AWS Welding Defects & Quality Control 5

Question 1

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:

Accepted Answer

Underfill

Answer

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.

Question 2

Which destructive test is used to evaluate the through-thickness ductility of base metal to detect susceptibility to lamellar tearing?

Accepted Answer

Z-direction tensile test

Answer

The Z-direction (through-thickness) tensile test measures ductility perpendicular to the plate surface, directly assessing a material's susceptibility to lamellar tearing.

Question 3

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:

Accepted Answer

Inadequate back-purging with inert gas

Answer

Inadequate back-purging allows atmospheric oxygen to contact the hot weld root, causing oxidation (sugaring) that degrades corrosion resistance and indicates poor quality.

Question 4

In phased array ultrasonic testing (PAUT), what is the primary advantage over conventional single-element UT for weld inspection?

Accepted Answer

Ability to electronically steer and focus the beam without moving the probe

Answer

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.

Question 5

What is the purpose of a weld procedure qualification test (PQR) in AWS quality control?

Accepted Answer

To demonstrate that a welding procedure produces welds meeting specified mechanical property requirements

Answer

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.

AWS Practice Test

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AWS Welding Defects & Quality Control 5