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How to choose a good Fireproof board manufacturer?

How to choose a good Fireproof board manufacturer?

2023-07-31

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Research on the Development and Application of New Thermal Insulation Materials

Research on the Development and Application of New Thermal Insulation Materials

2023-07-31

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Aluminum plate type characteristics

Aluminum plate type characteristics

There are two types of aluminized steel plates: one is called Class 1, which is based on heat resistance and can withstand a high temperature of about 640 ° C. This aluminized steel plate is coated with a 20-25 μ m thick Al Si alloy (6-8.5% Si content) coating on the low-carbon steel plate. The other is called Type 2, which is based on corrosion resistance, and its coating thickness is 2-3 times that of Type 1. Regardless of the type, the coating is formed by hot dip plating. Therefore, a thin alloy layer is formed between the low-carbon steel plate substrate and the coating. Type 1 forms an Al Fe Si alloy layer and Type 2 forms an Al Fe alloy layer. Compared with category 1, category 2 has a lower melting point and a thicker coating, so its weldability is poor. characteristic Aluminum steel plate is a combination of iron and aluminum, which are widely used in our daily life. This steel plate can make full use of the characteristics of two metals to form a steel plate with special properties. Because of its unique properties such as good corrosion resistance, heat resistance and heat dissipation, this kind of steel plate is more and more popular. The aluminized steel plate is used in the environment of heat radiation, acid, condensate and atmospheric corrosion. It has good corrosion resistance. In rural areas, industrial cities and marine areas, parts made of aluminized steel plate can last longer than galvanized steel plate. Parts made of steel plates are 2 to 5 times larger and are particularly suitable for corrosion resistance to SO and HS. High temperature oxidation resistance and thermal radiation reflectivity Thermal radiation reflectivity is another characteristic of aluminized steel plate to control, block and restrain thermal radiation. In a short time, its performance is comparable to that of pure aluminum, but superior to that of galvanized steel. According to the inspection, after four years of outdoor use in the urban suburbs, the thermal radiation reflection capacity of galvanized steel plate has dropped to only 5%, similar to the black body absorbing all radiant heat, while the aluminum plated steel plate is still 55%.

2023-01-09

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The reason why aluminized plate is more resistant to high temperature

The reason why aluminized plate is more resistant to high temperature

Other precautions for aluminized pipe welding: 1) The pipe head shall be clean and free from oil, water and other impurities. 2) The welding current shall be strictly controlled to prevent overheating from damaging the aluminized layer inside the tube. 3) It is prohibited to conduct arc striking test on the pipeline, and the grounding wire shall not be connected with the pipeline to prevent the arc striking from damaging the penetration layer. Why should the tube plate end face of aluminized plate heat exchange tube bundle undergo anti-corrosion treatment after welding? To ensure the continuity of anti-corrosion performance of tube plate end face after heat exchange tube bundle welding. Can aluminized plate heat exchange tube bundle undergo strength expansion? Why? The basic requirement of strength expansion joint is that the hardness of the pipe is less than that of the tubesheet, which will cause plastic deformation of the pipe and elastic deformation of the tubesheet, so as to achieve strength connection. The situation is just the opposite after aluminizing the tube, so the strength expansion between the tube and tube sheet of the aluminized plate heat exchange tube bundle is not allowed.

2023-01-09

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Widespread application of aluminized plate process

