AWS Weld Inspection & Quality Control 3 — Questions and Answers
Question 1: What is the purpose of a preheat treatment applied before welding high-carbon or alloy steels?
- To increase hardness of the weld zone
- To reduce the cooling rate and minimize hydrogen cracking (Correct answer)
- To eliminate the need for post-weld heat treatment
- To improve the appearance of the finished weld
Correct answer: To reduce the cooling rate and minimize hydrogen cracking
Preheat slows the cooling rate of the weld and heat-affected zone, reducing the risk of hydrogen-induced cracking and martensite formation.
Question 2: In radiographic testing, what does a lower image quality indicator (IQI) designation number indicate?
- Thicker wire or hole diameter, indicating lower sensitivity
- Thinner wire or smaller hole, indicating higher sensitivity (Correct answer)
- The IQI is out of calibration
- The radiograph was taken at a shorter source-to-film distance
Correct answer: Thinner wire or smaller hole, indicating higher sensitivity
A lower IQI wire or hole number indicates a smaller size; being able to see a smaller IQI means the technique has higher sensitivity.
Question 3: Which type of crack typically occurs in the heat-affected zone (HAZ) of high-strength low-alloy (HSLA) steels and is often caused by hydrogen?
- Hot crack
- Cold crack (hydrogen-induced cracking) (Correct answer)
- Solidification crack
- Reheat crack
Correct answer: Cold crack (hydrogen-induced cracking)
Cold cracking (hydrogen-induced cracking) occurs in the HAZ of HSLA steels below approximately 300°F as hydrogen diffuses to stress concentrations.
Question 4: A CWI reviewing a weld procedure specification (WPS) notices the preheat temperature listed is lower than that required by the applicable code. What should the inspector do?
- Accept the WPS since preheat is a recommendation, not a requirement
- Reject the WPS and require revision to meet code minimums (Correct answer)
- Allow the welder to compensate by slowing travel speed
- Stamp the WPS and add a note to the inspection record
Correct answer: Reject the WPS and require revision to meet code minimums
The WPS must conform to applicable code requirements; an insufficient preheat temperature is a nonconformance that requires the WPS to be revised.
Question 5: Which welding defect is caused by the entrapment of shielding gas or evolved gases during solidification of the weld pool?
- Slag inclusion
- Porosity (Correct answer)
- Undercut
- Overlap
Correct answer: Porosity
Porosity results from gas bubbles trapped in the solidifying weld metal, typically due to contamination, moisture, or loss of shielding gas coverage.
Question 6: When performing visual inspection of a completed weld, which tool is specifically used to measure the convexity or concavity of a weld bead profile?
- Depth micrometer
- Fillet weld gauge
- Bridge cam gauge (Correct answer)
- Vernier caliper
Correct answer: Bridge cam gauge
A bridge cam gauge (also called a Hi-Lo gauge or Tempilstik gauge) is used to measure weld profiles including convexity, concavity, and reinforcement height.
Question 7: In the context of AWS welding codes, what does the abbreviation 'PQR' stand for?
- Procedure Qualification Record (Correct answer)
- Pre-weld Quality Requirement
- Post-weld Quality Review
- Process and Quality Regulation
Correct answer: Procedure Qualification Record
PQR (Procedure Qualification Record) documents the actual welding parameters and test results used to qualify a welding procedure specification.
AWS Weld Inspection & Quality Control 3
What is the purpose of a preheat treatment applied before welding high-carbon or alloy steels?