In the selection of stainless iron waste bin used in corrosive environment, in addition to detailed understanding of the application conditions of stainless iron waste bin, the main factors to be considered are: corrosion resistance, strength, resistance, physical function, processing, forming function, resource, price and difficulty in obtaining of stainless iron waste bin.
①The specification of corrosion resistance is confirmed artificially. It should be recognized, applied, but you cannot be restricted by it. The detailed specification of corrosion resistance should be confirmed according to the application requirements. For the corrosion resistance of stainless iron trash cans, most people use a 10-grade standard. When it comes to which grade should be selected as the corrosion resistance requirement, the characteristics of the equipment and parts (thin or thickness, large or small size), the length of service life, product quality (such as impurities, color, purity) and other requirements should be considered.
Generally speaking, for the equipment appearance and components that require bright mirror or precise scale in the application process, specifications of level 1-3 can be selected; For the equipment that requires close cooperation, no leakage for a long time or the use of limited length, level 2-5 components can be selected; For the equipment that requires low maintenance convenience or short service life, level 4-7 components can be selected. Except for special exceptions, the stainless iron waste bin with annual corrosion rate of more than 1mm will generally be unselected under the application conditions. It should be pointed out that the specification of level 10 is not applicable when partial corrosion occurs.
②The corrosion resistance is relative, conditional and often referred to as the rust resistance of stainless iron waste bin, which means that it must be under certain conditions (media, concentration, temperature, impurities, pressure, flow rate, etc.).
Up to now, there is no stainless iron waste bin with rust resistance and corrosion resistance in any corrosive environment. Therefore, the selection personnel must make selection according to the detailed application conditions. After the trademark of stainless iron waste bin is selected, the application department should also correctly uses the characteristics of the selected stainless iron waste bin, that is to say, reasonable material selection and correct application can achieve the purpose of rust resistance or corrosion resistance.
③Not only corrosion resistance function, but also partial corrosion resistance function should be considered in the stain steel trash bins selection. In some water medium and chemical medium, the latter should be paid more attention to. This is because the selection personnel generally pay more attention to the general corrosion resistance function of stainless iron waste bin.
Under the application conditions, their sensitivity to partial corrosion, such as stress corrosion pitting, is less considered. The partial corrosion of stainless iron waste bin often occurs in the corrosion environment with good general corrosion resistance function, and the partial corrosion often leads to the sudden damage of equipment and components of stainless iron waste bin, which is far more harmful than the general corrosion.
④When using the corrosion resistance data of stainless iron waste bin in various manuals, it should be noted that many of the data are only the experimental results in some experiments, which often have a large gap with the practical medium environment. In order to obtain the corrosion resistance data closer to the practical application conditions, the corrosion experiment of practical medium or the coupon experiment under the field condition should be carried out in the laboratory, and the experiment of imitation device should be carried out when necessary.
Under some application conditions, this kind of situation will also be encountered. When the working medium or the industrial products produced contain a small amount of metal ions in a certain kind of or a stainless iron waste bin, the quality of industrial products (including luster, color, purity, etc.) in the chemical process will be affected.
It is most common in industries such as nuclear fuel pharmaceuticals and pigments. At the moment, stainless iron waste bin without certain elements or corrosion resistance level of stainless iron waste bin selected is often selected, so as to reduce metal ions to the allowable limit.
⑤If the equipment and parts of stainless iron waste bin fail due to corrosion, the causes of corrosion and damage shall be analyzed, and measures shall be taken after finding out the causes, instead of throwing them away.