Stainless steel is a steel alloy that contains a minimum chromium content of 10.5%. The chromium reacts with the oxygen in the air and forms a protective layer that makes stainless steel highly resistant to corrosion and rust. At the moment, there are over 150 varieties of stainless steel in the market.

Because of its low maintenance nature, resistance to oxidation and staining, stainless steel is preferred in many applications, particularly those where aesthetics matter.

Even with these impressive features, stainless steel can and does rust after all, it’s 'stainless' not 'stainfree'. Some types of stainless steel are more prone to corrosion than others, depending on the chromium content. The higher the chromium content, the less likely the metal will rust.

But, over time and if not maintained correctly, rust can and will develop on stainless steel.

Factors Affecting Rust on Stainless Steel

Various factors can affect the ability of stainless steel to resist corrosion. The composition of the steel is the single biggest concern when it comes to corrosion resistance. The elements in the different grades of stainless steel can have adverse effects on corrosion resistance.

The environment where the metal is used is another factor that can amplify the chances of stainless steel rusting. Environments with chlorine like swimming pools are highly corrosive. Also, environments with salty water can accelerate corrosion on stainless steel.

Finally, maintenance will have an effect on the metals ability to resist rust. The chromium in stainless steel reacts with oxygen in the air to produce a protective chromium oxide layer across the surface. Although very thin, this layer is what protects the metal from corrosion. This layer can be destroyed by harsh environments or mechanical damage such as scratches however, if cleaned properly and in a suitable environment, the protective layer will form again restoring the protective properties.