CWS CWS Weld Inspection & Testing

Question 1

Which nondestructive testing (NDT) method uses high-frequency sound waves to detect internal weld discontinuities?

Accepted Answer

Ultrasonic testing

Answer

Ultrasonic testing (UT) transmits high-frequency sound waves into a weld to detect internal flaws such as porosity, cracks, and incomplete fusion.

Question 2

According to AWS D1.1, what is the minimum preheat temperature required for ASTM A36 steel greater than 1.5 inches thick?

Accepted Answer

150°F (66°C)

Answer

AWS D1.1 requires a minimum preheat of 150°F for A36 steel over 1.5 inches thick to prevent hydrogen-induced cracking.

Question 3

A CWS notices undercut along the toe of a fillet weld. What is the most common cause of this discontinuity?

Accepted Answer

Excessive travel speed

Answer

Excessive travel speed causes the weld pool to lag, producing undercut at the weld toe as the arc erodes base metal without sufficient fill.

Question 4

Which weld discontinuity is characterized by a fold of metal that has been rolled or forged into the surface but is not fused to the base metal?

Accepted Answer

Overlap

Answer

Overlap is a protrusion of weld metal beyond the weld toe, lying on the base metal without fusing to it.

Question 5

When performing a macro examination of a weld cross-section, which etchant is most commonly used for carbon steel welds?

Accepted Answer

Nital (nitric acid in alcohol)

Answer

Nital (2–5% nitric acid in ethanol) is the standard etchant for revealing weld macro structure, HAZ boundaries, and fusion lines in carbon steel.

CWS - Certified Welding Supervisor Practice Test