14-50.
At ordinary temperatures, the
carbon in steel exists in the form
of iron carbide particles.
These
particles are known by what name?
1.
Cordite
2.
Ferrite
3.
Pearlite
4.
Austenite
14-51.
In the heat-treatment process of
steel, the element that normally
has the greatest influence is
silicon.
True
False
IN ANSWERING QUESTION 14-52, REFER TO
TABLE 15-1 IN THE TEXTBOOK.
14-52.
14-53.
14-54.
14-55.
What color is steel at 1,825°F?
1.
Lemon
2.
Salmon
3.
Orange
4.
Light lemon
When water is used as a quenching
medium for steel, the water bath
should be held at what prescribed
temperature?
1.
32°F
2.
48°F
3.
55°F
4.
65°F
When steel is heated above its
critical temperature and then
slowly cooled, what is the final
product called?
Sorbite
Pearlite
Troostite
Martensite
After welding a ferrous metal, you
should use the normalizing process
of heat treatment for what reason?
1.
To reduce its carbon content
2.
To induce internal stresses
3.
To remove all strains
4.
To make it harder
14-56.
Which of the following carburizing
14-57.
14-58.
14-59.
methods produces only a thin case?
Pack
Gaseous
Nitriding
Cyaniding
What prescribed temperature is
required for nitriding steel
parts?
1.
950°F
2.
l,150°F
3.
1,300°F
4.
1,400°F
Aluminum alloys should be heated
by the use of which of the
following methods?
An air furnace
A molten salt bath only
An electric furnace only
A molten salt bath or an
electric furnace
When a nonferrous part is
quenched, what is the maximum
recommended time between the
part’s removal from the heat and
immersion?
1.
10 sec
2.
15 sec
3.
20 sec
4.
25 sec
14-60.
When annealing an aluminum part in
a salt bath, you should use equal
parts of which of the following
chemicals?
1.
Epsom salt and sodium nitrate
2.
Epsom salt and silver nitrate
3.
Potassium nitrate and baking
soda
4.
Potassium nitrate and sodium
nitrate
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