AWS Welding Inspection, Testing & Quality Control 3 — Questions and Answers
Question 1: According to AWS D1.1, what is the minimum preheat temperature typically required when welding ASTM A36 steel with a thickness greater than 1.5 inches using a low-hydrogen process?
- 50°F (10°C)
- 150°F (66°C) (Correct answer)
- 225°F (107°C)
- 300°F (149°C)
Correct answer: 150°F (66°C)
AWS D1.1 requires a minimum preheat of 150°F (66°C) for Group I steels like A36 when thickness exceeds 1.5 inches with low-hydrogen electrodes.
Question 2: What is the primary purpose of a weld procedure qualification test (PQR)?
- To certify the welder's skill level
- To demonstrate that the welding process produces a joint with the required mechanical properties (Correct answer)
- To document electrode storage requirements
- To verify the inspector's credentials
Correct answer: To demonstrate that the welding process produces a joint with the required mechanical properties
The PQR is a record of actual test results used to prove that a welding procedure specification (WPS) will produce welds meeting specified mechanical requirements.
Question 3: In magnetic particle testing (MT), what type of discontinuity orientation produces the strongest indication?
- Parallel to the magnetic field
- Perpendicular to the magnetic field (Correct answer)
- At 45 degrees to the magnetic field
- Orientation has no effect on MT indications
Correct answer: Perpendicular to the magnetic field
Discontinuities oriented perpendicular to the magnetic field lines cause the greatest flux leakage, producing the strongest and most detectable MT indication.
Question 4: What does the letter 'E' designate in an electrode classification such as E7018?
- Electrode efficiency rating
- Arc energy level
- Electrode (filler metal rod) (Correct answer)
- Elongation percentage
Correct answer: Electrode (filler metal rod)
In the AWS electrode classification system, 'E' stands for electrode, indicating a coated filler metal rod used in SMAW.
Question 5: Which welding inspection method is classified as a volumetric examination technique?
- Visual testing (VT)
- Magnetic particle testing (MT)
- Liquid penetrant testing (PT)
- Radiographic testing (RT) (Correct answer)
Correct answer: Radiographic testing (RT)
Radiographic testing is a volumetric method that can detect discontinuities throughout the entire thickness of a weld, not just at the surface.
Question 6: What is the function of the heat-affected zone (HAZ) measurement in weld inspection?
- To measure the depth of incomplete fusion
- To assess the extent of metallurgical changes caused by welding heat in the base metal (Correct answer)
- To determine the weld bead width
- To calculate interpass temperature
Correct answer: To assess the extent of metallurgical changes caused by welding heat in the base metal
The HAZ is the base metal region adjacent to the weld that has experienced microstructural changes due to welding heat without melting, and its extent affects mechanical properties.
Question 7: When a guided bend test specimen fractures in the tension zone during testing, what does this typically indicate?
- The weld has acceptable ductility
- The weld contains a significant discontinuity such as lack of fusion or a crack (Correct answer)
- The base metal is too thin
- The bend radius was too large
Correct answer: The weld contains a significant discontinuity such as lack of fusion or a crack
Fracture during a guided bend test indicates the presence of a significant weld discontinuity such as cracking, lack of fusion, or excessive porosity that caused premature failure.
AWS Welding Inspection, Testing & Quality Control 3
According to AWS D1.1, what is the minimum preheat temperature typically required when welding ASTM A36 steel with a thickness greater than 1.5 inches using a low-hydrogen process?