Welding Defects & Quality Control Flashcards
7 cards from real AWS practice questions. Tap to flip, then mark Knew It or Still Learning โ missed cards come back until you master them.
Read the first 7 Welding Defects & Quality Control flashcards as text
During visual inspection of a completed weld, the inspector finds the weld crown is 1/8 inch below the base metal surface. This defect is called:
Answer: Underfill
Underfill is a condition where the weld face is below the adjacent base metal surface, reducing the weld's cross-sectional area and load-carrying capacity.
Which destructive test is used to evaluate the through-thickness ductility of base metal to detect susceptibility to lamellar tearing?
Answer: Z-direction tensile test
The Z-direction (through-thickness) tensile test measures ductility perpendicular to the plate surface, directly assessing a material's susceptibility to lamellar tearing.
A weld made using GTAW on stainless steel exhibits a dark, sooty appearance on the back side of the weld. This is most likely caused by:
Answer: Inadequate back-purging with inert gas
Inadequate back-purging allows atmospheric oxygen to contact the hot weld root, causing oxidation (sugaring) that degrades corrosion resistance and indicates poor quality.
In phased array ultrasonic testing (PAUT), what is the primary advantage over conventional single-element UT for weld inspection?
Answer: Ability to electronically steer and focus the beam without moving the probe
PAUT uses multiple elements fired in programmed sequences to electronically steer and focus the ultrasonic beam, allowing more complete volumetric coverage of the weld without physically repositioning the transducer.
What is the purpose of a weld procedure qualification test (PQR) in AWS quality control?
Answer: To demonstrate that a welding procedure produces welds meeting specified mechanical property requirements
A Procedure Qualification Record (PQR) documents the results of testing a Welding Procedure Specification (WPS) to verify that the procedure produces welds with the required mechanical properties.
Hot cracking in austenitic stainless steel welds is best prevented by:
Answer: Maintaining a ferrite content of approximately 3-8 FN in the weld metal
A ferrite number (FN) of 3-8 in austenitic stainless steel weld metal interrupts the continuous austenite grain boundary network, preventing liquid films from forming and causing solidification (hot) cracking.
During RT film interpretation, a linear indication with parallel edges running along the weld axis most likely represents:
Answer: Incomplete fusion or incomplete joint penetration
Linear indications with parallel edges oriented along the weld axis are characteristic of incomplete fusion or incomplete joint penetration, which create planar discontinuities visible as elongated dark lines on radiographic film.