Examination number 2 on materials. Option number 32
Question 1. Give the comparative characteristic of the normal and the isothermal hardening. Describe the nature of transformations occurring in these types of thermal treatment. Give specific examples, describe the structure and properties.
Question 2: With the phase diagram of the iron-cementite determine the temperature normalization, annealing and quenching the steel U8A. Give graphically characterize these types of heat treatment and describe the structure and properties of steel after each treatment regimen.
Question 3: Using the values of the critical points and the curve of hardness
depending on the annealing temperature, set for alloy steel 40KhN temperature quenching and tempering temperature necessary to ensure the hardness of 30 HRC. Specify the composition of the group and determine the steel for its intended purpose, assign and justify the regime of thermal treatment, explaining the effect of doping on the transformations occurring
by heat treatment of the steel. Describe the structure and properties of the products in the finished form.