Complete answers are given to 5 questions 24 variants of the 2 control work on materials science according to the methodology of Garbuzovoy N.E.
1. Indicate temperatures at which the process of solid nitriding is carried out. Explain why nitriding is not performed at temperatures below 500 and above 700 ° C (using the iron-nitrogen state diagram). Name the grades of steels used for azotirovaniya, and describe the full cycle of their thermal and chemical-thermal treatment.
2. For the manufacture of stamps, steel 6XC is chosen. Specify the composition and determine the steel group for the purpose. Assign a heat treatment mode, give its justification. Describe the microstructure and properties of steel after heat treatment.
3. Assign a grade of heat-resistant steel (silchrom) for valves of automobile engines of low power. Specify the composition, assign and justify the mode of heat treatment of steel. Describe the microstructure and the main properties of the steel after heat treatment.
4. BrBNT-1,7 bronze was chosen for manufacturing current-conducting elastic elements. Give the chemical composition, heat treatment and the resulting mechanical properties of the alloy. Describe the processes that occur during thermal processing, and explain the nature of hardening in connection with the copper-beryllium state diagram.
5. Give the characteristics of the mechanical and technological properties of glass fibers and fiberglass. Indicate the scope of their application in engineering.