AWS Inspection & Quality Control 3 — Questions and Answers
Question 1: According to AWS standards, what is the minimum preheat temperature purpose in welding inspection?
- To increase welding speed
- To reduce hardness in the HAZ and minimize hydrogen cracking (Correct answer)
- To eliminate the need for post-weld heat treatment
- To prevent distortion during cooling
Correct answer: To reduce hardness in the HAZ and minimize hydrogen cracking
Preheat reduces the cooling rate in the HAZ, lowers hardness, and allows hydrogen to escape, thereby minimizing the risk of hydrogen-induced cracking.
Question 2: Which nondestructive examination method uses sound waves above 20 kHz to detect internal discontinuities?
- Magnetic particle testing
- Liquid penetrant testing
- Ultrasonic testing (Correct answer)
- Eddy current testing
Correct answer: Ultrasonic testing
Ultrasonic testing (UT) uses high-frequency sound waves transmitted through the material to detect and characterize internal flaws.
Question 3: During a welder qualification test, what is the purpose of the root bend specimen?
- To test the tensile strength of the weld
- To evaluate soundness of the weld root (Correct answer)
- To measure weld hardness
- To check the weld bead profile
Correct answer: To evaluate soundness of the weld root
The root bend test bends the specimen with the weld root in tension to reveal lack of fusion, cracks, or other defects at the weld root.
Question 4: What term describes the groove melted into the base metal adjacent to the weld toe, which reduces the cross-section of the base metal?
- Concavity
- Overlap
- Undercut (Correct answer)
- Burn-through
Correct answer: Undercut
Undercut is a groove melted into the base metal at the weld toe that is not filled with weld metal, reducing the effective cross-sectional area.
Question 5: In magnetic particle testing (MT), which type of magnetization is best for detecting longitudinal cracks parallel to the weld axis?
- Circular magnetization (Correct answer)
- Longitudinal magnetization
- Alternating current yoke only
- Prod technique
Correct answer: Circular magnetization
Circular magnetization creates magnetic field lines perpendicular to the weld axis, making it optimal for detecting longitudinal (parallel) cracks.
Question 6: What is the purpose of post-weld heat treatment (PWHT) from an inspection standpoint?
- To increase weld metal hardness
- To reduce residual stresses and improve toughness (Correct answer)
- To add carbon to the weld zone
- To eliminate all weld discontinuities
Correct answer: To reduce residual stresses and improve toughness
PWHT relieves residual stresses induced during welding and can improve toughness, ductility, and corrosion resistance of the weld and HAZ.
Question 7: Which AWS document establishes the structural welding code for steel and contains acceptance criteria for weld quality?
- AWS D1.1 (Correct answer)
- AWS A5.1
- AWS B2.1
- AWS D1.5
Correct answer: AWS D1.1
AWS D1.1 Structural Welding Code—Steel contains provisions for design, procedures, qualifications, fabrication, inspection, and repair of welded steel structures.
AWS Inspection & Quality Control 3
According to AWS standards, what is the minimum preheat temperature purpose in welding inspection?