11 NDT

Question 1

1. Describe the steps involved in a dye penetrant inspection.

Answer 1

The surface is cleaned and then penetrant is applied and allowed to dwell for a specified time. The penetrant is then removed with an emulsifier or cleaner. Once removed, the part is dried and then developer is applied. The results are then inspected and interpreted.

Question 2

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

Answer 2

A magnifying glass, flashlight, mirror, and borescope.

Question 3

3. What are some of the NDT methods that may be used on aluminum parts?

Answer 3

Visual, dye penetrant, eddy current, ultrasonic testing and radiography.

Question 4

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

5. A correctly made butt weld will have what bead width and how much penetration?

Answer 5

The bead width should be 3 to 5 times the thickness of the base metal and there must be 100% penetration.

Question 6

6. What telltale characteristics are evidence of a cold weld?

Answer 6

A cold weld has rough, irregular edges that are not feathered into the base metal and has variations in penetration amounts.

Question 7

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

Answer 7

25-50%

Question 8

8. Describe the basic steps for conducting a magnetic particle inspection.

Answer 8

Magnetize the part, then coat the surface with ferromagnetic particles. If a defect or discontinuity is present, the particles align with the discontinuity forming a visible pattern.