Reference no: EM132312964
Visual and Surface Testing Assignment -
Learning Outcomes -
a. Describe the basic mathematical, physical and practical principles of visual, magnetic particle and liquid penetrant testing methods and their advantages and limitations.
b. Describe the structure and properties of various manufactured/processed products and the discontinuities/defects related to them.
c. Report results and interpret/analyse resultant signals and data according to applicable standards.
d. Choose the most appropriate testing system for a particular application according to specification requirements and part considerations.
e. Analyse and solve problems, implementing solutions.
f. Effectively communicate information in digital formats.
Assignment: Please attempt ALL exercises
Exercise 1 -
In the field of aerospace, cracks of 0.1 mm width must be reported. Can unaided normal vision with average viewing conditions detect them? Please state any other assumptions to justify your answer.
A circular corrosion pit of 0.125 mm radius is present on an oil & gas pipeline. Are vision aids required under normal viewing conditions to focus the eye on the flaw? Please state any other assumptions to justify your answer.
If the average eye can resolve the angular separation of two points on a test piece down to 1 minute of arc at 300 mm. What is the resolution in mm at the maximum recommended distance of 600 mm.
Infrared radiation exposures of 200 W/cm2 at 1090 nm for 8 seconds with a continuous-wave glass fibre laser is demonstrated to induce cataract in less than a week. Whereas a similar experiment using 96 W/cm2 for 1 hour has shown no cataract after 1 week. If the first infrared laser intensity was measured at 300 mm, at what distance is considered safe for not developing cataract after 1 week?
Give examples of flaw characteristics that would make a particular type of flaw easier to detect visually.
Give some example characteristics that would complicate visual inspection of a particular type of flaw.
Exercise 2 -
What are the main reasons behind the failure of components?
What are the four primary classifications/stages at which defects may be caused?
Describe in a few sentences how dynamic loading is more likely than static loading to lead to fatigue failure of a component.
Name the indicated discontinuities in the picture (see attached file) that may be found during a manufacturing process and include a short description.
Exercise 3 -
In spite of an optimal magnetisation, it is not possible in some cases to generate the force necessary to form a particle agglomeration.
Describe the condition under which this happens and why it is difficult to detect sub-surface discontinuities using magnetic particle testing? Illustrate your answer with drawings.
Explain what direction of defects is detectable in the figures (see attached file).
Explain how magnetisation is carried out to detect circular and radial defects in circular crowns.
List the content of a Level 1 working instruction for magnetic particle testing. (Hint: while this is a general MPI instruction content, it is NOT a general NDT procedure; make sure you include specific references to MPI).
Exercise 4 -
How would you interpret liquid penetrant indications in the following cases giving decisions on whether to reject the test piece or not?
Cracks in fusion welds.
Forging cracks.
Cracks in sheets or tubing.
Fatigue cracks in turbine blades.
A component made of steel is to be inspected for fatigue cracks using liquid penetrant.
Comment on the time required for different liquid penetrants at different temperatures, the application of the developer and the method of removal. (consult the standards BS EN 3059; EN ISO 3452-3; and EN 571-1).
Refer to equation 15 - Rideal-Washburn to calculate the typical time taken to fill a circular cross section of 200 µm radius void with 2mm depth. Use typical material properties for a high sensitivity post-emulsifier penetrant at 20°C. Note if you use a different value, you should cite your source and/or the type of penetrant.
Comment on the discrepancy between the calculated time and the time typically recommended in the standard.
Attachment:- Assignment File.rar