Option 27
1. Describe the phenomenon of polymorphism in the application to zirconium. Draw the elementary
Crystalline cells, specify their parameters and coordination number.
2. What is the essence of the work hardening and how does it have practical use?
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 1.1% C. What is the structure of this
Alloy at room temperature and how such an alloy is called?
4. What is the difference between the carburizing process in a solid carburizer from the gas
Carburization? How can we fix the coarse-grained structure of overheating of cemented
Products?
5. The gears of steel 45 are hardened: the first - from the temperature of 740 ° C, and the second - from 820 ° C.
Using the iron-cementite state diagram, apply the selected heating temperatures and
Explain which of these gears has a higher hardness and better performance
Properties and why.