d Chromium is added to steel along with nickel and other metals to form stainless steel. Using your
knowledge of alloys, predict two diferences in properties between mild steel and stainless steel.
Answers
Explanation:
Metals account for about two thirds of all the elements and about 25% of the mass of the Earth. These are mainly around us in the form of metallic alloys which are used because of their various properties and characteristics, such as strength, ductility, toughness, corrosion resistance, heat resistance, thermal expansion, thermal and electrical conductivity. The strength of metals is that their atoms are held together by strong bonding forces. Such bonds are formed between metal atoms allowing their outermost electrons to be shared by all the surrounding atoms, resulting in positive ions i.e. cations being surrounded by a cloud of electrons (valence electrons). Because these valence electrons are shared by all the atoms, they are not considered to be associated with any atom in particular. This is very different from ionic or covalent bonds, where electrons are shared by one or two atoms. The metallic bond is therefore strong and uniform. Even if the added elements are non-metals, alloys still have metallic properties. Most metals are not used in their pure form bu th ave alloying elements added to modify their properties and this can be used for specific applications. The presence of a proportion of a second element associated with a metal to form an alloy, e.g. chromium with iron to form Fe-Cr alloys, can drastically alter some of its properties.