Liquid Penetrant Inspection and Magnetic Particle Inspection, Exams of Advanced Education

Download Liquid Penetrant Inspection and Magnetic Particle Inspection and more Exams Advanced Education in PDF only on Docsity!

CWB 2 Module 17 Questions and

Answers

The property of liquids that makes them try to reduce their surface area is known as: A) Capillary action B) Surface tension C) Viscosity - Answer- B) Surface tension True or False? "The ability of a liquid to wet a solid surface can be measured in terms of the contact angle." - Answer- True The phenomenon by which water rises up a narrow tube or by which liquid can penetrate a crack is known as: A) Capillary action B) Surface tension C) Viscosity - Answer- A) Capillary action How must a fluorescent dye be viewed? - Answer- Under a UV (black) light or a mercury vapor light Which of the following penetrants require treatment with a separate agent before the excess can be removed? A) Post-emulsifiable B) Water-washable C) Post-remover D) Solvent-removable - Answer- A) Post-emulsifiable What type of developer is normally used with the solvent-removal process to spot check welds? - Answer- Non-aqueous True or False? "The fluorescent post-emulsified penetrant process is often recommended for high sensitivity applications such as detection of fatigue cracks.: - Answer- True

Does the liquid penetrant process work on stainless steel and aluminum? - Answer- Yes Give one way in which a change to a liquid penetrant procedure could be qualified. - Answer- Use a comparator block to prove you can find the indications True or False? "When using liquid penetrant inspection, the surface must be ground smooth to remove all irregularities before applying the penetrant." - Answer- False According to ASTM E-165, the surface temperature for liquid penetrant inspection should not be outside the range: A) 12°C to 52°C (60°F to 125°F) B) 21°C to 24°C (70°F to 75°F) C) -18°C to 38°C (0°F to 100°F) - Answer- A) 12°C to 52°C (60°F to 125°F) When using the solvent-removeable method, why should the solvent not be sprayed directly on the surface to remove the penetrant? - Answer- It may push penetrant out of discontinuities True or False? "When using post-emulsifiable penetrants, the emulsifier must remain in contact with the surface long enough to mix the excess penetrant but not long enough to reach penetrant in the discontinuities." - Answer- True What could be the effect of spraying on too much developer? - Answer- It could cover up indications What is the difference a false indications and a non-relevant indication? - Answer- False indications are not associated with discontinuities, non-relevant indications are. What is the most likely cause of false indications? - Answer- inadequate pre cleaning or use of lint cloths Which of the following indications is most likely to be cause by a crack? A) Rounded B) Diffused or weak C) Continuous line - Answer- C) Continuous line Which of the following indications is most likely to be cause by porosity? A) Rounded B) Diffused or weak

C) Continuous line - Answer- A) Rounded 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 - Answer- B) Visual inspection True or False? "If a small crack is found by LPI in an aluminum weld, it may be repaired by simply welding over it to melt out the crack." - Answer- False Is there a standard for certifying operators using the liquid penetrant inspection method?

• Answer- Yes, CAN/CGSB 48. The local magnetic field across a crack in a magnetized piece of steel is known as A) Flux leakage B) Saturation C) Induction - Answer- A) Flux leakage The strength of the flux induced when a material is placed in a given magnetic field depends on what property of the material? - Answer- Permeability The level of residual magnetic flux remaining in a ferromagnetic material when an applied field is removed is known as: A) Coercive force B) Saturation C) Retentivity - Answer- C) Retentivity What is the range of applied field (relative to saturation) normally used in magnetic particle inspection? - Answer- 30% - 70% The lines of force in a magnetic field formed by an electric current are: A) Parallel to the direction of the current B) At right angles to the direction of the current - Answer- B) At right angles to the direction of the current The direction of the magnetic field in the centre of a coil is: A) Parallel to the axis of the coil B) At right angles to the axis of the coil - Answer- A) Parallel to the axis of the coil

Which of the following terms might be used to indicate the strength of the magnetic field in a coil? A) Volt/Amp characteristic B) Ampere turns C) B-H curve - Answer- B) Ampere turns True or False? " The the most favourable direction for detecting a crack when using prods is when the crack lies along the line between the prods." - Answer- True When trying to detect a centreline crack in a weld, you would place a yoke: A) Along the weld axis B) Across the weld - Answer- B) Across the weld How are arc strikes avoided when using prods? - Answer- Do not lift prods while applying current What would be a typical current for prods spaced 150mm (6in) apart? - Answer- 600 amps True or False? "An advantage of alternating current is the ability to detect defects up to 3mm below the surface." - Answer- False What advantage does the wet fluorescent particle method have over the dry particle method? - Answer- Sensitivity, the ability to detect small indications True or False? "Although surfaces should be clean and dry, it is still possible for a yoke to work through a thin coating of paint." - Answer- True What weight should an AC yoke be capable of lifting? A) 4.5kg (10lb) B) 45kg (100lb) C) 0.45kg (1lb) - Answer- A) 4.5kg (10lb) What are three changes in a material that could cause a magnetic particle indication in the absence of a discontinuity? - Answer- Work hardening, composition, microstructure, heat treatment

Give one source of non-relevant indications not due to material changes. - Answer- Excessive magnetizing field, residual magnetism 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 - Answer- C) A crack open to the surface 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 - Answer- C) Radiographic inspection Give two applications when demagnetization might be specified. - Answer- If the part will be welded or painted True or False? "A disadvantage of magnetic particle inspection is that it is impossible to obtain any kind of permanent record of the indication." - Answer- False Is there a standard for the certification of operators for magnetic particle inspection? - Answer- Yes, CGSB 48. What is the name of the device that measures the small electrical potential created at right angles to an electric current when placed in a magnetic field. - Answer- Hall detector True or False? "The eddy current technique only works on ferromagnetic material such as steel." - Answer- False What is a typical maximum depth of detection for the eddy current method in non- ferrous metals? A) 6mm B) 35mm C) 0.25mm - Answer- A) 6mm Is there a standard for certifying operators for the eddy current method? - Answer- Yes, CGSB 48.

For what research application has the potential drop method been used? - Answer- Monitoring fatigue crack growth True or False? "If a leak test is done on the pressure vessel, the normal hydrostatic proof test may be omitted." - Answer- False