Contrary to the belief that stainless steel does not rust, I firmly claim that it is very easy to rust.
The corrosion process is omnipresent and continuous. We can quickly recognize this phenomenon in common steels due to the oxide that forms a reddish-yellow to dark brown color called rust. Such metals are called active because without any interference in them is corroded in the natural environment.
Stainless steels are passive because they also have other elements in the composition. By iron alloying with elements such as chromium and / or nickel, both 300 (304,316) and 400 (430,444) steels contain a chromium content of between 12 and 30%.
Oxygen in the atmosphere combines with stainless steel chrome (percentage of chromium in alloy between 12-30%) to form this passive oxide of chromium oxide, which further protects against corrosion. Any contamination of the surface with dirt or other materials prevents this passivation process and fixes corrosive agents that act over time, gradually reducing the corrosion protection of steel.
Conclusion: Stainless steels should be cleaned both for aesthetic reasons and to maintain corrosion resistance.
Thus, a form of routine cleaning is required to preserve the appearance and integrity of the surface.
Stainless steels are easy to clean by several different methods. It is wrong to think that the frequency of cleaning the stainless steel surfaces, unlike some other materials, would damage these surfaces, it is practically impossible to "wear out" the stainless steel surfaces by excessive cleaning. Stainless steel retains its properties best when it is clean - cleaning is essential for maximum corrosion resistance.