What gives stainless steel its properties?

Answer 1

alloy with around 10% chromium

Answer 2

The chromium content in stainless steel alloys is what generally prevents corrosion. Pure iron, the primary element of stainless steel, is extracted from its natural state as iron ore, it is unstable by itself, and naturally wants to corrode (rust). The chromium helps to procrastinate nature's attempts to combine the pure iron with oxygen and water to form rust.

The chromium works by reacting with oxygen to form a tough, adherent, invisible, passive layer of chromium oxide film on the steel surface. If damaged mechanically or chemically, this film is self healing as long as it has enough oxygen.

Because oxygen is necessary for the reaction, liquids and other foodstuffs stored for a prolonged time in stainless can prevent oxygen contact and thus promote corrosion, as can prolonged contact with household cleaners such as bleach.

Generally, an increase of chromium content improves the corrosion resistance of stainless steels. The addition of nickel is used to raise the general corrosion resistance required in more aggressive usage or conditions. The presence of molybdenum (Mo) improves the localized corrosion resistance, such as against pitting (scarring).

Other alloying metals are also used to improve the structure and properties of stainless steels, such as Titanium, Vanadium and Copper. Non metal additions typically include natural elements such as Carbon & Nitrogen, as well as Silicon.

High-carbon stainless steel contains a minimum of 0.3% carbon. The higher the carbon content, the less formable and the tougher the steel becomes. Its hardness makes it suitable for things such as cutting edges, and other high-wear applications like plow blades. Carbon thus helps makes the edge easier to sharpen, and helps retain a sharp edge longer.

Answer 3

Stainless steel has Nickel and chrome added which gives it's rust and corrosion resistance.

Answer 4

a mixture between steel and chromium.