Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2A2-5: Testing of Metals > Objective 06: Magnetic Particle Inspection > Flashcards

Objective 06: Magnetic Particle Inspection Flashcards

1
Q

What is Magnetic Particle Inspection?

A

Detection of cracks present at the surface of a component made from ferromagnetic material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What kind of ferromagnetic material is Magnetic Particle Inspection used on?

A
  1. Cast Irons
  2. Carbon Steel
  3. All kinds of Steel Alloys (with the exception of austenitic steels)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Magnetic Particle Inspection based on?

A

The faces of a crack tend to form north and south poles if a magnetic flux is established in the component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is flux induced in ferromagnetic material for Magnetic Particle Inspection?

A
  1. Permanent magnet or electromagnet causing current flow through the component
  2. Wrapping coils around it and then passing a current through a coil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is either dry iron powder or iron powder in a liquid suspension used to reveal cracks for Magnetic Particle Inspection?

A

If the system is so arranged that the crack interrupts the flux lines, the particles of iron are attracted to the poles formed at the crack, which is delineated as a black line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of transformer is used to supply the necessary flux when searching for surface defects?

A

AC Transformers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What type of transformer is used to supply the necessary flux below the surface of the material when searching for subsurface defects to a depth of approximately 4 mm?

A

DC Transformers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are 4 different areas of Magnetic Particle Procedures?

A
  1. Magnetic Particles
  2. Surface Conditioning
  3. Examination Techniques
  4. Acceptance Criteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the types of Magnetic Particles that may be used in Magnetic Particle Testing?

A
  1. Dry
  2. Wet
  3. Fluorescent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Does the procedure used differ based on Magnetic Particle type in Magnetic Particle Testing?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What kind of light is used with Fluorescent Particles in Magnetic Particle Testing?

A

Ultraviolet Light (black light) in a darkened area with an intensity of 1000 microW/cm2 at the surface of the part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is it ensured that the intensity of lighting used for Magnetic Particle Testing is correct?

A

A black light meter is used at least once every 8 hours and whenever the work station is changed. Records of the intensity measurements and frequency for subsequent audit verifications are maintained.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the preparation that directly preceeds Magnetic Particle Testing with black light?

A

There is a warm-up period of 5 minutes. The inspector must be in the darkened area for 5 minutes before starting the examination to enable the inspector’s eyes to adapt to dark viewing. Photosensitive eyeglass lenses are not permitted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When is Surface Conditioning required for Magnetic Particle Testing?

A

If the surface irregularities can mask indications

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is Surface Conditioning performed before Magnetic Particle Testing occurs?

A

The surface and adjacent areas within 25 mm are cleaned with any suitable means to ensure removal of extraneous materials that can interfere with the examination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How many examinations are perfomed on each test area for Magnetic Particle Testing?

A

At least 2 seperate examinations

17
Q

How does the second examination compare to the first in Magnetic Particle Testing?

A

The lines of flux used are perpendicular

18
Q

To be effective, what is important to ensure when conducting multiple examinations in Magnetic Particle Testing?

A

They are conducted with sufficient overlap to ensure 100% coverage

19
Q

What are 5 magnetization techniques that can be used on ferromagnetic materials to detect cracks and other discontinuities on or near the surface of the material?

A
  1. Prod
  2. Longitudinal
  3. Circular (direct contact and central conductor methods)
  4. Yoke
  5. Multidirectional
20
Q

How does the Prod Technique work for Magnetic Particle Testing?

A

It uses portable prod contacts pressed against the test surface in the area to be examined

21
Q

What caution should be taken with the Prod Technique for Magnetic Particle Testing?

A

Arcing must be prevented because the heat produced can create local hard spots that can cause service problems

22
Q

How does the Longitudinal Magnetization Technique work for Magnetic Particle Testing?

A

Coils are wrapped around the surface being examined and the current passing though them produces a longitudinal magnetic field parallel to the axis of the coil

23
Q

What determines the required field strength of the coils used in the Longitudinal Magnetization Technique for Magnetic Particle Testing?

A

The length to diameter ratio of the part being examined

24
Q

What kind of cracks are revealed by the Logitudinal Magnetization Technique for Magnetic Particle Testing?

A

Transverse cracks

25
Q

How does Circular Magnetization Direct Contact Method work for Magnetic Particle Testing?

A
  1. Contact electrodes introduce the current into the test piece which behaves like a current carrying conductor
  2. A circular shaped magnetic field is established perpendicular to the test piece
  3. Stray fields develop across defects lying in the same direction as the connecting line between the current contacts, thus revealing cracks
26
Q

What types of parts is the Circular Magnetization Direct Contact Method used to test for Magnetic Particle Testing?

A

Small parts with no openings through the interior

27
Q

What kind of cracks are revealed by the Circular Magnetization Direct Contact Method for Magnetic Particle Testing?

A

Longitudinal Cracks

28
Q

How does Circular Magnetization Central Conductor Method work for Magnetic Particle Testing?

A
  1. With tube or ring-shaped parts, magnetization is achieved without contact using a current carrying conductor
  2. The test piece is surrouded by the circular magnetic field
29
Q

What kinds of cracks are revealed by Circular Magnetization Central Conductor Method?

A
  1. Longitudinal Cracks

2. Star-shaped Cracks running from the centre to the outside of the plane surfaces

30
Q

How does Electromagnetic Yoke Technique work for Magnetic Particle Testing?

A
  1. A magnetic field from a coil system is generated over the pole of a soft iron core and then transmitted into the test object
  2. The iron core and the workpiece form a closed magnetic circuit
  3. The magnetic field lines flow in the test piece in a direct connection line between the poles
31
Q

What kind of crack is revealed by Electromagnetic Yoke Technique for Magnetic Particle Testing?

A

Transverse Cracks

32
Q

How does Multidirectional Magnetization Technique work for Magnetic Particle Testing?

A

Using high amperage power packs operating up to 3 circuits, the circuits energize one at a time in rapid succession producing an overall magnetization of the part in multiple directions

33
Q

How many processing steps does Multidirectional Magnetization Techniques require for Magnetic Particle Testing?

A

1

34
Q

What is a typical Test Procedure for Magnetic Particle Testing?

A
  1. Observe guidelines as per Code of Constrution
  2. Preparation of the test part, e.g. cleaning, degreasing, descaling, rust removal
  3. Visual examination of readily apparent cracks or other surface conditions
  4. Check inspection conditions (ambient light, UV light intensity)
  5. Measure the applied magnetic field, in turn adjusting for the appropriate magnetic field intensity
  6. Clamp the material to be inspected or apply hand yoke magnet
  7. Switch on the magnetizing field
  8. Spray the part with the test medium containing the magnetic particles
  9. Switch ff the magnetizing field
  10. Visually evaluate the surface for defect indications
  11. Repeat #5 to #10 at 90º to original test orientation
  12. Demagnetize the part (if required)
  13. Document the indications (positions, size, number, orientation)
  14. Classify the inspected part (acceptable, reject, possible rework)

2A2-5: Testing of Metals (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions