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Causes & Prevention Measures of the Corrosion of Stainless Steel Tubes
Feb 13, 2022
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1. The corrosion phenomenon of stainless steel tubes
Corrosion occurs in the whole interface of the stainless steel tube and the medium environment. It is characterized by uniform thinning along the cross section, mostly in acid and hot alkali medium environment. The overall corrosion resistance of stainless steel is often evaluated by corrosion rate (mm/a).
2. The corrosion reasons of stainless steel tubes
The passive film cannot be formed. The passive film is not stable. The passive film is damaged and can not be repaired in time. The stainless steel tubes, even in a blunt state, often dissolve at different rates (sometimes even very slowly) in practical engineering applications and in many electrolyte corrosion environments. Finally, due to the stainless steel control equipment, components and containers will be gradually reduced and in failure.
Many people think that stainless steel tubes will not rust. This is the wrong view. First of all, the rust resistance and corrosion resistance of stainless steel tubes is conditional. The chromium content of steel must be more than 12%. If the chromium content is low or not in the atmosphere and other weakly corrosive environment (including in the atmosphere and other weakly corrosive environment, but with Cl local rich collection concentration conditions), the rust will occur. The acid resistant steel pipe is corrosion resistant in acid, alkali, salt and other strong corrosive medium, but it is also corrosion resistant under certain conditions, such as medium type, temperature, concentration, impurity content, flow rate, pressure and so on. There is no stainless steel tube that is not rusty and corrosion-resistant under any conditions in the world.
Because of this, we must choose and use stainless steel tubes correctly. The correct choice is to choose the stainless steel tube according to the requirements of specific conditions of use. Reasonable use is for the rust, corrosion resistance characteristics of stainless steel tubes. The wrong choice or unreasonable use will make stainless steel tubes rust and corrosion. The quality of the problems of stainless steel tubes will also lead to rust and corrosion of stainless steel tubes. Therefore, the quality of stainless steel tubes is the premise of correct selection and reasonable use of stainless steel tubes.
The corrosion of stainless steel tubes is simply the damage and failure caused by chemical and electrochemical action between stainless steel tubes and the corrosive medium. Classified by the nature of the corrosion effect, it can be divided into chemical etching and electrochemical corrosion. (Chemical etching is produced in the electrolyte solution of corrosion, such as stainless steel tubes under high temperature oxidation. Electrochemical corrosion refers to steel and stainless steel tubes in wet air, in aqueous solution and acid, alkali salt electrolyte solution generated by the corrosion. Ion (electronic) is in the process of corrosion produced. The essence of electrochemical corrosion is the action of galvanic cells.
3. The prevention measures of corrosion of stainless steel tubes
According to the type of corrosion medium, concentration, temperature and other conditions as well as the specific requirements of the use, we select the grade of corrosion resistance. According to the requirementsof corrosion resistance grades, we choose the appropriate grade of stainless steel.
Below is the list of 10 standards of overall corrosion resistance of stainless steel tubes. We can know which level can be chose to meet the requirements of corrosion resistance of equipment and components. In addition to the length of life, the characteristics of equipment, components (thick, thin, large or small) and the quality of the products produced (impurities, purities, colors, etc.) requirements are also considered. The impurities, purity, color of the product has special requirements for the purpose, we generally choose one to three standards. The requirements are not high. The convenient maintenance or life requirements are not very long, we can choose four to six standards. However, in normal circumstances, we do not choose criteria greater than six standards.
Corrosion occurs in the whole interface of the stainless steel tube and the medium environment. It is characterized by uniform thinning along the cross section, mostly in acid and hot alkali medium environment. The overall corrosion resistance of stainless steel is often evaluated by corrosion rate (mm/a).
2. The corrosion reasons of stainless steel tubes
The passive film cannot be formed. The passive film is not stable. The passive film is damaged and can not be repaired in time. The stainless steel tubes, even in a blunt state, often dissolve at different rates (sometimes even very slowly) in practical engineering applications and in many electrolyte corrosion environments. Finally, due to the stainless steel control equipment, components and containers will be gradually reduced and in failure.
Many people think that stainless steel tubes will not rust. This is the wrong view. First of all, the rust resistance and corrosion resistance of stainless steel tubes is conditional. The chromium content of steel must be more than 12%. If the chromium content is low or not in the atmosphere and other weakly corrosive environment (including in the atmosphere and other weakly corrosive environment, but with Cl local rich collection concentration conditions), the rust will occur. The acid resistant steel pipe is corrosion resistant in acid, alkali, salt and other strong corrosive medium, but it is also corrosion resistant under certain conditions, such as medium type, temperature, concentration, impurity content, flow rate, pressure and so on. There is no stainless steel tube that is not rusty and corrosion-resistant under any conditions in the world.
Because of this, we must choose and use stainless steel tubes correctly. The correct choice is to choose the stainless steel tube according to the requirements of specific conditions of use. Reasonable use is for the rust, corrosion resistance characteristics of stainless steel tubes. The wrong choice or unreasonable use will make stainless steel tubes rust and corrosion. The quality of the problems of stainless steel tubes will also lead to rust and corrosion of stainless steel tubes. Therefore, the quality of stainless steel tubes is the premise of correct selection and reasonable use of stainless steel tubes.
The corrosion of stainless steel tubes is simply the damage and failure caused by chemical and electrochemical action between stainless steel tubes and the corrosive medium. Classified by the nature of the corrosion effect, it can be divided into chemical etching and electrochemical corrosion. (Chemical etching is produced in the electrolyte solution of corrosion, such as stainless steel tubes under high temperature oxidation. Electrochemical corrosion refers to steel and stainless steel tubes in wet air, in aqueous solution and acid, alkali salt electrolyte solution generated by the corrosion. Ion (electronic) is in the process of corrosion produced. The essence of electrochemical corrosion is the action of galvanic cells.
3. The prevention measures of corrosion of stainless steel tubes
According to the type of corrosion medium, concentration, temperature and other conditions as well as the specific requirements of the use, we select the grade of corrosion resistance. According to the requirementsof corrosion resistance grades, we choose the appropriate grade of stainless steel.
Below is the list of 10 standards of overall corrosion resistance of stainless steel tubes. We can know which level can be chose to meet the requirements of corrosion resistance of equipment and components. In addition to the length of life, the characteristics of equipment, components (thick, thin, large or small) and the quality of the products produced (impurities, purities, colors, etc.) requirements are also considered. The impurities, purity, color of the product has special requirements for the purpose, we generally choose one to three standards. The requirements are not high. The convenient maintenance or life requirements are not very long, we can choose four to six standards. However, in normal circumstances, we do not choose criteria greater than six standards.
