Garbuzova KR2 Option 23

1. Spring made of steel 75 after properly tempered and tempered
Has a hardness significantly higher than that stipulated by the technical conditions. Than
Is this defect caused and how can it be corrected? Specify the structure and firmness that
High elastic properties of the springs.
2. Steel P9F5 was chosen for making machine taps and dies. Specify the composition;
Designate and justify the heat treatment regime, explaining the effect of alloying elements on
Transformations occurring at all stages of heat treatment. Describe the microstructure and
Properties of steel after heat treatment.
3. For the manufacture of power blades of aviation gas turbines, an alloy
XH77TUP (EI437B). Specify the composition and determine the alloy group for the intended purpose. Assign Mode
Heat treatment and describe the effect of temperature on the characteristics of heat resistance of this
Alloy in comparison with heat-resistant steels.
4. For the manufacture of a number of parts in shipbuilding, brass LO70-1 is used. Please specify
Composition and describe the structure of the alloy. Give a general characteristic of mechanical properties
Alloy and the reasons for introducing tin into this brass.
5. Describe the polar thermoplastic plastics (polyamides, penton, polycarbonates
and etc.). Their composition, properties and scope.