inner layer of corundum layer with a thickness of several millimeters. Its Mohs hardness is 9, second only to diamond and silicon carbide. Among all oxides, its hardness is the highest.
The lined ceramic wear-resistant steel pipe is manufactured by self-propagating high temperature synthesis-centrifugation method. The melting point of corundum in the ceramic steel pipe is 2045 ° C. The corundum layer and the steel layer have special structures and special stress fields due to technological reasons. At room temperature, the ceramic layer is subjected to compressive stress, and the steel layer is subjected to tensile stress. Only when the temperature rises above 400°C, because the thermal expansion coefficients of the two are different, the new stress field generated by thermal expansion and the original stress field in the ceramic steel pipe cancel each other out, so that the ceramic layer and the steel layer are in a free balance state. When the temperature rises to 900 ℃, put the ceramic-lined wear-resistant steel pipe into the cold water, and soak it for many times, the composite layer will not crack or crack, showing the unparalleled thermal shock resistance of ordinary ceramics. This performance is very useful in engineering construction. Because the outer layer is steel, and the inner layer does not crack when heated up, during construction, flanges, purge ports, explosion-proof doors, etc. can be welded, and direct welding methods can also be used. It is better than wear-resistant cast stone pipe, wear-resistant cast steel pipe, rare earth wear-resistant steel pipe, bimetal composite pipe, steel plastic pipe and steel rubber pipe which are not easy to weld or cannot be welded during construction. The anti-mechanical impact performance of the lined ceramic wear-resistant steel pipe is also good, and the composite layer will not crack and fall off during transportation, installation and beating, and when the two brackets are bent and deformed by their own weight.
At present, dozens of thermal power plants have shown that the wear-resistant steel pipes lined with ceramics have high wear resistance and strong resistance to fluid erosion. In the primary air duct, the elbow wears the fastest, and the wear resistance of the ceramic-lined wear-resistant steel pipe elbow is more than 5 times higher than that of the thick-walled wear-resistant cast steel elbow.
In practice, the lined ceramic wear-resistant steel pipe was opened for observation and measurement after 1-2 years of use, and the composite layer had no obvious wear or fall off. In terms of pipes of the same specification and unit length, the weight of the lined ceramic wear-resistant steel pipe was only resistant to About 1/2 of the cast steel pipe or bimetallic composite pipe, the project cost per meter is reduced by 30-40%, only about 2/5 of the weight of cast stone pipe and rare earth wear-resistant steel pipe, and the project cost per meter is reduced by more than 20% . The price of ceramic-lined wear-resistant steel pipes used in corrosive or high-temperature places is only a fraction of the price of stainless steel pipes and nickel-titanium pipes.
Fluid pipeline transportation is not only used in the power industry, but also in metallurgy, coal, petroleum, chemical, building materials, machinery and other industries. When the materials with high abrasiveness (such as ash, coal powder, mineral concentrate, tailings cement, etc.) are transported in the pipeline, there is a problem that the pipeline wears quickly, especially the elbow wears quickly; When there is a strong corrosive gas, liquid or solid, there is a problem that the pipeline is corroded and quickly destroyed; when the material with high temperature is transported in the pipeline, there is a problem that the use of heat-resistant steel pipe is very expensive. With the launch of ceramic-lined wear-resistant steel pipes, these problems are easily solved
