Steel and Process Of Making Steel

Steel is the fundamentally an alloy of iron and carbon, with the carbon content varying up to 1.5 percent. The carbon is distributed throughout the mass of the metal, not as elemental or free carbon but as a compound (chemical combination) with Iron.

If however, the carbon is increased above 1.5 percent , a stage soon arrives when no more carbon can be combined state and any excess must be present as free carbon ( graphite ). It is at this stage that the metal merges into the group termed cast iron. Therefore, for a material to be classed as steel there must be no free carbon in its composition ; Immediately free graphite that occurs passes into the category of cast Iron.

Besides carbon, there are other elements present in the steel , e. g ; Sulphur, silicon, Phosphorus , manganese, e t c ; but carbon is by for the most important modifying element . Iron forms the mass of the alloy: It is the quantity partner while on carbon falls the duty of determining the quality of the steel to meet demand which iron alone cannot satisfy. The Importance of carbon in steel lies not in its relative volume but in its remarkable influence on the internal structural changes and subsequently cooled by various methods.

STEEL MAKING PROCESS :

The commercial Process of making steel are :

(1) Bessemer Process ,

(2) L-D Process,

(3) Open - Hearth Process,

(4) Crucible Process,

(5) Electric Process,

(6) Duplex process.

The Bessemer , Open hearth and electric process can be sub - divided into

(a) Acid Process ,

(b) Basic Process ,

According to the type of lining used in the furnace. In each of these processes, the steel is produced either by adding carbon to wrought iron or by removing the proper portion of carbon from pig iron by first completely de-carburizing pig iron, and then adding the proper amount of carbon.

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Mechinopedia For Mechanical Engineers

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