Q1: Which of the following is not found in iron-carbon equilibrium diagram ?

ANS:A - Curie point

The "Curie point" is not found in the iron-carbon equilibrium diagram. Explanation:

1. Iron-Carbon Equilibrium Diagram: The iron-carbon equilibrium diagram, also known as the iron-carbon phase diagram or the Fe-C phase diagram, illustrates the phases and phase transformations that occur in iron-carbon alloys as a function of temperature and composition.
2. Key Points on the Diagram:
   • Eutectic Point: The eutectic point represents the composition and temperature at which liquid phase transforms into two solid phases (α-ferrite and cementite) during cooling.
   • Eutectoid Point: The eutectoid point represents the composition and temperature at which one solid phase (austenite) transforms into two different solid phases (α-ferrite and cementite) during cooling.
   • Peritectic Point: The peritectic point represents the composition and temperature at which liquid phase reacts with a solid phase to form a new solid phase. It is a less common feature of the iron-carbon equilibrium diagram.
   • Curie Point: The Curie point, also known as the Curie temperature, is the temperature at which a ferromagnetic material loses its ferromagnetic properties and becomes paramagnetic. It is not a feature of the iron-carbon equilibrium diagram because it relates to magnetic properties rather than phase transformations.
3. Curie Point: The Curie point is an important property of ferromagnetic materials such as iron and steel. Above the Curie point, ferromagnetic materials lose their permanent magnetic properties and become paramagnetic. The Curie point is influenced by factors such as composition, crystal structure, and magnetic domain orientation.
4. Conclusion: Among the options provided, the Curie point is not found in the iron-carbon equilibrium diagram. The other points listed (eutectic point, eutectoid point, and peritectic point) are features that can be observed on the iron-carbon equilibrium diagram, representing specific phase transformations and compositions in iron-carbon alloys.