Chapter Nine Exam Flashcards
When trying to detect a solidification crack in a weld you should place a yoke:
Across the weld.
Which of the following techniques is most likely to detect a longitudinal crack lying along the fusion boundary of a weld at the surface?
AC yoke across the weld
The lines of force in a magnetic field formed by an electric current
saturate and create magnetic field NO. Parallel to direction of current?
The procedure of decreasing the strength of the magnetic field is
Demag
Why do codes and specifications prohibit the use of prods?
Potential for arc strikes.
Magnetic particle inspection of cast iron requires a stronger magnetic field than structural steels because:
Permeability is lower.
Can MPI be used as inspection tool to find discontinuities in ferritic stainless steel?
No it is non magnetic. NO Only if sigma phase is achieved?
Magnetic particles are attracted to indications because the:
indications are at a location of flux leakage.
The level of residual magnetic flux remaining in a ferromagnetic material when an applied field is removed is known as:
Retentivity.
The value of the applied field (H) to bring down the residual value of flux (B) to zero is called the:
Coercive force.
What is the direction of the magnetic field in the centre of a short current carrying coil?
Concentric with the coil.No maybe 90 degrees to flow of current.
Why is it necessary to have a dwell time in the application of penetrant testing?
Time it takes for penetrant to enter cavity.
Which of the following defects cannot be detected with LPI?
Lamellar tearing at the root of the weld joint.
Which organization stipulates the requirements for qualification of NDE personnel in Canada?
Natural resources Canada. No. CGSB?
An indication appearing at the toe of a weld not due to any known defect is a:
False indication
Which of the following statements is true regarding using LPI method to check welds with a high interpass temperature?
Penetrants evaporate on hot welds
How is the excess penetrant removed when portable solvent-removable LPI method is performed?
Wipe away excess with clean cloth that spray solvent on rag and wipe.
The property of liquids that makes them try to reduce their surface area is known as:
Surface tension
The speed of the penetrant filling a void is determined by the:
Viscosity.
To properly evaluate an indication using the liquid penetrant inspection method, the inspector must know the
test procedures and techiniques.
What position(s) can dye penetrant testing be used?
All positions
Eddy current is used to inspect:
All above
When using potential drop inspection, the measured value of the drop will:
Increase with increasing discontinuity size.
The most sensitive leak testing method utilizes:
Low pressure air with a helium tracer.
