(View exact match)

CATEGORY: geology
DEFINITION: An alloy of iron and carbon in which the carbon content amounts to about 2 percent or less. Steel appears in the archaeological record during the Iron Age and was usually produced by carburization of wrought iron. In this process, the iron is heated in a hearth with charcoal to about 800 degrees Centigrade. Carbon diffuses into the surface of the metal to make steel. As only the surface is affected, only thin strips of steel could be made by this method. Some Iron Age artifacts are made of such steel strips forged together. Further processes such as quenching and tempering were known from Roman times. Viking swords combined the strength of wrought iron with the hardness of steel, using a technique known as pattern welding.

Display More Results