What is C on a phase diagram?
Point C is the critical point of the substance, which is the highest temperature and pressure at which a gas and a liquid can coexist at equilibrium. The figure below shows what happens when we draw a horizontal line across a phase diagram at a pressure of exactly 1 atm.
How do you use phase diagrams?
A typical phase diagram has pressure on the y-axis and temperature on the x-axis. As we cross the lines or curves on the phase diagram, a phase change occurs. In addition, two states of the substance coexist in equilibrium on the lines or curves.
What phase is carbon steel?
Phases that occur in iron-carbon alloys are molten alloy, austenite (gamma phase), ferrite (alpha phase), cementite, and graphite. These phases are also called constituents. Not all constituents (such as pearlite or bainite) are phases—these are microstruc- tures.
What is C Fe?
Iron carbide (FeC) | CFe – PubChem.
What is austenite in Fe C diagram?
Austenite Austenite is the interstitial solid solution of carbon in gamma (γ) iron. It has FCC structure. Austenite can have maximum 2.14% carbon at 1143°C. Austenite is normally not stable at room temperature.
What are the different phases present in the Fe-C system?
The stable equilibrium phases of the Fe-C system at ambient pres- sure are (1) the gas, g; (2) the liquid, L; (3) bcc (~iFe); (4) fcc (yFe), or austenite; (5) bcc (~tFe), or ferrite; and (6) hexagonal (C), or graphite.
What is austenite in Fe-C diagram?
How many phases are in the Fe-C phase diagram?
Four solid phases
1. Solid phases in the Fe-Fe3C phase diagram: Four solid phases, namely α-Ferrite, Austenite, Cementite (Fe3C), and δ-Ferrite. (a) α-Ferrite: The solid solution of carbon in α-iron is called α-ferrite or simply ferrite.
What is Fe-Fe3C phase diagram?
In heat treatment processes of steel the very important role plays the Fe-Fe3C phase equilibrium diagram. It enables the selection of the temperature of austenitisation in respect to carbon content in steel as well as to predict the microstructure composition of annealed steel.
What is the phase diagram of iron carbon?
This iron carbon phase diagram is plotted with the carbon concentrations by weight on the X-axis and the temperature scale on the Y-axis. The carbon in iron is an interstitial impurity.
How is the Fe–Ni phase diagram constructed?
The Fe–Ni phase diagram has been constructed by the CALPHAD (CALculation of PHAse Diagram) community , , ,  and reviewed in the ASM handbooks , .
Can we study the martensitic transformation of Fe–Ni alloys?
Also, investigation of the martensitic transformation in the Fe-rich part could benefit from the present study of the magnetism of Fe–Ni alloys (see Ref.  and references therein). The Fe–Ni phase diagram has been constructed by the CALPHAD (CALculation of PHAse Diagram) community , , ,  and reviewed in the ASM handbooks , .
What is the solubility of carbon in fcc Fe?
This phase is a solid solution of carbon in FCC Fe with a maximum solubility of 2.14% C. On further heating, it converts into BCC δ-ferrite at 1395°C. γ-austenite is unstable at temperatures below eutectic temperature (727°C) unless cooled rapidly.