1. The standard of corrosion resistance is determined artificially. It is necessary to recognize it, use it, and not be restricted by it. The specific standard of corrosion resistance should be determined according to the specific use requirements. At present, the corrosion resistance of stainless steel mostly adopts the 10-level standard. Which level is selected as the corrosion resistance requirement depends on the characteristics of the equipment and each part (thickness, size). Service life, product quality (such as impurities, color, purity), etc., generally speaking, for equipment, meters and components that require smooth mirrors or precise dimensions during use, you can choose 1 to 3 standards; closely cooperate with the requirements For equipment that does not leak for a long time or requires limited use, the components are selected from 2 to 5 levels. For equipment that does not require high maintenance and easy maintenance or requires a short life, the components can be selected from 4 to 7, except for special exceptions, stainless steel is in use Under the conditions, the annual corrosion rate is more than 1mm. Generally, it is not used. It should be pointed out that the level 10 standard is not applicable when local corrosion occurs.
2. The processing corrosion resistance of stainless steel parts is relative and conditional. It is often said that the stainless steel is not rusty. Corrosion resistance refers to the relative rust and non-corrosion resistance, which means under certain conditions (medium, concentration , Temperature, impurities, pressure, flow rate, etc. at a certain time). Up to now, there is no stainless steel that has rust and corrosion resistance in any corrosive environment. Therefore, the personnel of optional materials must choose according to the specific conditions of use. After the stainless steel grade is selected, the user department must also target the selected stainless steel. The characteristics of stainless steel are used correctly, that is, reasonable selection of materials and correct use can achieve the purpose of rust resistance or corrosion resistance.
3. The choice of stainless steel parts for processing stainless steel should consider both its general corrosion resistance and local corrosion resistance. In some water and chemical media, the latter needs to be paid more attention. This is because the material selection personnel generally pay more attention to it. The general corrosion resistance of stainless steel, and under the conditions of use, their sensitivity to local corrosion, such as stress corrosion pitting corrosion, etc., is less considered; the local corrosion of stainless steel is mostly in a corrosive environment with good general corrosion resistance. Occurrence, local corrosion often leads to the sudden destruction of stainless steel equipment and components, which is far more harmful than general corrosion.