MIDTERM 3 Study Guide –
 Format for the exam will be a number of Multi-choice/True False questions (3/5 of points) and a choice of 2 of 4
“Major Problems” requiring you to show all your work (2/5 of points).
 As always, read the questions carefully and answer what is asked
 I will be in attendance – if you have questions please ask!
Some sample question from earlier exams (see me for answers!):
1.
A 6.4 mm diameter cylindrical rod fabricated from a Red brass alloy is subjected to reversed tensioncompression load cycling along its axis. If the maximum tensile and compressive loads are +5500 N and -
933 N, determine its fatigue life. a.
5.5 X10 6 b.
20.4 X10 8 c.
11.3 X 10 6 d.
24,500,000 e.
Red brass does not have a fatigue life
2.
For a particular metal part that might be subject to impact loading in sevice (on an earth mover), what would best describe the expected mode of failure, given operating conditions such as Antarctica or
Minneapolis, MN in the month of January? a.
Cup and Cone characteristic b.
Ductile fracture characteristics c.
Brittle fracture characteristics d.
None of these
3.
If the hardness of Cementite is 675 BHN and of Pearlite is 240, determine the expected hardness of a plain carbon steel containing 0.88 wt% C. Assume the mass fractions are good estimates for volume fractions. a.
249 b.
305 c.
280 d.
470 e.
all are high
4.
Using the figure below, The rate of isothermal transportation for 0.76 wt% C in iron at 675

C is most nearly

a.
0.12%/s b.
0.25%/s c.
0.01%/s d.
2.5%/s e.
None of these is close
5.
If a process was deforming a 0.40 wt% C alloy at 950

C , the most likely slip systems that would operate would be (see Fe-C phase diagram below): a.
{321}<-111> b.
{111}<1-10> c.
(110}<-111> d.
{0001}<11-20> e.
None of these
Refer to the segment of the Fe-C Phase diagram below for the questions following it.
6.
The composition sketch as x-x’ is commonly called the _______ : a.
Eutectic composition b.
Intermetallic composition c.
Peritectic composition d.
e.
Eutectoid composition
ProFerrite composition
7.
For a composition of 0.25 wt% C at 20

C, the total amount of cementite present is most nearly: f.
6.25% g.
5.41% h.
12.8% i.
3.62% j.
None of these is close

Reference the Fe-C Phase Diagram seen here for the 3 questions below it: a

8.
The point shown as “a” in the Fe-C phase diagram is most commonly called the: a.
Peritectic Point b.
Eutectic Point c.
Eutectoid Point d.
Single Phase Point e.
None of these
9.
At the temperature of 1200

C at a composition of 3 wt% (11.5 at%) C, determine the phases present: a.
Pearlite and Cementite b.
Austenite and Cementite c.
Austenite and Ferrite d.
Ferrite and Liquid e.
Liquid and Austenite
10.
For this same composition (3 wt% C), at a temperature of 800

C, determine the quantity of cementite that would be present? a.
35.1% b.
64.9% c.
37.7% d.
6.7% e.
1.0%

11.
For the given steel alloy designation numbers, state the carbon wt % of each alloy: a.
4140 ____________ wt% carbon b.
52100 ____________ wt% carbon c.
1008 ____________ wt% carbon d.
8620 ____________ wt% carbon
12.
During steelmaking, conducted at a temperature of about 1800

C, determine the prevailing microstructure of the refractory materials used in the steelmaking furnace (at this temperature) if they are nominally 40% Al2O3 and the remainder MgO.

This is but of a sampling of what to expect – you can expect questions on Heat treatment (phase transformation using IT or CT diagrams) and precipitation hardening ideas as well. Of course make sure that you try the homework problems from Ch 8, 9, 10 and 11.
Good Luck – see you at 3PM Friday