NDT Magnetic Particle Testing Methods 4

Question 1

Which type of indication in magnetic particle testing is caused by abrupt changes in cross-section or material permeability rather than a crack?

Accepted Answer

Non-relevant indication

Answer

Non-relevant indications result from geometric features (threads, keyways, changes in cross-section) or permeability variations rather than actual discontinuities requiring rejection.

Question 2

A linear indication in magnetic particle testing is defined as one whose length is:

Accepted Answer

Three times or more its width

Answer

A linear indication has a length-to-width ratio of 3:1 or greater, distinguishing it from rounded indications which have a ratio less than 3:1.

Question 3

What type of discontinuity is most likely indicated by a broad, fuzzy magnetic particle indication?

Accepted Answer

A subsurface discontinuity

Answer

Subsurface discontinuities produce broader, less sharply defined (fuzzy) indications because the leakage field spreads as it reaches the surface above the defect.

Question 4

When evaluating magnetic particle indications, which factor most influences the decision to accept or reject a part?

Accepted Answer

The applicable code, standard, or acceptance criteria

Answer

Acceptance or rejection must be based on the applicable code, standard, or engineering specification that defines allowable indication sizes and types for the specific application.

Question 5

A 'hot crack' or 'crater crack' found in a weld during magnetic particle testing is best described as:

Accepted Answer

A solidification crack occurring in the weld metal during cooling

Answer

Hot cracks (crater cracks) are solidification cracks that form in weld metal as it cools through the solidification temperature range, often found at weld terminations.

NDT - Non-Destructive Testing Practice Test

NDT - Non-Destructive Testing Practice Test

NDT Magnetic Particle Testing Methods 4