National “863” High-tech Project (863-715-21-03-01). The national “ninth Five-Year Plan” key support and promotion of high-tech new material products – self-burning ceramic composite steel pipe, is the use of high-tech production process – self-burning high temperature centrifugal synthesis method. The tube is composed of three layers of steel jade ceramic, transition layer and steel from inside to outside, and the ceramic layer is formed by dense corundum porcelain (AL2O3) at a high temperature above 2200°, and forms a firm bond with the steel pipe through the transition layer. Because the composite pipe gives full play to the high strength of the steel pipe, good toughness, impact resistance, good welding performance and corundum porcelain high hardness, high wear resistance, corrosion resistance, heat resistance, overcome the characteristics of low hardness of the steel pipe, poor wear resistance and poor toughness of the ceramic. Therefore, the composite pipe has good wear resistance, heat resistance, corrosion resistance and resistance to mechanical and thermal shock, good weldability and other comprehensive properties. It is an ideal wear-resistant and corrosion-resistant pipeline for conveying granular materials, grinding and corrosion-resistant media.
The product passed the achievement appraisal of the Ministry of Metallurgy in 1993, and passed the product appraisal meeting of “Large diameter long straight pipe SHS Ceramic composite steel pipe” co-chaired by the Ministry of Electric Power Industry and the Ministry of Metallurgical Industry (MCC Identification 2003 No. 053). Experts agree that: SHS ceramic composite steel pipe products have a leading position in China, reaching the international advanced level of similar products in the 1990s. It is a new type of composite material which is promoted by the national “ninth Five-Year Plan”.
The company cooperated with the General Institute of Iron and Steel Research of the Ministry of Metallurgy, based on the research and development of large-diameter long straight pipe composite pipe products, and researched and developed a series of special-shaped products such as corrosion-resistant, wear-resistant and heat-resistant SHS steel-porcelain composite plate and ring. Can be widely used in metallurgy, mining, electric power, coal, petrochemical and other industries, is currently the ideal patient, corrosion resistance, heat resistance composite new material.
First, sHs composite pipe mechanical properties
AL2O3 ceramic layer contains AL2O3≥90%, so the acid resistance is ≥96%, and its candle resistance is more than 10 times higher than ICr18Ni9ti stainless steel. The wear resistance is equivalent to Stellite alloy and more than 10 times higher than steel. For details, see Table 1, Table 2, Table 3, and Table 4.
Mechanical properties of sHs composite pipe Table 1
| Materials item |
Hardness HV kg/mm2 |
surface finish | Ceramic layer density g/cm2 |
Compressive shear strength MPa |
Resistance to mechanical shock(mechanicaenergy 50J point contact tube, impact times when the ceramic layer cracks | Thermal shock resistance (temperature at which the ceramic layer cracks when the water is heated three times)C | Crushing strength MPa |
Clear water resistance coefficient |
| carbon steel tubing | 149 | 411 | 0.0195 | |||||
| Ceramic composite pipe | 1100-1400 | smooth | 3.85-3.95 | 15-30 | 15 | 900 | 300-650 | 0.0193 |
SHS composite pipe wear resistance (according to stainless steel test standards) temperature 20°
| materials | 10%HCL(g/m2 .h) | 10%H2SO4(g/m2 .h) | 30%acetic acid(g/m2，h) | 30%NaOH(g/m2.h). |
| stainless steel | 0.1-1 | 3-4 | 0.1 | 0.1 |
| multiple-unit tube | 0.08-0.1 | 0.147 | 0.028 | 0 |
Acid resistance of SHS composite pipe (according to acid-proof ceramic standard ZBG94C03-86)
| materials | 10%HCL+10%H2SO4+10%HNO,heat at 90°C for 5 hours |
| acid resistant ceramics | 80% |
| SHS multiple-unit tube | 96- -98% |
Acid resistance of SHS composite pipe
| Sand blasting ratio test (sic sand) | Erosion comparison experiment of 30%SIO2 mud | ||
| materials | reduction by volume cm3 | materials | volume loss cm3 |
| 97% alumina composite pipe | 0.0025 | 45# | 25 |
| SHS multiple-unit tube | 0.0022 | SHS multiple-unit tube | 3 |
Application of shs self-burning ceramic composite pipe
Because the pipe has high wear resistance, corrosion resistance and heat resistance, it can be widely used in electric power, metallurgy, mining coal, chemical and other industries as a transport of sand, stone, pulverized coal, ash slag, liquid aluminum and other abrasive granular materials and corrosive media, is an ideal abrasion-resistant pipeline.
