Welding Inspection, Testing & Quality Control Flashcards

What does 'interpass temperature' refer to in a multi-pass weld?

Answer: The maximum temperature of the weld and adjacent base metal before depositing the next pass

Interpass temperature is the temperature of the weld joint immediately before depositing a subsequent weld pass, and controlling it prevents overheating or excessive cooling.

Which weld discontinuity is most commonly associated with improper shielding gas coverage during GMAW?

Answer: Porosity

Inadequate or contaminated shielding gas allows atmospheric oxygen and nitrogen to enter the weld pool, causing porosity in GMAW welds.

What is the significance of the 'essential variable' concept in welding procedure qualification?

Answer: A change to an essential variable requires requalification of the welding procedure

Essential variables are those parameters that, if changed beyond specified limits, significantly affect the mechanical properties or soundness of the weld, requiring procedure requalification.

Which destructive test method is used to evaluate the hardness distribution across a weld cross-section, including the HAZ?

Answer: Vickers or Rockwell hardness traverse

A hardness traverse using Vickers or Rockwell indentation tests is performed across a weld cross-section to map hardness variations in the weld metal, fusion zone, HAZ, and base metal.

In radiographic testing, what is the purpose of a penetrameter (IQI – Image Quality Indicator)?

Answer: To verify that the radiograph has sufficient sensitivity to detect relevant discontinuities

An IQI (penetrameter) is placed on the object during radiography to verify the technique achieves the required image sensitivity; if the IQI image is visible, the technique can detect similarly sized features.

What does the term 'lamellar tearing' describe in weld quality assessment?

Answer: Subsurface cracking in the base metal caused by through-thickness stress on material with low short-transverse ductility

Lamellar tearing is a step-like subsurface failure in the base metal beneath a weld, caused by high through-thickness tensile stress acting on non-metallic inclusions layered parallel to the plate surface.

What is the primary criterion used to accept or reject a weld based on visual inspection per AWS D1.1?

Answer: Comparison of measured weld dimensions and surface conditions against code-specified acceptance criteria

Visual inspection acceptance is based on comparing observable weld characteristics such as size, profile, cracks, and porosity against the specific acceptance criteria defined in AWS D1.1.