Nondestructive Testing

Question 1

Describe the steps involved in a dye penetrant inspection.

Answer 1

The surface is cleaned.

Penetrant is applied and allowed to dwell for a specified time.

Penetrant is removed with an emulsifier or cleaner.

Part is dried and developer is applied.

Results are inspected and interpreted.

Question 2

Name some tools that are commonly used to assist in making visual inspections of welds.

Answer 2

Magnifying glass.
Flashlight.
Mirror.
Borescope.

Question 3

What are some of the nondestructive testing methods that may be used on aluminum parts?

Answer 3

Visual.
Dye penetrant.
Eddy current.
Ultrasonic testing.
Radiography.

Question 4

What process occurs during the preparation stage of a dye penetrant inspection when the penetrating liquid is applied and then removed from a cracked part?

Answer 4

The penetrant enters the crack by capillary action, and remains there until made visible by the developer.

Question 5

A correctly made butt weld will have what bead width? How much penetration?

Answer 5

Bead width should be 3 to 5 times the thickness of the base metal.
There must be 100% penetration.

Question 6

What telltale characteristics are evidence of a cold weld?

Answer 6

Rough, irregular edges that are not feathered into the base metal.
Variations in penetration amounts.

Question 7

The penetration of a fillet weld should be what percentage of the thickness of the base metal?

Answer 7

25 to 50%

Question 8

Describe the basic steps for conducting a magnetic particle inspection.

Answer 8

Magnetize the part.
Coat the surface with ferromagnetic particles.

If a defect is present, the particles align with the discontinuity forming a visible pattern.