CHOOSE THE BEST ANSWER 1. Fe-C alloys are classified as steels if: A. The C comp
ID: 1862780 • Letter: C
Question
CHOOSE THE BEST ANSWER
1. Fe-C alloys are classified as steels if:
A. The C composition is equal to 6.69 weight percent.
B. The C composition is equal to 4.30 weight percent.
C. The C composition is between 0.77 and 2.11 weight percent
D. The C composition is below 0.77 weight percent.
E. The C composition is below 2.11weight percent.
2. The Austenite phase in the Fe-C alloy system is:
A. A Fe-C compound with 2.11 weight percent C
B. Pure Fe with the bcc crystal structure
C. Pure Fe with the fcc crystal structure
D. A solid solution of C in Fe with the bcc crystal structure
E. A solid solution of C in Fe with the fcc crystal structure
3. At the eutectoid point of 0.77 weight percent C and 727 degrees C in the Fe-C alloy system:
A. Austenite, ferrite, and graphite are in equilibrium.
B. Austenite, liquid, and graphite are in equilibrium.
C. Ferrite, liquid, and cemenite are in equilibrium.
D. Ferrite, Austenite, and cemenite are in equilibrium.
E. Equilibrium is not reached between any of the phases.
4. Fatigue life of a material is higher if it has,
A. High stiffness and low toughness
B. Pores due to processing
C. High toughness and low hardness
D. Fast crack propagation
E. All of the above
5. Martensite in steel refers to:
A. A Martensite compound
B. A fcc Fe-C solid solution
C. A bcc Fe-C solid solution
D. A tetragonal Fe-C solid solution
E. A hexagonal Fe-C solid solution
6.1) At the composition of 0.77% by weight C, identify the phase(s) present at 950 C
6.2) When the specimen is at 950 C, what is the maximum C composition at which a single phase Austenite is stable?
6.3) If we slowly cool a Fe-C alloy with 0.77% by weight C, austenitized at 950 C, to just below the eutectiod temperature of 727 C, give the weight percentage and composition of the phases present based on the phase diagram given above.
Refer to the Fe-Fe3C phase diagram given below.Explanation / Answer
CHOOSE THE BEST ANSWER 1. Fe-C alloys are classified as steels if: A. The C comp