Option 35
1. What is the essence of the phenomenon of polymorphism and what is its practical significance?
Give an example.
2. How is the recrystallization annealing mode selected? For what purposes is it appointed?
Consider the example of nickel.
3. Draw a diagram of iron-iron carbide, indicate the structural components in
All regions of the diagram, describe the transformations and construct a cooling curve (using
Phase rules) for an alloy containing 1.8% C. What is the structure of this alloy at room temperature
Temperature and how such an alloy is called?
4. Products made of steel 50 are hardened: the first - from the temperature of 740 ° C, and the second - from
Temperature 820 ° C. Using the iron-cementite status diagram, indicate the selected
Temperature and explain which of these products has a higher hardness and better
Operational properties and why.
5. Carbon steel U8 after one type of heat treatment received the structure
Plate perlite, and after another type - granular perlite. What heat treatment was
Applied in the first and second cases?