1. The surface of stainless steel is prone to dust or other metal particles. If the surrounding environment is relatively humid, it will react and destroy the protective film.
2. The surface of the stainless steel is covered by some noodle soup or other sundries, so that it constitutes an organic acid. The organic acid will have a certain destructive effect on the metal for a long time.
3. There are sundries on the surface, in polluted air, or in special circumstances: nitric acid, condensed water, etc., will cause the stainless steel surface protection to fail.
