CWI Nondestructive Examination Methods 4

Question 1

Which NDE method is most effective for detecting subsurface discontinuities in a thick steel weld?

Accepted Answer

Ultrasonic testing

Answer

Ultrasonic testing can detect both surface and subsurface discontinuities at significant depths in steel welds.

Question 2

In ultrasonic testing, what does the term 'dead zone' refer to?

Accepted Answer

Region near the transducer face where near-surface defects cannot be detected

Answer

The dead zone is the region immediately beneath the transducer face where the ringing of the crystal prevents detection of echoes from near-surface reflectors.

Question 3

What is the main advantage of using fluorescent penetrant over visible dye penetrant?

Accepted Answer

Greater sensitivity due to high contrast under UV light

Answer

Fluorescent penetrant produces a bright glow under UV (black) light, providing significantly higher contrast and sensitivity compared to visible dye penetrant.

Question 4

A magnetic particle test is being performed on an austenitic stainless steel weld. Which statement is correct?

Accepted Answer

MT is not applicable because austenitic stainless steel is non-ferromagnetic

Answer

Austenitic stainless steels are non-ferromagnetic and cannot be magnetized, making MT inapplicable.

Question 5

In radiographic testing, which IQI type shows a series of wires of decreasing diameter?

Accepted Answer

Wire-type IQI

Answer

Wire-type IQIs (also called wire penetrameters) consist of a set of wires of different diameters to indicate radiographic sensitivity.

CWI Practice Test

CWI Practice Test

CWI Nondestructive Examination Methods 4