Suggested problems 2

1. For an Fe-0.35C alloy, determine:

the temperature at which AUS first begins to transform on cooling

the primary microconstituent that forms

the temperature at which P forms

2. Estimate the C content of a steel that contains 18% P and 82% primary FE.

Is the steel hypoeutectoid or hypereutectoid?

3. Determine the required transformation temperature for a eutectoid steel to attain the hardnesses:

RC 38 RC 42 RC 52

B = bainite, a pearlite-like constituent

4. Estimate the hardness of a eutectoid steel that has been heated to 800°C for 1 hr, quenched to 650°C and held for 800 sec, and then quenched to room temperature. Describe the microstructure.

5. Describe the microstructure present in a 1050 steel after following heat treatments.

heat at 820°C, quench to 650°C, hold for 90 sec, quench to RT

heat at 820°C and quench to RT

heat at 820°C, quench to 450°C, hold for 90 sec, quench to RT

6. Fine P and a small amount of MAR are found in a quenched 1080 steel. What constituents are present in a 1020 and a 4340 steel, similarly quenched?