2. What are 3 applications for martensitic steels?
3. What is a typical yield strength value for an annealed or normalized 1018 (or 1020) steel alloy? What is a typical yield strength for a water-quenched or oil-quenched 1045 (or 1040 or 4140 or 4130) steel? What is the % difference in the strengths for these two materials? (Provide references for your property data)
4. For the following Fe-C alloys, what phases are present, what are the compositions of each phase, and what are the relative fractions of each phase? Assume slow cooling or heating. Draw the microstructure.
a. Fe-1.5 w/o C at 800°C
b. Fe-1.0 w/o C at 1000°C
c. Fe-1.5 w/o C at 400°C
5. After being slowly cooled slowly from the austenite region, a plain carbon steel exhibits a microstructure consisting of 40 percent pearlite and 60 percent ferrite.
a. Estimate the carbon content of the steel.
b. Describe the equilibrium microstructure that would be obtained if the steel were heated to 730°C and held there for a long period of time.
c. What would the equilibrium microstructure be if this steel were heated to 850°C.
d. Make sketches of each of these three microstructures.
6. A Fe-0.25 w/o C alloy is slowly cooled to 700°C. What is the composition of the ferrite (α) phase and what is the composition of the cementite (Fe3C) phase? What are the relative fractions of α and Fe3C? What are the relative fractions of the proeutectoid-α and pearlite constituents?