Different types of steel are produced for particular applications and are manufactured within precise composition limits and processing conditions in order to provide the required microstructure, properties and functionality.
Steels are alloys of iron (Fe) and carbon (C) but the mechanical properties (and the electrical or magnetic properties) are also influenced by the addition of various other elements. Carbon together with these other elements modify the allotropic (crystal structure) changes that iron displays during heating and cooling. These structural changes occur during processing or manufacture of the steel and cause the microstructure of the steel to change which in turn changes the properties of a given steel.
It is interesting to reflect that the chemical composition of steels is a consequence of some 200 years of empirical development and only since the 1960s has a more science based approach to designing steels been possible.
In the section you will be given an appreciation of the role played by chemical composition in determining the mechanical properties of steels but first please identify the typical yield strength levels required for different market applications.
Authors/Contributors:
- Robert Cochrane, Consultant