Sales and production of Chaoyang large-diameter rectangular tube
According to the report of the Square Pipe Association, in the process of consumption and transportation, the square pipe surface will inevitably be oiled, affecting the quality of rust removal and phosphating, and reducing the adhesion between the coating and the substrate. So, how to remove oil from the square pipe? We briefly introduced the "stainless steel square and rectangular tube deoiling methods and influencing factors", and today we will introduce four commonly used deoiling methods. 1. Organic solvent cleaning: saponified oil and unsaponified oil are mainly dissolved in organic solvent to remove oil stains. Common organic solvents include ethanol, clean gasoline, toluene, carbon tetrachloride, C2HCl3, etc. The effective solvents are carbon tetrachloride and C2HCl3, which are not extinguished and can deoil at a higher temperature. Note that when the organic solvent is removed from the oil, additional degreasing is required. As the solvent evaporates on the surface of the rectangular tube, it usually leaves a film. In the subsequent process, the film can be removed after alkaline cleaning and electrochemical deoiling. 2. Electrochemical cleaning: It is usually used to remove oil from the cathode or through alternate anode and cathode. The hydrogen separated from the cathode or the oxygen separated from the anode after the electrochemical reaction is used to mechanically stir the solution on the surface of the rectangular tube to promote the oil on the metal surface. At the same time, the solution exchanges from time to time, which is conducive to the saponification reaction and emulsification of oil stains. Under the influence of bubbles separating from time to time, the remaining oil spots are separated from the metal surface. However, in the process of removing oil from the cathode, hydrogen often penetrates into the metal, causing hydrogen embrittlement. In order to avoid hydrogen embrittlement, the negative electrode and the negative electrode are usually used alternately to remove oil. 3. Alkali cleaning: According to the report of the Square Tube Association, a cleaning method based on alkali chemistry is widely used because of its simple use, low price and easy access to raw materials. As the alkali washing process depends on functions such as saponification and emulsification, it is impossible to use a single alkali to achieve the above performance. Many ingredients are usually used, and sometimes additives such as surfactant are added. The saponification level is determined by the alkalinity. High alkalinity can reduce the external tension between oil and solution, making oil easy to emulsify. In addition, after alkali cleaning, the residual cleaning agent on the surface of square and rectangular tubes can be removed. 4. Surfactant cleaning: Surfactant has the advantages of low surface tension, good wettability, good emulsification, etc. It is a widely used deoiling method. Through the emulsification of surfactant on the surface, an interface film with corresponding strength is formed on the oil-water interface, and the interface state is changed to make the oil particles disperse in the aqueous solution to form an emulsion. Or through the dissolution of surfactant on the surface, the insoluble oil scale can be dissolved in the surfactant micelles in the square tube, so as to transfer the oil scale to the aqueous solution.
Sales and production of Chaoyang large-diameter rectangular tube
According to the welding deformation theory, the main factors affecting the welding deformation are: the larger the weld size, the more deposited metal, and the larger the deformation; When the weld size is equal, the greater the heat input of the weld, the greater the deformation formed; When welding large and long welds, the deformation of section welding is smaller than that of straight welding; The welds are arranged asymmetrically or symmetrically but asymmetrically. The more serious the deviation of the welds, the greater the deformation; The smaller the rigidity of the component, the greater the deformation. Welding standard After process experiment and process analysis, it is confirmed that the square tube butt weld adopts double-layer CO2 gas maintenance welding. H08Mn2SiA, 1.2mm welding wire is used for welding data; The maintenance gas is pure CO2. The welding current of the first layer of weld is 200~250A, and that of the second layer is 240~320A; The arc voltage is 24~26V. The process requirements are: one layer of weld must be fully welded to ensure the reverse side is well formed; Welding current, arc voltage, wire feeding speed and welding speed can be adjusted according to the equipment model
Sales and production of Chaoyang large-diameter rectangular tube
① The rectangular straight pipe must be manufactured on the special import assembly line to ensure the manufacturing accuracy and airtightness of the air duct. ② The blanking of rectangular air duct fittings shall be completed automatically by using computer software on the imported special machine, and the automatic plasma cutting process shall be completed on the imported special plasma cutting machine for sheet metal. ③ The seam connection of rectangular air duct shall adopt the imported automatic occluder to stop the occluding process. ④ The connection between the rectangular air duct body and the plug-in flange shall adopt the rivetless connection process, and the imported equipment shall be used to stop the rivetless connection process. ⑤ The connecting flange of rectangular air duct shall adopt the connecting process of connecting plate flange and plug-in flange. When the length of the large side of the air duct is less than or equal to 2000mm, the connecting method of common plate flange shall be adopted. When the length of the large side of the air duct is more than 2000mm and less than or equal to 2500mm, the connecting method of plug-in flange shall be adopted. The rectangular air duct shall be mechanically pressed with reinforcing bars, and the spacing between reinforcing bars shall be about 300mm.
Sales and production of Chaoyang large-diameter rectangular tube
A large number of pipes are used to escort fluids, such as oil, natural gas, water, gas, steam, etc. In addition, when the bending and torsional strength are the same, the weight is light, so they are also commonly used to manufacture mechanical parts and engineering structures. It is also used for consumption of various conventional weapons. Square tubes are commonly used in various building structures and engineering structures, such as building steel for building beams, bridges, transmission towers, lifting and transportation machinery, ships, industrial furnaces, reaction towers, container racks, warehouse shelves, etc. Square tubes play a very important role in the construction industry.
Sales and production of Chaoyang large-diameter rectangular tube
Square alloy tube with ferrite structure in service. Chromium content is 11%~30%, with body centered cubic crystal structure. This kind of steel generally does not contain nickel, and sometimes contains a small amount of elements such as Mo, Ti, Nb, etc. This kind of steel has the characteristics of high thermal conductivity, small shrinkage coefficient, good oxidation resistance, stress corrosion resistance, etc. It is mostly used to manufacture parts and components resistant to atmospheric, steam, water and oxidizing acid corrosion. The application of this kind of alloy square tube is limited because of its poor plasticity, significantly reduced plasticity and corrosion resistance after welding. The application of secondary refining technology (AOD or VOD) can greatly reduce the interstitial elements such as carbon and nitrogen, thus making this kind of steel widely used.
