What are the phases present in iron carbon phase diagram?
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.
What does the iron-carbon diagram indicate?
The iron-carbon diagram shows the sections in which the metal only has a certain condition. These are melt, Ferrite or Austenite. Other areas are characterised by combinations of properties. These are, for example, melt and Austenite, Austenite and Ferrite, Ferrite and Perlite.
What is A3 line in iron carbon phase diagram?
The Fe- C phase diagram is shown in Fig 2. In pure iron, austenite transforms to ferrite on cooling to 912 deg C. This transition temperature is traditionally called the A3 temperature, and the diagram shows that adding C to Fe lowers the A3 temperature.
What is the carbon equilibrium diagram?
The Iron carbon equilibrium diagram (also called the iron carbon phase diagram) is a graphic representation of the respective microstructure states of the alloy iron – carbon (Fe-C) depending on temperature and carbon content.
What is microstructure of steel?
The microstructure is predominantly martensite but also has allotriomorphic ferrite, Widmanstätten ferrite, bainite and pearlite. Notice that the spherical shape of a pearlite colony is obvious in this sample because of the lack of impingment.
What is iron carbon phase diagram?
The Fe – C diagram (also called the iron – carbon phase or equilibrium diagram) is a graphic representation of the respective microstructure states of the alloy iron – carbon (Fe-C) depending on temperature and carbon content. To explain this diagram, an introduction about metal structures and pure iron must be done.
What is upper and lower critical temperature?
The upper critical temperature is the point below which cementite or ferrite begin to form. This occurs when steel is cooling from the normalizing temperature. Depending on carbon content, this point rests between 1333–1670°F. Lower critical temperature is the point of austenite-to-pearlite transformation.
What is an iron-carbon phase diagram?
The service life also improves as phase diagrams show us how to solve problems such as intergranular corrosion, hot corrosion, and hydrogen damage. The iron-carbon phase diagram is widely used to understand the different phases of steel and cast iron. Both steel and cast iron are a mix of iron and carbon.
How to determine the microstructure and phase fractions of a steel?
For steels, the microstructure and phase fractions in the iron-carbon diagram can be determined using the lever rule. For many applications it is important to know exactly what microstructure or phase fractions a steel is composed of at a certain carbon content.
What is the best way to study the microstructure of steels?
A study of the microstructure of all steels usually starts with the metastable iron-carbon (Fe-C) binary phase diagram (Figure 1). It provides an invaluable foundation on which to build knowledge of both carbon steels and alloy steels, as well as a number of various heat treatments they are usually subjected to (hardening, annealing, etc).
What is the microstructure of metastable cast iron?
In the corresponding article on cast iron, the microstructure formation of such materials is described in more detail. In principle, however, the iron-carbon phase diagram of the metastable system ends at a carbon content of 6.67 %, since the microstructure consists of 100 % cementite.