Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Because of its high tensile strength and low cost, steel is one of the most commonly manufactured materials in the world. Steel is used in buildings, as concrete reinforcing rods, in bridges, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons.
The steel cable of a colliery winding tower
An incandescent steel workpiece in a blacksmith's art
Iron ore pellets used in the production of steel
A Bessemer converter in Sheffield, England
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity, and luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength.
From left to right: three alloys (beryllium copper, Inconel, steel) and three pure metals (titanium, aluminum, magnesium)
Liquid bronze, being poured into molds during casting
A brass lamp
A gate valve, made from Inconel