Stainless steel’s unique chemistry creates a protective layer that prevents rust, unlike regular iron or steel, which readily oxidizes when exposed to air and water. The secret lies in stainless steel’s composition: it contains at least 10.5% chromium, which reacts with oxygen to form a thin, invisible layer of chromium oxide on the surface. This “passive layer” prevents oxygen from reaching the iron, thereby stopping rust formation.
Regular steel, made of about 99% iron and up to 1% carbon, easily rusts as iron reacts with oxygen to form iron oxide. In contrast, stainless steel typically contains 62-75% iron, up to 1% carbon, and more than 10.5% chromium, along with other elements like nickel, which enhances toughness and workability. The chromium oxide layer on stainless steel can also self-heal if damaged, making it ideal for food production, surgery, and other applications due to its inert and non-leaching properties.
Stainless steel was accidentally developed in 1912 by English metallurgist Harry Brearley, who discovered its rust resistance while studying alloys to prevent corrosion in gun barrels. Although more expensive to produce than regular steel, stainless steel’s durability, resistance to corrosion, and hygienic properties make it a preferred choice in various industries today, from food safety to construction.
