Iron and Types of Iron...

Iron and Types of Iron Iron is a chemical element with symbol Fe (from Latin word Ferrum). Its atomic number is 26 and atomic mass is 55.85. It has a melting point of 1538 deg C and boiling point of 2862 deg C. The density of iron is 7.87 grams/cu cm. It is a metal in the first transition series. Like the elements of other group 8 elements (ruthenium and osmium), iron exists in a wide range of oxidation states, ?2 to +6, although +2 and +3 are the most common. Iron as a common metal is mostly confused with other metals such as different types of steels. Iron is by mass the most common element on the earth, forming much of earth’s outer and inner core. It is the fourth most common element and the second most common metal in the earth crust. Steels contain over 95 % Fe. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen and water. Fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals which form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, exposing fresh surfaces for corrosion. Iron objects have been found in Egypt dating from around 3500 BCE (Before Common Era). They contain around 7.5 % nickel, which indicates that they were of meteoric origin. The ancient Hittites of Asia Minor (today’s Turkey) were the first to smelt iron from its ores around 1500 BCE. The ‘Iron Age’ had begun at that time. The first person to explain the various types of iron was René Antoine Ferchault de Réaumur who wrote a book on the subject in 1722. This explained how steel, wrought iron, and cast iron, were to be distinguished by the amount of charcoal (carbon) they contained. The...