Certified Welder Weld Inspection and Testing 3 — Questions and Answers
Question 1: What type of weld defect is identified by a groove melted into the base metal at the edge of a weld bead?
- Porosity
- Incomplete penetration
- Undercut (Correct answer)
- Burn-through
Correct answer: Undercut
Undercut is a groove or channel melted into the base metal along the weld toe, reducing the effective cross-section.
Question 2: A Charpy V-notch test primarily evaluates which mechanical property of a weld?
- Tensile strength
- Hardness
- Toughness (impact resistance) (Correct answer)
- Ductility
Correct answer: Toughness (impact resistance)
The Charpy V-notch test measures the energy absorbed by a notched specimen when struck by a pendulum, indicating toughness.
Question 3: In magnetic particle testing (MT), what is the correct sequence for wet fluorescent MT?
- Apply particles, magnetize, view under UV light
- Magnetize, apply particles, view under UV light (Correct answer)
- View under UV light, magnetize, apply particles
- Apply particles, view under UV light, magnetize
Correct answer: Magnetize, apply particles, view under UV light
The correct MT sequence is magnetize the part first, then apply the magnetic particle medium, then view under UV (black) light.
Question 4: Which weld discontinuity is most likely caused by welding over a contaminated or painted surface?
- Undercut
- Porosity (Correct answer)
- Longitudinal cracking
- Burn-through
Correct answer: Porosity
Porosity is commonly caused by gas trapped in the weld pool from contaminants such as oil, paint, moisture, or rust on the base metal.
Question 5: When performing a guided bend test, the face bend tests for:
- Root fusion and penetration
- Surface and near-surface defects on the weld face (Correct answer)
- Base metal strength
- Heat-affected zone toughness
Correct answer: Surface and near-surface defects on the weld face
A face bend test bends the specimen with the weld face in tension, revealing surface and near-surface defects on the crown side.
Question 6: What is 'incomplete fusion' in a weld?
- Weld metal that solidified too quickly
- A lack of bonding between weld metal and base metal or between weld passes (Correct answer)
- Excessive weld reinforcement
- A weld made with too low a current
Correct answer: A lack of bonding between weld metal and base metal or between weld passes
Incomplete fusion (lack of fusion) occurs when the weld metal fails to fuse completely with the base metal or adjacent weld passes.
Question 7: Which inspection method requires the test surface to be non-porous and uses a developer to draw out indications?
- Magnetic particle testing
- Liquid penetrant testing (Correct answer)
- Radiographic testing
- Ultrasonic testing
Correct answer: Liquid penetrant testing
Liquid penetrant testing (PT) uses capillary action to draw penetrant into surface-breaking defects, then a developer draws it back out as visible indications.
Certified Welder Weld Inspection and Testing 3
What type of weld defect is identified by a groove melted into the base metal at the edge of a weld bead?