The discussion centers on the preferred crystal structures of steel, specifically the Body-Centered Cubic (BCC) structure at lower temperatures (ferrite phase) and the Face-Centered Cubic (FCC) structure at higher temperatures (austenite phase). The addition of carbon to iron alters its properties and influences these phase transitions, as depicted in the iron-carbon equilibrium diagram. Understanding the metallurgy of steel and the effects of temperature on its microstructure is crucial for applications in material science.
PREREQUISITESMaterial scientists, metallurgists, and engineers interested in the properties and applications of steel, particularly those focusing on the effects of temperature and alloying elements on crystal structures.
Brian Yao said:What are the reasons behind the different microstructures of steel at different temperatures? I don't understand why steel at high temperatures (austenite phase) would favor an FCC crystal structure while steel at lower temperature (ferrite) would favor a BCC crystal structure.
Okay I understand that carbon in Fe strengthens the metal by creating distortions within the lattice but I don't understand how temperature plays a role in determining the preferred crystal structure.drvrm said:carbon in small quantities is added to iron and one can get steel.
the size of carbon atoms is less than the spacing between iron atoms so it goes in and forms a solid solution-thus deforming the structure of iron.
The iron-carbon equilibrium diagram (phase diagram) is a plot of transformation of iron with respect to carbon content and temperature.
this admixture of carbon leads to several changes in its properties -stress bearing and ductileness etc.
If one observes the metallurgy of steel in detail related to its various phases your question can be handled-
its better you see a site which handles your querry...
ref; <http://nptel.ac.in/courses/105106112/1_introduction/2_metallurgy_of_steel.pdf>