Stainless steel contains a minimum of 10.5% chromium, which forms a thin, invisible, and highly adherent oxide layer on the surface of the steel called the “passive layer.” This passive layer is what makes stainless steel highly resistant to rust and corrosion.
When the steel is exposed to oxygen and moisture, the chromium in the steel reacts with the oxygen in the air to form a thin layer of chromium oxide on the surface of the steel. This chromium oxide layer is highly protective, as it is very stable and does not break down easily. As a result, it effectively prevents the steel beneath it from coming into contact with air and moisture, which are necessary for the rusting process to occur.
The passive layer is critical to the corrosion resistance of stainless steel, and the amount of chromium in the steel determines its ability to resist rust and corrosion. Higher chromium content results in a more protective passive layer and better corrosion resistance. Additionally, other elements like nickel, molybdenum, and nitrogen can also be added to the steel to improve its corrosion resistance.
Post time: Feb-15-2023