Self-propagating high temperature synthesis technology of corundum ceramic composite steel pipe is that is, “SHS” technology composite, is a national High-tech “863” project, is the original national metallurgical Industry Department, the Ministry of Electricity Project focused on the promotion of new products, the tube from within to outside by ceramic (corundum) layer, transition layer and steel layer composed of three parts.
The ceramic lined pipe transport has been widely used in the industries of electric power, metallurgy, coal, petroleum, chemical engineering, building materials, mechanism and so on.
- Good abrasion resistance
Ceramic composite pipe due to the inner lining of corundum ceramic (A-al2o3), the Mo hardness of up to 9.0 of the equivalent HRC90. Therefore, the metallurgical, electric power, mining, coal and other industries to transport the grinding medium has high wear resistance. The industrial operation confirms that its wear-resisting life is 10 times times or even dozens of times times that of quenched steel.
- Small Operation resistance
SHS Ceramic Composite pipe Because of the smooth inner surface, and never rust, nor like the seamless steel tube inside the surface has convex spiral. After testing the internal surface roughness and water resistance characteristics of the testing units, the smoothness of the inner surface is superior to any metal pipe, the resistance coefficient is 0.0193, slightly lower than the seamless pipe. Therefore, the tube has the characteristics of small operating resistance and can reduce the operating cost.
3, corrosion resistance, anti-scaling
Because the steel ceramic layer is (A-al2o3), it is a neutral trait. Therefore, with acid and alkali resistance and seawater corrosion, and at the same time with anti-scaling and other characteristics.
- High temperature resistance and heat-resisting performance
The corundum ceramic (A-al2o3) is a single stable crystalline structure. Therefore, the composite pipe can operate in the -50–700℃ temperature range for a long time. The material linear expansion coefficient is 6-8×10-6/0c, about 1/2 of the steel pipe. The material has good thermal stability.
- Low construction cost
The ceramic composite pipe is light in weight and suitable for price. than the same inner diameter cast stone pipe weight 50% lighter than the wear-resistant alloy tube weight light 20–30%, and wear-resistant, corrosion-resistant, because of long service life, thereby supporting the hanger costs, removal costs, installation costs and operating costs reduced. Compared with the engineering budget and engineering practice of the Design Institute and Construction Unit, the cost of the pipe project is equal to that of cast stone, and the project cost is about 20% lower than that of wear-resisting alloy pipe.
- Convenient installation and construction
Because of the light weight of the tube, and good welding performance. Therefore, welding, flange, rapid connection, such as the installation of convenient construction, and can reduce installation costs.
Iv. Other Knowledge
Ceramic steel pipe and traditional steel pipe, wear-resistant alloy cast steel pipe, cast stone pipe, as well as steel plastic, steel rubber pipe, etc. have essential differences. The outer layer of ceramic steel pipe is steel, and the inner is corundum. The Vickers hardness of 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 times higher than carbon steel pipe, it is superior to the corundum grinding wheel which is usually bonded. Now the corundum grinding wheel is still the main grinding wheel of the grinding mill. The corundum layer in the ceramic steel tube can wear away the corundum grinding wheel. The abrasion resistance of ceramic steel tube is mainly by the inner layer of several millimeters thick corundum layer, its Morse hardness is 9, second only to diamond and SIC, in all oxides, its hardness is the highest.
The inner liner ceramic wear-resisting steel pipe is made by SHS high temperature synthesis-centrifugal method, the melting point of corundum in ceramic steel pipe is 2045 ℃, the corundum layer and steel layer have special structure and stress field because of the process reason. Under normal temperature, the compressive stress of the ceramic layer, the tensile stress of the steel layer, the two opposites, into a balanced whole. Only when the temperature rises to more than 400 ℃, because the thermal expansion coefficient is different, the new stress field produced by the thermal expansion and the original stress field in the ceramic steel pipe cancel each other, so that both the ceramic layer and the steel layer are in a free equilibrium state. When the temperature rises to 900 ℃ the inner liner ceramic wear-resistant steel pipe into the water, repeatedly soaked repeatedly, the composite layer does not crack or cracking, showing the incomparable thermal shock resistance of ordinary ceramics. This performance is of great use in construction, because the outer layer is steel, in addition to heating the inner layer does not crack, in the construction, the flange, blowing, explosion-proof doors can be welded, but also can be directly welded to connect, which is more than wear-resistant cast stone pipe, wear-resistant cast steel pipe, Rare-earth wear-resistant steel pipe, bimetal composite pipe, steel pipe, Steel rubber pipe In the construction is not easy to weld or welding more than a chip. Internal liner ceramic Wear-resistant steel pipe resistance to mechanical impact is good, in transport, installation beat and the two support between the weight bending deformation, the composite layer does not break off.
At present, the practice of dozens of thermal power plants shows that the wear resistance of the inner-lined ceramic steel tube is high, and the resistance to fluid scouring is strong. In the first air duct, the bending pipe wear the most quickly, the wear resistance of the inner liner ceramic wear-resisting steel pipe is more than 5 times times higher than that of the thick wall wear-resisting cast steel elbow.
In practice, the inner liner ceramic wear-resistant steel pipe after 1-2 years to open observation and measurement, the composite layer has no obvious wear or fall off, in the same size and unit length of the pipeline, the internal liner ceramic wear-resistant steel tube weight only wear-resistant cast steel pipe or bimetal composite pipe of about 1/2, the cost of each of the meters reduced 30–40%, Only cast stone pipe and Rare-earth wear-resistant steel pipe weight of about 2/5, per meter project cost reduction of more than 20%. In the corrosive or high-temperature place to use the liner ceramic wear-resistant steel pipe, its price is only a stainless steel tube, nickel-titanium tube of a fraction of.
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 pipe is transported with large grinding material (such as ash residue, pulverized coal, mineral fine powder, tailings cement, etc., there is a problem of fast abrasion of pipe, especially the bending pipe wear fast; when conveying a strong corrosive gas, liquid or solid in the pipeline, there is a problem that the pipeline is corroded and destroyed quickly. When conveying the material with high temperature in the pipeline, there are some problems such as the price of heat-resisting steel pipe is very expensive. The internal liner ceramic wear-resistant steel pipe market, these problems are solved.