1-38.
1-39.
1-40.
1-41.
1-42.
1-43.
In an electric furnace the
atmosphere is either air or a
controlled mixture of gases.
1.
True
2.
False
Learning Objective: Recognize
how each phase of heat treatment
is produced and controlled and
its effect on the metals being
treated.
What is the primary cause of
distortion and cracking of the
heat-treated part?
1.
Heating the part too slowly
2.
Increasing the soaking
temperature too slowly
3.
Heating one section of the part
more rapidly than the rest of
it
4.
Uneven expansion due to carbon
deposits in the part
When parts are uneven in cross
section, the soaking period is
determined in what manner?
1.
By the total weight
2.
By the largest section
3.
By the lightest section
4.
By the number of parts
What type of medium is normally
used to quench nonferrous metals?
1.
Oil
2.
Brine
3.
Air
4.
Water
Steel must be cooled very slowly in
a medium that does NOT conduct heat
easily in order to produce what
kind of effect?
1.
Maximum softness
2.
Maximum hardness
3.
Maximum ductility
4.
Minimum ductility
Copper becomes hard and brittle
when mechanically worked; but
it can be made soft again by
annealing. To anneal it, you
heat it at temperatures that fall
within what range?
1.
500°F to 600°F
2.
600°F to 700°F
3.
700°F to 900°F
4.
900°F to 1100°F
1-44.
1-45.
1-46.
1-47.
1-48.
1-49.
1-50.
Normalizing is a form of heat
treatment applicable to nonferrous
metals only.
1.
True
2.
False
Which of the following metals
are difficult to harden by heat
treatment?
1.
Wrought iron
2.
Pure iron
3.
Extremely low-carbon steels
4.
All of the above
In plain carbon steel, the maximum
hardness that can be obtained
depends almost completely upon what
factor?
1.
The carbon content of the steel
2.
The thickness of the steel
3.
The heating time
4.
The temperature to which it was
heated
What case-hardening method produces
the hardest surface of any of the
hardening processes?
1.
Carburizing
2.
Halogenizing
3.
Cyaniding
4.
Nitriding
The steel parts are laced in a
container packed with charcoal and
heated in a furnance. Which of the
following case-hardening processes
is being used?
1.
Cementation
2.
Pack hardening
3.
Carburizing
4.
Atmospheric cementation
A slightly oxidizing flame should
be used on what areas of a part
being flame hardened?
1.
Flat surfaces
2.
Corners and grooves
3.
Rounded surfaces
4.
Edges and elongated sections
When flame hardening a steel part,
you move the welding torch at a
certain rate according to which
of the following factors?
1.
Mass of the part
2.
Shape of the part
3.
Depth of the hardness desired
4.
All of the above
4
