Garbuzova KR1 Option 02

Option 2
1. How and why does the cooling rate during crystallization affect the structure of the ingot?
2. From a sheet of lead by rolling at room temperature, a thin
foil. The hardness and strength of this foil turned out to be the same as that of the original sheet.
Explain what processes occurred during plastic deformation of lead and what
Changes in structure and properties were accompanied.
3. Draw a state diagram of iron-iron carbide, indicate the structural
Components in all areas of the diagram, describe the transformations and construct a curve
Cooling (using a phase rule) for an alloy containing 0.8% C. What is the structure of this
Alloy at room temperature and how such an alloy is called?
4. Using the state diagram iron-iron carbide and the hardness change curve in
Depending on tempering temperature, assign a hardening temperature for carbon steel 40 and
Tempering temperature required to provide a hardness of 400 HB. Describe the transformation into
All stages of heat treatment and the resulting structure.
5. For what purposes is diffusion annealing applied? How is the mode of such
Annealing? Give examples.