Variant 47

1. What are the advantages and disadvantages of surface hardening of steel
Products when heated by high-frequency currents compared with hardening by cementation?
Name the steel grades used for these treatments.

2. Steel B1 is chosen for the manufacture of hacksaws for metal. Decipher the composition and
Determine the steel group according to its intended use. Assign a heat treatment mode, bring it
Justification, explaining the effect of doping on the transformations occurring during thermal
Processing of hacksaws. Describe the structure and properties of steel after heat treatment.

3. For the manufacture of high-strength parts, martensitic-aging steel is used
H18K8MZ. Decipher the composition and specify the steel group for the intended purpose. Assign and justify
Mode of heat treatment, explaining the effect of alloying elements on the transformation,
Occurring during heat treatment. Describe the structure, properties and nature of hardening
become.

4. AMg3 alloy is selected for the manufacture of some parts of the aircraft. Specify the composition and
Describe the method of hardening of this alloy, explaining the nature of hardening. Give
Characteristics of the mechanical properties of the alloy.

5. Indicate the composition and properties of ceramics used in electrical instrumentation.