the provision of what is needed for the well-being or protection of a person or thing: He is under the care of a doctor. With proper care, the watch will last a lifetime. temporary keeping, as for the benefit of or until claimed by the owner: He left his valuables in the care of friends.
Iron is used more than any other metal for producing metal alloys. The most important iron alloys include cast iron, pig iron, wrought iron, and steel. There are various alloys of steel, but they all contain iron as the main metal. Carbon is one of the main alloying elements mixed with iron to make steel.
However, its use only became widespread in the 14th century, when smelting furnaces (the forerunner of blast furnaces) began to replace forges. Iron ores are rocks from which metallic iron can be economically extracted. These rocks are usually found in the form of hematite (Fe2O3) or magnetite (Fe3O4). About 98% of world iron ore production is used to make iron in the form of steel.