CWI Fundamentals 5 — Questions and Answers
Question 1: What is the meaning of the flag symbol on a weld symbol's reference line?
- The weld must be made by a certified welder only
- The weld is to be made in the field (not in the shop) (Correct answer)
- The weld requires postweld heat treatment
- The weld is a complete joint penetration weld
Correct answer: The weld is to be made in the field (not in the shop)
A flag (pennant) at the junction of the reference line and arrow indicates a field weld, meaning it is to be performed at the erection site rather than in the fabrication shop.
Question 2: Which condition describes 'overlap' as a weld discontinuity?
- Weld metal that has not fused with the base metal but has rolled over the weld toe (Correct answer)
- A groove eroded into the base metal at the edge of the weld
- Incomplete filling of the weld groove
- Solidification cracking along the longitudinal axis of the weld
Correct answer: Weld metal that has not fused with the base metal but has rolled over the weld toe
Overlap occurs when weld metal flows beyond the weld toe onto the base metal surface without fusing, creating a notch-like condition at the interface.
Question 3: A CWI must verify that a filler metal bears an AWS classification label before use. This requirement primarily ensures:
- The filler metal will not produce any spatter during welding
- The filler metal meets minimum mechanical and chemical composition requirements (Correct answer)
- The electrode has been dried in an oven for at least 2 hours
- The electrode diameter matches the base metal thickness exactly
Correct answer: The filler metal meets minimum mechanical and chemical composition requirements
AWS classification testing confirms that the filler metal's deposited weld metal meets specified tensile strength, yield strength, and chemical composition requirements.
Question 4: What is the typical angle of a 'V-groove' weld joint's included angle as commonly specified?
- 15° to 20°
- 30° to 45°
- 60° to 75° (Correct answer)
- 90° to 120°
Correct answer: 60° to 75°
A standard V-groove weld typically uses an included angle of 60° (30° bevel per side), though angles from 60° to 75° are common depending on the applicable code.
Question 5: Postweld heat treatment (PWHT) is primarily performed to:
- Increase the hardness of the weld deposit
- Relieve residual stresses in the weldment (Correct answer)
- Remove all hydrogen from the weld metal after cooling
- Increase the carbon content of the HAZ
Correct answer: Relieve residual stresses in the weldment
PWHT (stress relief) heats the weldment to a specified temperature below the transformation range to reduce residual welding stresses and temper hard HAZ microstructures.
Question 6: Which of the following is considered a surface discontinuity that can be detected by liquid penetrant testing (PT)?
- Porosity fully enclosed within the weld metal
- Slag inclusion buried in the weld
- A surface-connected crack at the weld toe (Correct answer)
- Incomplete joint penetration at the weld root (no back-side access)
Correct answer: A surface-connected crack at the weld toe
PT detects only surface-open discontinuities; a crack open to the surface at the weld toe will draw in penetrant and become visible during development.
Question 7: A welder qualification test is designed to determine:
- Whether the welding process can produce welds with acceptable mechanical properties
- Whether a specific welder has the skill to produce sound welds within qualified limits (Correct answer)
- The chemical composition requirements for filler metals used in production
- Whether the base metal meets minimum impact toughness requirements
Correct answer: Whether a specific welder has the skill to produce sound welds within qualified limits
Welder performance qualification (WPQ) tests the individual welder's ability and skill, distinguishing it from procedure qualification which tests the process parameters.
CWI Fundamentals 5
What is the meaning of the flag symbol on a weld symbol's reference line?