CWI Weld Discontinuities and Defects 3

Question 1

A weld inspector observes that a weld bead has a very rough, irregular surface profile. Which process parameter is the MOST likely cause?

Accepted Answer

Incorrect polarity

Answer

Incorrect polarity in SMAW or GMAW can cause irregular, rough bead profiles as the arc characteristics become unstable and transfer changes.

Question 2

What is 'burn-through' in welding and when does it most commonly occur?

Accepted Answer

A hole melted completely through the base metal, common in thin sections

Answer

Burn-through is a hole melted completely through the base metal or weld, most commonly occurring when welding thin materials with excessive heat input.

Question 3

Which test method can directly measure the depth of undercut in a production weld?

Accepted Answer

Undercut gauge (fillet weld gauge)

Answer

An undercut gauge is a mechanical depth gauge used by welding inspectors to measure the actual depth of undercut at the weld toe.

Question 4

Stress corrosion cracking (SCC) in welds is promoted by which combination of conditions?

Accepted Answer

Tensile stress, susceptible material, and corrosive environment

Answer

SCC requires three simultaneous conditions: tensile residual or applied stress, a susceptible alloy microstructure, and a specific corrosive environment.

Question 5

In radiographic testing, a weld discontinuity that appears as an irregular dark area with no defined boundaries most likely indicates:

Accepted Answer

Slag inclusion

Answer

Slag inclusions typically appear as irregular dark areas with jagged or diffuse boundaries on radiographs, while porosity appears as rounded dark spots.

CWI Practice Test

CWI Practice Test

CWI Weld Discontinuities and Defects 3