Certified Welder Weld Inspection and Defects 2 — Questions and Answers
Question 1: Which destructive test is used to evaluate the ductility and soundness of a weld by bending the specimen around a mandrel?
- Charpy impact test
- Guided bend test (Correct answer)
- Hardness test
- Tensile test
Correct answer: Guided bend test
The guided bend test bends a weld specimen around a mandrel of specified diameter to reveal surface cracks, lack of fusion, and porosity.
Question 2: Lamellar tearing in a weld joint is most commonly caused by:
- Excessive heat input
- High sulfur content in base metal and through-thickness loading (Correct answer)
- Hydrogen embrittlement in the weld metal
- Improper shielding gas mixture
Correct answer: High sulfur content in base metal and through-thickness loading
Lamellar tearing occurs in base metal with low through-thickness ductility (often due to sulfide inclusions) when restrained welds apply stress in the Z-direction.
Question 3: What does the term 'lack of sidewall fusion' specifically describe?
- Incomplete fusion between the root pass and the base metal
- Incomplete fusion between the weld metal and the groove face of the base metal (Correct answer)
- A gap at the root of the joint left unfilled
- Porosity located along the weld centerline
Correct answer: Incomplete fusion between the weld metal and the groove face of the base metal
Lack of sidewall fusion means the weld metal did not bond properly to the vertical groove faces of the base material on either side of the joint.
Question 4: During radiographic testing, a linear indication parallel to the weld axis most likely represents:
- Transverse crack
- Tungsten inclusion
- Longitudinal crack or lack of fusion (Correct answer)
- Isolated pore
Correct answer: Longitudinal crack or lack of fusion
Linear indications aligned with the weld axis on a radiograph typically indicate longitudinal cracks or planar lack-of-fusion defects.
Question 5: Which weld discontinuity is most likely detected by magnetic particle testing but NOT by liquid penetrant testing?
- Surface porosity open to the outside
- Subsurface crack just below the surface (Correct answer)
- Surface hot crack
- Undercut at the weld toe
Correct answer: Subsurface crack just below the surface
Magnetic particle testing can detect near-surface subsurface discontinuities, while liquid penetrant testing is limited strictly to surface-open defects.
Question 6: A welder notices fisheye fractures on the face of a broken tensile specimen. This indicates the presence of:
- Sulfur segregation
- Hydrogen-induced porosity or inclusions (Correct answer)
- Excessive carbon content in filler metal
- Cold lap on the surface
Correct answer: Hydrogen-induced porosity or inclusions
Fisheyes are circular shiny spots on a fracture surface caused by hydrogen trapped in the weld metal around pores or inclusions.
Question 7: What standard acceptance criterion terminology indicates a discontinuity that does NOT meet code requirements and must be repaired or removed?
- Indication
- Relevant indication
- Rejectable defect (Correct answer)
- Non-relevant indication
Correct answer: Rejectable defect
A 'defect' is a discontinuity that exceeds the acceptance criteria of the applicable code, making it rejectable and requiring repair or removal.
Certified Welder Weld Inspection and Defects 2
Which destructive test is used to evaluate the ductility and soundness of a weld by bending the specimen around a mandrel?