What is the definition of steel and stainless steel?

Answer 1

Any of various alloys of iron that contain chromium, nickel, and small amounts of carbon. They may also contain minor amounts of other elements, such as molybdenum. Stainless steel is resistant to rusting and corrosion.

I got this information of one of the websites in the related links.

http://www.thefreedictionary.com/stainless+steel

Answer 2

Stainless steel is the term used to describe an extremely versatile family of engineering materials, which are selected primarily for their corrosion and heat resistant properties. All stainless steels contain principally iron and a minimum of 10.5% chromium. At this level, chromium reacts with oxygen and moisture in the environment to form a protective, adherent and coherent, oxide film that envelops the entire surface of the material. This oxide film (known as the passive or boundary layer) is very thin (2-3 namometres). [1nanometre = 10-9 m]. The passive layer on stainless steels exhibits a truly remarkable property: when damaged (e.g. abraded), it self-repairs as chromium in the steel reacts rapidly with oxygen and moisture in the environment to reform the oxide layer. Increasing the chromium content beyond the minimum of 10.5% confers still greater corrosion resistance. Corrosion resistance may be further improved, and a wide range of properties provided, by the addition of 8% or more nickel. The addition of molybdenum further increases corrosion resistance (in particular, resistance to pitting corrosion), while nitrogen increases mechanical strength and enhances resistance to pitting.

Corrosion is the gradual degradation of a metal by a chemical, often electrochemical, reaction with the surrounding environment. It impacts material properties such as mechanical strength, appearance, and impermeability to liquids and gases. Although stainless steels are often chosen because of their resistance to corrosion, they are not immune to it. Whether a stainless steel is corrosion resistant in a specific environment depends on a combination of its chemical composition and the aggressiveness of the environment.

Stainless steels are often selected for their corrosion resistance, but they are often also construction materials. Mechanical properties such as strength, high-temperature strength, ductility, and toughness are therefore also important considerations.

The toughness of the different types of stainless steels shows considerable variation, ranging from excellent toughness at all temperatures for the austenitic steels to the relatively brittle behavior of the martensitic steels.

Answer 3

Stainless steel contains the metallic element- chromium- that makes it resistant to corrosion and tarnishing.