Certified Welder Weld Inspection and Defects 3

Question 1

Which type of weld crack forms at elevated temperatures during or immediately after solidification of the weld pool?

Accepted Answer

Hot crack (solidification crack)

Answer

Hot cracks, also called solidification cracks, form in the weld metal while it is still at high temperature and the grain boundaries contain liquid films.

Question 2

In ultrasonic testing of welds, the decibel (dB) gain control is used to:

Accepted Answer

Amplify the received signal to compare indications against a reference level

Answer

The dB gain control amplifies echo signals so inspectors can compare discontinuity echoes against calibration reflectors at a standard reference level.

Question 3

Porosity that is distributed uniformly throughout the entire weld is called:

Accepted Answer

Scattered (uniformly distributed) porosity

Answer

Uniformly distributed (scattered) porosity is spread evenly throughout the weld and typically results from consistently contaminated base metal, filler, or shielding.

Question 4

Which factor most increases susceptibility to hydrogen-induced cracking (HIC) in carbon steel welds?

Accepted Answer

High carbon equivalent, high hydrogen, and high restraint

Answer

HIC risk increases with higher carbon equivalent (harder HAZ), higher diffusible hydrogen levels, and higher joint restraint that increases residual stress.

Question 5

A weld profile showing excessive convexity is problematic primarily because it:

Accepted Answer

Creates stress concentration at the weld toes that can initiate fatigue cracks

Answer

An excessively convex weld bead creates sharp toes with high stress concentration, increasing the risk of fatigue crack initiation under cyclic loading.

Certified Welder Practice Test

Certified Welder Practice Test

Certified Welder Weld Inspection and Defects 3