Option 46
1. What explains the high electrical and thermal conductivity of metals?
2. How does the structure and properties of the metal change under cold plastic deformation?
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 1.2% C. What is the structure of this
Alloy at room temperature and how such an alloy is called?
4. Draw a diagram of the isothermal transformation of austenite for steel V8. Apply
On it is a curve of the isothermal treatment regime, which provides a hardness of 55 HRC.
Indicate how this regime is called, describe the nature of the transformations and what structure
Is obtained in this case.
5. Forgings of steel 40 have a coarse-grained structure. Using the status diagram
Iron-cementite designate a heat treatment mode for obtaining fine grains and
Explain why the selected mode provides fine-grained steel structure.