CWI Fundamentals 2

Question 1

Which welding process uses a non-consumable tungsten electrode and a separate filler metal?

Accepted Answer

GTAW

Answer

GTAW (Gas Tungsten Arc Welding) uses a non-consumable tungsten electrode; filler metal is added separately if needed.

Question 2

What does the term 'heat-affected zone' (HAZ) refer to in welding?

Accepted Answer

The base metal area altered by heat but not melted

Answer

The HAZ is the portion of the base metal whose properties have been altered by welding heat without actually melting.

Question 3

A CWI discovers a crack running along the centerline of a weld bead. This defect is most likely caused by:

Accepted Answer

High sulfur or phosphorus content in the base metal

Answer

Centerline (hot) cracking is commonly caused by low-melting-point impurities such as sulfur and phosphorus segregating at the weld centerline.

Question 4

According to AWS D1.1, what is the minimum preheat temperature for welding 1-inch thick ASTM A36 steel when the ambient temperature is above 32°F?

Accepted Answer

No preheat required

Answer

AWS D1.1 Table 4.5 requires no minimum preheat for A36 steel up to 1.5 inches thick when temperature is above 32°F.

Question 5

Which discontinuity is characterized by fusion that does not extend to the full cross-section of the joint as specified?

Accepted Answer

Incomplete joint penetration

Answer

Incomplete joint penetration occurs when the weld metal fails to extend through the full thickness specified in the design.

CWI Practice Test