Steel phase diagrams are provided here to show you some illustration of the steel phase such as austenite, carbide, cementite, and ferrite. This kind of phase diagram of austenite is useful since the transformation behavior of austenite does not change dramatically unless the steel has a large concentration of solutes. Take a look at the following austenite steel phase diagram below.
Before you study each steel phase diagram, you should know that each phase within an alloy has its own distinct physical, mechanical, electrical, and electrochemical properties. For example, in carbon steel, ferrite is a relatively soft phase and cementite is a hard, brittle phase. When they are present together, the strength of the alloy is much greater than for ferrite and the ductility is much better compared to cementite. Thus, an alloy with more than one phase can be considered to be a composite material.
Each phase field within a phase diagram indicates the phase or phases present for a particular alloy composition and temperature. For the iron-carbon phase diagram, the phase fields of interest are the ferrite, cementite, austenite, ferrite + cementite, ferrite + austenite, and austenite + cementite phase fields.
The phase diagram illustrates the domains in which particular phases or combinations of phases are stable, and contains information about their equilibrium compositions. It is important to understand the phase transformations. We hope our diagrams will help you understand the phase!