Decision control work number 2 on materials science from the methodology Garbuzova N.E.
Variant 49

Tasks:

1. Select carbon steel for small taps, dies and drills.
Assign a mode of heat treatment, describe the essence of the ongoing transformations,
structure and properties of the tool.
2. As a result of heat treatment, the semiaxes should be obtained over the entire section
Increased strength (hardness 28 ... 35 HRC). For their manufacture, steel 40ХНМА is chosen.
Specify the composition and determine the steel group for the purpose. Assign and justify the mode
thermal treatment, explaining the effect of doping on the transformations occurring at
heat treatment of this steel. Describe the microstructure and properties of products after
heat treatment.
3. For the production of calibres, steel 9X18 is chosen. Specify the composition and determine the steel group
by appointment. Assign a heat treatment mode, give its justification and specify
microstructure and properties of calibers after heat treatment. Explain the purpose of chromium in
of this steel.
4. For the production of some parts of the aircraft, the alloy AL2 is chosen. Bring the chemical
composition and specify the method of manufacturing parts from this alloy. Describe how to improve
mechanical properties of the alloy and the essence of this phenomenon.
5. Advantages and disadvantages of plastics. The use of plastics for die tools.