Exam (elaborations)
CWB LEVEL 2 STUDY QUESTIONS REV 1
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CWB LEVEL 2 STUDY QUESTIONS REV 1
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CWB LEVEL 2 STUDY QUESTIONS REV 1''The purpose of the IOI Is to verify that all defects greater than 2% of the plate
thickness have been detected." - Answers-False
"Alloy steels and steels with greater than 0.3% carbon are fully killed." True or false? -
Answers-True
"If the fractured ends of an impact test specimen are examined, it is seen that brittle
specimens breaking with low energy have a flat crystalline fracture showing many shiny
facets." True or false? - Answers-True
"Radiography is not recommended by CSA W59 for fillet welds." - Answers-True
"Since radiography Is a volumetric method the condition of the surface Is not an
Important factor." - Answers-False
"Strain is the extension divided by the original length. "True or false? - Answers-True
"Stress is the load divided by the original cross-sectional area." True or false? -
Answers-True
"The drop weight test is a test for the toughness of the steel and is not used for
measuring toughness of weld metal or the heat affected zone." True or false? -
Answers-True
"The only thing that causes fuzziness at the edge of an image is geometric
unsharpness.'' - Answers-False, fuzziness Is also caused by inherent unsharpness and
scattering
100% C02 is not generally used for GMAW of stainless steels" True or false? - Answers-
True
A 14% Cr martensitic steel heated to 1000°c and air cooled produces - Answers-
martensite
A 60% duty cycle means that the power supply can deliver its rated output for:
A 60% of the rated output only
B. 60% over the rated output followed by 4 minutes at rest
C. 6 minutes at rest followed by 4 minutes at rated output
D. 6 minutes at rated output followed by 4 minutes at rest - Answers-D. 6 minutes at
rated output followed by 4 minutes at rest
A carbon steel component operates satisfactorily at 500°C under a stress of 50MPa.
If 304 stainless were substituted, up to what level could the temperature be raised? -
Answers-600*C
,A conventional diode placed in a circuit allows the passage of current in one direction
only. A silicon controlled rectifier(SCR) operates slightly differently. How does it work?
A. an SCR conducts current in both directions until turned on and current flow is then
prevented
B. an SCR is non-conductive until turned onland then allows current to flow in both
directions
C. an SCR is non-conductive until turned on, allowing current to flow in one direction
only until the flow of current stops - Answers-C. an SCR is non-conductive until turned
on, allowing current to flow in one direction only until the flow of current stops
A dark narrow area 2-3 mm wide appears on a radiograph all the way along the edge of
the area representing the weld. The joint was a 60° double Vee groove. What does this
dark area most likely represent? - Answers-Undercut
A dark, narrow area about 2-3 mm wide appears on a radiograph of a double vee
groove weld along the edge of the area representing the weld. What does this dark area
most likely represent?
A. lack of side wall fusion
B. incomplete penetration
C. undercut
D. slag entrapment - Answers-C. undercut
A radiographic indication 2 to 3 mm wide is observed running along the toe of a double
vee groove weld. Of the choices below, which one is it most likely to be?
A. Weld metal crack
B. Undercut
C. Slag inclusion
D. Lack of side wall fusion
E. Incomplete penetration - Answers-B. Undercut
A radlograph of a groove weld in a 25.4 mm thick dynamically loaded tension member
shows two 6 mm pores with 50 mm between the edges of the pores along the length of
the weld. Is this acceptable to CSA W59-M1989? - Answers-No
A transformer type welding power source without a rectifier outputs what type of
current?
A. direct current
B. alternating current
C. high frequency current
D. pulsed direct current - Answers-B. alternating current
A well-defined line indication with tightly held, heavy powder buildup is likely to
represent
a) Porosity
,b) A sub-surface crack
c) A crack open to the surface - Answers-c) A crack open to the surface
A disadvantage of SCR control is that the output is very 'choppy'. How is the output
made more suitable for welding?
A. the output is smoothed out by the addition of capacitors
B. the large inductor or choke will be added to the circuit
C. the output from an SCR bridge is smooth enough for welding purposes
D. the diodes added to all SCR controlled machines to prevent "choppy" output -
Answers-A. the output is smoothed out by the addition of capacitor
A guided root bend test on a weld would best reveal: - Answers-lack of penetration and
fusion
A liquid that wets a surface is characterized by:
A. No capillary action
B. A small contact angle
C. High density
D. High surface tension
E. Low fluorescence - Answers-B. A small contact angle
According to ASTM E-165, the surface temperature for liquid penetrant inspection
should not be outside the range:
a) 12 to 52C (60 to 125F)
b) 21 to 24C (70 to 75F)
c) -18 to 38C (0 to 100F) - Answers-a) 12 to 52C (60 to 125F)
According to CSA W59 the criteria for evaluating magnetic particle testing are the
sameas those for: - Answers-Radiographic inspection
According to CSA W59 the criteria used for evaluating liquid penetrant testing are the
same as those for:
a) Ultrasonic Inspection
b) Visual inspection
c) Radiographic inspection - Answers-b) Visual inspection
According to CSA W59 the criteria used for evaluating magnetic particle testing are the
same as those for:
a) Ultrasonic inspection
b) Visual Inspection
c) Radiographic Inspection - Answers-c) Radiographic Inspection
According to the radiographic acceptance criteria in CSA W59 what is the maximum
permissible length of cracks?
A. 5 mm
B. 25 mm
, C. Any length
D. It depends on the clearance which is given in a graph
E. Cracks are not permitted - Answers-E. Cracks are not permitted
Acoustic emission relies on detecting very small amounts of mechanical energy
released from such things as growing cracks or
structural discontinuities under load. - Answers-True
Although surfaces should be clean and dry, it is still possible for a yoke to work through
a thin coating of paint. - Answers-True
an A-scan display the vertical displacement of the trace represents:
a) the ampltude of the reflected wave
b) the size of the reflector
c) distance - Answers-a) the ampltude of the reflected wave
An advantage of alliterating current is the ability to detect defects up to 3mm below the
surface. - Answers-False. AC has no depth capacity
An unstabilized stainless steel with 0.15% carbon has been welded. What heat
treatment could be applied to prevent weld decay in service? - Answers-solution
treatment at 1100°C followed by a rapid cool
Approximately what Is the upper limit of human hearing?
a) 15 Hz
b) 15 kHz
c) 15 MHz - Answers-b) 15 kHz
At what point does the carbon content indicate that the material is no longer steel but
cast iron? - Answers-Beyond 1.7%
Basic type flux cored electrodes operate on:
a) DCEP only and give a smooth spray type arc
b) DCEP and DCEN and are characterized by globular transfer
c) DCEN only and are characterized by globular transfer
d) DCEP only and give a rough spray type arc - Answers-b) DCEP and DCEN and are
characterized by globular transfer
Beam spread Is reduced by having a small ratio of wavelength to transducer size. -
Answers-True
Calcium carbonate is an important ingredient in which type of electrodes?
a) cellulose electrodes
b) rutile electrodes
c) basic electrodes
d) oxide electrodes - Answers-c) basic electrodes
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