AWS Welding Inspection, Testing & Quality Control 2 — Questions and Answers
Question 1: What does the term 'undercut' refer to in weld inspection?
- Excess weld metal above the base metal surface
- A groove melted into the base metal adjacent to the weld toe (Correct answer)
- An incomplete fusion between passes
- A crack running along the weld centerline
Correct answer: A groove melted into the base metal adjacent to the weld toe
Undercut is a groove or channel melted into the base metal at the weld toe that remains unfilled by weld metal.
Question 2: Which destructive test is specifically used to measure a weld's resistance to sudden impact loading?
- Tensile test
- Bend test
- Charpy V-notch test (Correct answer)
- Hardness test
Correct answer: Charpy V-notch test
The Charpy V-notch test measures the energy absorbed by a notched specimen when struck by a swinging pendulum, indicating toughness.
Question 3: In radiographic testing (RT), what appears darker on the film when compared to sound base metal?
- Porosity and voids (Correct answer)
- Dense inclusions
- Areas of increased thickness
- Properly fused weld metal
Correct answer: Porosity and voids
Voids and porosity allow more radiation to pass through, causing those areas to appear darker on radiographic film.
Question 4: What is the purpose of a macro-etch test on a weld cross-section?
- To detect surface cracks only
- To reveal the weld's internal structure, fusion zone, and HAZ (Correct answer)
- To measure tensile strength
- To check dimensional tolerances
Correct answer: To reveal the weld's internal structure, fusion zone, and HAZ
A macro-etch test uses acid to reveal the weld's cross-sectional structure, including the fusion zone, heat-affected zone, and any gross discontinuities.
Question 5: Which type of weld discontinuity is best detected by ultrasonic testing but may be missed by radiography?
- Porosity
- Slag inclusions
- Planar defects such as cracks and lack of fusion (Correct answer)
- Tungsten inclusions
Correct answer: Planar defects such as cracks and lack of fusion
Ultrasonic testing is highly sensitive to planar defects like cracks and lack of fusion because they reflect sound waves effectively, while radiography may miss them if oriented parallel to the beam.
Question 6: When performing a liquid penetrant test, what is the correct sequence of steps?
- Apply developer → apply penetrant → remove excess → inspect
- Clean surface → apply penetrant → dwell → remove excess → apply developer → inspect (Correct answer)
- Apply penetrant → clean → apply developer → inspect
- Clean → apply developer → apply penetrant → inspect
Correct answer: Clean surface → apply penetrant → dwell → remove excess → apply developer → inspect
The correct PT sequence is: clean the surface, apply penetrant, allow dwell time, remove excess penetrant, apply developer, then inspect.
Question 7: What does a 'nick-break' test primarily evaluate in a weld?
- Ductility of the base metal
- Internal soundness and fusion of the weld (Correct answer)
- Hardness of the heat-affected zone
- Tensile strength of the joint
Correct answer: Internal soundness and fusion of the weld
The nick-break test fractures a weld specimen to expose the interior, allowing visual evaluation of internal soundness, fusion, and the presence of porosity or slag.
AWS Welding Inspection, Testing & Quality Control 2
What does the term 'undercut' refer to in weld inspection?