Widespread application of aluminized plate process

Aluminizing process is one of the effective methods for steel surface corrosion prevention. The aluminized steel has stable characteristics in oxidizing and corrosive media, will not damage the mechanical properties of raw materials, can greatly improve its service life, and can replace expensive heat-resistant steel and stainless steel in various environments. Therefore, it has attracted much attention in recent years. Through constant research and development, we have made technological progress. With the continuous development of acid making technology, various new equipment, new processes and new materials are constantly put into use. In order to save costs, improve production efficiency and stability, it is particularly important to carry out anti-corrosion and anti-oxidation treatment on steel pipes for acid making equipment. The aluminizing process of steel pipes shall be strictly controlled. Put the preliminarily treated steel pipe material into the aluminum liquid at the set temperature, so that the molten iron reacts with the aluminum liquid, so that the aluminum diffuses to the steel pipe surface, forming a ferro aluminum alloy layer, thus significantly improving its oxidation resistance, corrosion resistance and other properties, and extending its service life. The aluminized layer can effectively separate the humid air from the base metal and effectively prevent the electrochemical corrosion of the base metal. Foreign testing institutions have carried out exposure tests for a long time, and found that aluminized steel samples have no oxidation or rust on the surface after 20 years of air placement test. In the chemical industry, especially in the acid making equipment, the corrosion resistance of metals is highly required. After aluminizing treatment, a stable, dense, pore free and continuous aluminum alloy layer is formed on the metal surface by using the electrochemical characteristics of aluminum, which can effectively prevent the invasion of corrosion media, so as to achieve the purpose of corrosion prevention. Aluminizing process is one of the effective methods for steel surface corrosion prevention. The steel treated by this process has stable characteristics in oxidizing and corrosive media, will not damage the mechanical properties of raw materials, can greatly improve its service life, and can replace expensive heat-resistant steel and stainless steel in various environments. The aluminized plate process can be divided into immersion type and diffusion type according to different processes. The steel pipe material is directly taken out for cooling and curing after being dipped in high temperature aluminum liquid. Due to its rough surface formation and uneven thickness of aluminum coating, it is difficult to meet the parameter requirements, and gradually replaced by diffusion aluminizing process. Diffusion aluminizing process is to add thermal diffusion link before cooling. The process flow includes oil removal rust removal pre plating hot dip aluminizing correction cleaning inspection diffusion treatment correction cleaning and inspection. The diffusion aluminizing process adds the high temperature annealing stage on the basis of the immersion process. The aluminized material after hot dip is put into a high temperature furnace, heated to above 800 ° C for several hours, and then taken out for cooling. This high temperature process is a diffusion annealing process, which can melt and diffuse the aluminized layer on the steel surface. It also eliminates the unique dentate feature of pure aluminum layer and replaces it with aluminum iron alloy layer and solid molten crystal structure, so as to obtain the material characteristics of oxidation resistance, high temperature resistance and corrosion resistance.

2023-01-09

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How to judge the quality of aluminized plate process

How to judge the quality of aluminized plate process

Aluminized plate is a kind of surface chemical heat treatment method to form aluminum iron alloy coating on steel surface in molten aluminum. The aluminized layer can be divided into immersion type and diffusion type according to its production method. After hot dip plating, the workpiece is directly taken out of the molten aluminum solution and solidified by air cooling. Its surface is not smooth, there are often aluminum adsorption and excessive aluminum solution solidification, and the thickness is uneven. The typical structure of impregnated aluminized plate can be roughly divided into two layers: the outer layer is pure aluminum, and the chemical composition is similar to the original aluminum solution. Below the pure aluminum layer is a composite layer formed by the mutual diffusion of aluminum and iron, which is distributed in the irregular tooth shaped steel matrix. The diffusion type is to put the workpieces after hot dip aluminizing into an air electric furnace, heat them to 850-920 ℃, keep them warm for 3-4 hours, and take them out for air cooling. In this diffusion annealing process, the aluminum on the surface melts and diffuses into the metal matrix, and the pure aluminum layer disappears without zigzag features, thus forming the aluminum iron compound and solid molten crystal structure on the surface, which has high temperature resistance, oxidation resistance and corrosion resistance. A large number of experiments and practices at home and abroad have proved that as long as the aluminum content on the surface of aluminized layer is not less than 7%, it can protect the metal matrix, slow down or even prevent oxidation and corrosion. The thickness and concentration of aluminized layer are two main indicators to evaluate the aluminizing quality of aluminized parts, but the more critical is the aluminum concentration on the surface of aluminized parts, not the thickness. The coating with thin aluminized layer and high aluminum concentration is more resistant to high-temperature oxidation and corrosion than the coating with thick aluminized layer and low aluminum concentration. The corrosion resistance of aluminized plate determines the aluminum content of aluminized layer. When the aluminum content in the aluminized layer reaches 8% (WT%), the corrosion resistance is significantly improved. The current standard generally requires that the aluminum content of the aluminized layer is greater than 15% (WT) and the atomic content of the aluminized layer is greater than 30%. The protective effect on metal materials is reflected in two aspects: first, a dense, strong adhesion and extremely stable Al2O3 protective film is formed on the surface of the infiltrated layer, which has strong self repair and regeneration capabilities. The results show that when the aluminizing amount is more than 8% (WT%), a continuous protective film can be formed. Second, the aluminized layer is a large anode in the liquid medium, and the aluminum in the aluminized layer is consumed for a long time to protect the base metal from corrosion. What should be paid attention to in the use of aluminized plate furnace lining? 1. Please install the furnace lining in strict accordance with the furnace lining installation manual. 3. Pay close attention to the change of furnace lining in the use process and handle it in time. 2. After the installation of furnace lining, clean up the sundries in the furnace. When opening the new furnace lining, the blanking must be careful. Do not throw large iron blocks into the furnace lining to avoid damage to the furnace lining. When the furnace opens the installed new furnace lining, the medium frequency power supply cannot be pulled too fast, which is conducive to the combination of furnace lining and fixed filler. 4. The lining wall becomes thinner after a certain number of times of use. When the wall thickness of the furnace lining is about to be less than 1 cm, the furnace lining shall be stopped and replaced with a new one.

2023-01-09

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