Is stainless steel 100% stainless steel

Stainless steel is not a 100% rust-free material. Although its name contains "stainless", this actually refers to its extremely high resistance to corrosion

But it's not completely immune to rust. The corrosion resistance of stainless steel mainly comes from the chromium component in its alloy. Chromium can react with oxygen to form a thin and strong chromium oxide film. This passive film covers the metal surface and helps prevent further oxidation, that is, rust. process. However, in some cases, this passive membrane can be damaged, such as:

Chemical damage: A strong acid or alkali environment may corrode this protective film, exposing the metal matrix and starting to rust.
Physical damage: such as scratches or abrasions may also damage the protective film and cause localized rust.
Effect of chloride: Chloride in the ocean or salty environment is particularly easy to damage the chromium oxide layer of stainless steel, causing rust.
Overall, although stainless steel has a high level of corrosion resistance, it can still rust under extreme or inappropriate conditions. Proper stainless steel selection and regular maintenance can minimize this risk.