CWB Welding Inspector Level 3 Exam Updated
Study Guide Questions and Answers (2026) |
Focused Revision Pack | Grade A+
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the free energy of oxide formation against temperature.
(c) shows the rate of oxidation of metals against temperature. -✓✓(b)
True or False?
A metal with a high negative free energy of oxide formation will generally require greater
shielding from the atmosphere during welding. -✓✓True
Electricity can be conducted by:
(a) atoms and electrons.
(b) electrons and ions.
(c) only ions. -✓✓(b)
Which of the following elements is often present in submerged arc fluxes to improve arc
stability?
(a) copper
(b) potassium
(c) nickel
(d) tungsten -✓✓(b)
Thoria is added to tunsten electrodes for what purpose? -✓✓To increase thermionic
emission by lowering the work function.
True or False?
All pure metals have the same crystal structure. -✓✓False. Metals generally have one of
three basic structures.
Which crystal structure(s) is (are) composed of close-packed planes? -✓✓FCC and
HCP
The real strength of metals is lower than the theoretical value because:
(a) real crystals always fracture along specific crystal planes.
(b) grain boundary sliding occurs.
(c) the presence of dislocations facilitates slip. -✓✓(c)
Multiplication and subsequent congestion of moving dislocations causes:
(a) elastic extension.
(b) work or strain hardening.
, (c) a drop in the yield stress. -✓✓(b)
Which of the following elements are most likely to form interstitial solid solutions?
(a) copper
(b) nickel
(c) carbon -✓✓(c)
If FCC iron has a denser structure than BCC iron, why does it have a higher solubility
for carbon? -✓✓The preferred site for carbon in BCC iron is smaller than that in FCC
iron.
If two metals have complete mutual solid solubility how many phases are formed in the
solid- one or two? -✓✓One
How many phases are there in a eutectic- one or two? -✓✓Two
Without referring to the text, draw the phase diagram for a eutectic system with limited
mutual solid solubility of the two components. -✓✓Refer to Figure 6.6(Module 20-2014,
page 18)
Using the portion of the iron-carbon phase diagram in Figure 6.10(Module 20-2014,
page 21), use the lever rule to determine the precentage of ferrite and eutectoid pearlite
present in a slowly cooled 0.2% carbon steel. -✓✓About 25% pearlite and 75% ferrite.
Here the tie line begins at 0.0%C (α ferrite) and ends at 0.08%C (pearlite).
The fulcrum for the lever rule is at 0.2%C
% pearlite = (0.2%C - 0.0%C)/).8%C - 0.0%C) x 100%
% pearlite = (0.2/0.8) x 100%
% pearlite = 25%
Which of the following metals has the highest work hardening coefficient?
(a) 70/30 brass
(b) aluminum
(c) copper
(d) low carbon steel -✓✓(a)
True or False?
Recrystallization always involves the formation of a new phase. -✓✓False
To get recovery and recrystallization the metal must have been previously
(a) quenched.
(b) heated.
(c) cold worked. -✓✓(c)
Can strain aging in low carbon steels take place at room temperature? -✓✓Yes
Study Guide Questions and Answers (2026) |
Focused Revision Pack | Grade A+
The Ellingham diagram
(a) is a plot of thermal conductivity against temperature,
(b) shows the free energy of oxide formation against temperature.
(c) shows the rate of oxidation of metals against temperature. -✓✓(b)
True or False?
A metal with a high negative free energy of oxide formation will generally require greater
shielding from the atmosphere during welding. -✓✓True
Electricity can be conducted by:
(a) atoms and electrons.
(b) electrons and ions.
(c) only ions. -✓✓(b)
Which of the following elements is often present in submerged arc fluxes to improve arc
stability?
(a) copper
(b) potassium
(c) nickel
(d) tungsten -✓✓(b)
Thoria is added to tunsten electrodes for what purpose? -✓✓To increase thermionic
emission by lowering the work function.
True or False?
All pure metals have the same crystal structure. -✓✓False. Metals generally have one of
three basic structures.
Which crystal structure(s) is (are) composed of close-packed planes? -✓✓FCC and
HCP
The real strength of metals is lower than the theoretical value because:
(a) real crystals always fracture along specific crystal planes.
(b) grain boundary sliding occurs.
(c) the presence of dislocations facilitates slip. -✓✓(c)
Multiplication and subsequent congestion of moving dislocations causes:
(a) elastic extension.
(b) work or strain hardening.
, (c) a drop in the yield stress. -✓✓(b)
Which of the following elements are most likely to form interstitial solid solutions?
(a) copper
(b) nickel
(c) carbon -✓✓(c)
If FCC iron has a denser structure than BCC iron, why does it have a higher solubility
for carbon? -✓✓The preferred site for carbon in BCC iron is smaller than that in FCC
iron.
If two metals have complete mutual solid solubility how many phases are formed in the
solid- one or two? -✓✓One
How many phases are there in a eutectic- one or two? -✓✓Two
Without referring to the text, draw the phase diagram for a eutectic system with limited
mutual solid solubility of the two components. -✓✓Refer to Figure 6.6(Module 20-2014,
page 18)
Using the portion of the iron-carbon phase diagram in Figure 6.10(Module 20-2014,
page 21), use the lever rule to determine the precentage of ferrite and eutectoid pearlite
present in a slowly cooled 0.2% carbon steel. -✓✓About 25% pearlite and 75% ferrite.
Here the tie line begins at 0.0%C (α ferrite) and ends at 0.08%C (pearlite).
The fulcrum for the lever rule is at 0.2%C
% pearlite = (0.2%C - 0.0%C)/).8%C - 0.0%C) x 100%
% pearlite = (0.2/0.8) x 100%
% pearlite = 25%
Which of the following metals has the highest work hardening coefficient?
(a) 70/30 brass
(b) aluminum
(c) copper
(d) low carbon steel -✓✓(a)
True or False?
Recrystallization always involves the formation of a new phase. -✓✓False
To get recovery and recrystallization the metal must have been previously
(a) quenched.
(b) heated.
(c) cold worked. -✓✓(c)
Can strain aging in low carbon steels take place at room temperature? -✓✓Yes
