Cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties. With modern steelmaking techniques such as powder metal forming, it is possible to make very high-carbon (and other alloy material) steels, but such are not common. Plain carbon-iron alloys with a higher than 2.1% carbon content are known as cast iron. Additional elements, most frequently considered undesirable, are also important in steel: phosphorus, sulfur, silicon, and traces of oxygen, nitrogen, and copper. Common alloying elements include: manganese, nickel, chromium, molybdenum, boron, titanium, vanadium, tungsten, cobalt, and niobium. Alloy steel is steel to which other alloying elements have been intentionally added to modify the characteristics of steel. Carbon contents higher than those of steel make a brittle alloy commonly called pig iron. Too little carbon content leaves (pure) iron quite soft, ductile, and weak. The carbon content of steel is between 0.002% and 2.14% by weight for plain carbon steel ( iron- carbon alloys). The noun steel originates from the Proto-Germanic adjective stahliją or stakhlijan 'made of steel', which is related to stahlaz or stahliją 'standing firm'. Incandescent steel workpiece in this depiction of the blacksmith's art However, steel is also very reusable: it is one of the world's most-recycled materials, with a recycling rate of over 60% globally. The modern steel industry is one of the largest manufacturing industries in the world, but is one of the most energy and greenhouse gas emission intense industries, contributing 8% of global emissions. Modern steel is generally identified by various grades defined by assorted standards organisations. Today, steel is one of the most commonly manufactured materials in the world, with more than 1.6 billion tons produced annually. įurther refinements in the process, such as basic oxygen steelmaking (BOS), largely replaced earlier methods by further lowering the cost of production and increasing the quality of the final product. The German states saw major steel prowess over Europe in the 19th century. With the invention of the Bessemer process, a new era of mass-produced steel began.

This was followed by the open-hearth furnace and then the Bessemer process in England in the mid-19th century. Steel was produced in bloomery furnaces for thousands of years, but its large-scale, industrial use began only after more efficient production methods were devised in the 17th century, with the introduction of the blast furnace and production of crucible steel. The increase in steel's strength compared to pure iron is possible only by reducing iron's ductility. These qualities include the hardness, quenching behaviour, need for annealing, tempering behaviour, yield strength, and tensile strength of the resulting steel. Varying the amount of carbon and many other alloying elements, as well as controlling their chemical and physical makeup in the final steel (either as solute elements, or as precipitated phases), impedes the movement of the dislocations that make pure iron ductile, and thus controls and enhances its qualities. The carbon in typical steel alloys may contribute up to 2.14% of its weight. In steel, small amounts of carbon, other elements, and inclusions within the iron act as hardening agents that prevent the movement of dislocations. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets.

Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Many other elements may be present or added.

Steel is an alloy made up of iron with typically a few tenths of a percent of carbon to improve its strength and fracture resistance compared to other forms of iron. The steel cable of a colliery winding tower Steels

All clad stainless steel