1.Application in metallurgy and electric power industry
Metallurgy, electric power industry transport coal powder, ash, mud, etc., need to consume a large number of metal pipes every year. The ceramic composite pipe is used to replace other pipes, which has the characteristics of high wear resistance, long life, easy installation and remarkable economic benefit. After Jinchuan Nonferrous Metals Corporation, Panzhihua Iron and Steel Company, Tanggang Mining Company, Angang Mining Company, power plants, Shandong Liaocheng Power Plant, Shanxi Yangcheng Power plant, Guizhou Anshun Power plant, Huaneng Chongqing Luohuang Power Plant, Xibaipo Power Plant and other industrial operation, its operating life of steel pipe more than ten times or even dozens of times more.
2.Application in mining and coal industry.
(1) Mine: mining carbon filling, fine ore powder and tailings transport of serious wear on the pipeline, the past use of mineral powder transport pipeline such as Panzhihua, Daye mine, etc., the service life of less than one year, use the pipe can increase the life of about 5 times.
(2) Coal: coal preparation and long-distance pipeline coal transport generally use wet transportation, requiring the transmission pipe both wear and corrosion resistance, the use of the pipe can be used as a long-life transmission pipe, considerable economic benefits.
3. Others
(1) The pipe does not pollute and does not stick to molten aluminum liquid. Aluminum melting equipment, aluminum liquid conveying pipes, and liquid riser pipes that are sensitive to iron pollution and require heavy labor to clean and maintain after use are currently ideal materials.
(2) The tube has good wear resistance and heat corrosion. It is suitable for conveying corrosive materials containing solid particles and corrosive media such as high temperature corrosive gases and sulfur-containing geothermal water.
SHS-self-burning ceramic composite pipe characteristics
1. Good wear resistance
Because the lining layer of the ceramic composite pipe is corundum ceramic (a-AL2O3), the Mohs hardness can reach 9.0, equivalent to HRC90 or more. Therefore, the grinding media transported by metallurgy, electric power, mining, coal and other industries have high wear resistance. Proven by industrial operation; Its wear life is ten times or even dozens of times that of quenched water and fire steel.
2. Low running resistance
Because the inner surface of SHS ceramic composite pipe is smooth and never corroded, it does not have a convex helix on the inner surface of seamless steel pipe. After the test of the internal surface roughness and water resistance characteristics of the relevant detection unit, the inner surface smoothness is better than any metal pipe, and the cleaning resistance coefficient is 0.0193, which is slightly lower than the seamless pipe. Therefore, the pipe has the characteristics of low running resistance, which can reduce the operating cost.
3. Corrosion resistance, anti-scaling
Because the steel ceramic layer is (a-AL2O3), it is neutral. Therefore, it has acid and alkali resistance and seawater corrosion resistance, and at the same time has anti-scale characteristics.
4. Good temperature resistance and heat shock resistance
Due to the corundum ceramic (A-al2o3), it has a single stable crystalline structure. Therefore, the composite pipe can operate normally for a long time in the temperature range of -50-700C. The linear expansion coefficient of the material is 6-8x 10-6/°C, which is about 1/2 of the steel pipe. The material has good thermal stability.
5. Low project cost
Ceramic composite pipe is light in weight and suitable in price. 50% lighter than the cast stone pipe with the same inner diameter; It is 20-30% lighter than the wear-resistant alloy tube, and has good wear resistance and corrosion resistance, because of its long service life, and the cost of supporting the hanger, handling costs, installation costs and operating costs are reduced. After the relevant design institute and construction unit project budget and project actual comparison, the pipe project cost is comparable to the cast stone, compared with the wear-resistant alloy pipe, the project cost decreased by about 20%.
6. Convenient installation and construction
Because of the light weight of the pipe, and good welding performance. Therefore, welding, flange, quick connection and other methods can be used, which is convenient for construction and installation, and can reduce installation costs.