Garbuzova KR1 Option 04

Garbuzova KR1 Option 04

Option 4
1. Describe the physical nature and mechanism of the crystallization process.
2. What is the purpose of recrystallization annealing? How to assign a mode of this kind
Processing? Give some specific examples.
3. Draw a diagram of the iron-iron carbide state, indicate the structural
Components in all areas of the diagram, describe the transformations and construct a curve
Cooling (using the phase rule) for an alloy containing 0.4% C. What is the structure of this
Alloy at room temperature and how such an alloy is called?
4. Using a diagram of the isothermal transformation of austenite, explain why
It is impossible to obtain a purely martensitic structure in steel when it is cooled at a rate less than
Critical?
5. After the heat treatment of carbon steel, a cementite +
Martensite of tempering. Apply to the state diagram the iron-cementite ordinate of the specified steel
(Approximately) and justify the heating temperature of this steel for quenching. Also indicate the temperature
Describe the transformations that occurred during heat treatment.