Option 37
1. What is a dislocation? Types of dislocations and their influence on mechanical properties
Metal.
2. Strips of lead were rolled at room temperature with varying degrees
Compression ratio: 10. 20, 40, 60%. After rolling, the hardness of all the sheets turned out to be practically
Unchanged. Explain why hardening of lead is not observed during deformation in these
Conditions. What processes are accompanied by deformation of lead at room temperature
Perature?
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 0.01% C. What is the structure
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 a curve of a mode of thermal processing providing hardness 350 НВ. Describe
The essence of transformations and what structure is obtained with this treatment.
5. How does the structure and properties of steel 30 and V11 change as a result of quenching from
Temperatures of 750 and 850 ° C. Explain with the use of the iron-cementite state diagram.
Choose the optimal hardening mode for each steel.