because the surface is oxidized.

       After the 420 stainless steel is electropolished, a passivation protective film that is not easily damaged will form on the surface, which can protect the workpiece, but the 420 material itself is a relatively easy to rust material, and it is still It can improve the rust prevention slightly, but for those with stricter requirements, such as used in special environments, such as medical equipment, etc., Hongchang recommends passivation treatment, which can improve its rust prevention effect, and can also To achieve a higher salt spray test time, the passivation treatment process for 420 stainless steel is as follows:

       Step yi: degreasing and degreasing. If the surface of the workpiece is free of oil stains, rust, impurities, or after surface polishing, no cleaning treatment is required. The surface of the workpiece cleaned with the cleaning agent needs to be cleaned and rinsed with the cleaning solution before the next process.

       Step 2: Passivation. The time is 30 minutes, and the passivation solution needs to be heated to 75-80 degrees. After the passivation treatment time is up, it is still necessary to rinse the passivation liquid on the surface of the workpiece with clean water.

       The third step: coordination. (Also called stainless steel sealing treatment) The time is 15 minutes, and the complexing agent (stainless steel sealing agent) needs to be heated to 60 degrees before operation. When the time is up, the removal of the workpiece still needs to be rinsed with clean water.

       Step 4: Pass pure water. Immerse the workpiece in barreled pure water or water filtered by a filter for 3 minutes. After the time is up, take out the workpiece for drying and packaging.