ABSTRACT
The subject of microstructures is very important because it serves as a means to analyze and compare the mechanical properties of all materials. The intent is to try to relate to the viewer the significant features of the microstructure such as size of the grains, relative amounts of each microconstituent, and the identity of each. The inverse lever rule is applied to the microconstituent diagram to determine the amount and composition of the microconstituents in the same manner that it is applied to a phase diagram to determine the amount and composition of the phases. A phase diagram contains no information regarding the mechanical properties of the alloys formed from its components. Since the steels are the most widely used material for structural components, the iron-carbon microconstituent diagram is discussed, and some examples are given to demonstrate the common microstructures that are associated with it.
