KR materials science. Option 16 (5 tasks)

OPTION number 16 Task number 1. To develop a technology for the process of thermal or chemical-thermal treatment for a part or tool made of the specified steel, a cutting die, indicate the nature of the work of this part; indicate the chemical composition of the selected grade of steel (alloy) according to GOST; to compile a map of successive heat treatment operations, including hardening temperature, tempering temperature, temperature of chemical treatment, time spent on them, cooling medium. Task number 2. Draw a state diagram of iron iron carbide, indicate the structural components in all areas of the diagram, for a given alloy at a given temperature, determine the number of phases according to the rule of segments, construct cooling or heating curves with the number of degrees of freedom indicated by the phase rule and indicate on the cooling or heating curve the phases that formed in areas. Heating curve; temperature range 0 16000С; the amount of carbon is 2.8%; temperature is 7800C. Task number 3. Draw a diagram of the isothermal transformation of austenite for hypoeutectoid steel. Put on it a curve of the isothermal treatment mode, providing the specified hardness 55 57HRC. Indicate what this mode is called, describe the essence of the transformations and what structure is obtained in this case. Task number 4. To develop hardening technology for the ML5 alloy. indicate the composition, mechanical properties, structure; indicate the details that can be made of this alloy. Task number 5. Assign a brand of non-ferrous alloy for the manufacture of rolling bearings. a) decipher the composition of the alloy and determine which group (by designation) this alloy belongs to; c) describe the effect of alloying elements on the main characteristics of the alloy and the reasons for choosing this alloy.