NDT Weld Inspection & Evaluation 3

Question 1

During weld inspection, 'heat-affected zone (HAZ) cracking' most commonly occurs due to which condition?

Accepted Answer

High hydrogen content and rapid cooling of hardenable base metals

Answer

HAZ cracking (hydrogen-induced cracking) results from hydrogen absorbed during welding combined with rapid cooling of microstructures susceptible to hardening, creating brittle zones prone to cracking under residual stress.

Question 2

What is the theoretical throat of a flat-faced fillet weld with a 1/2-inch leg size?

Accepted Answer

0.354 inch

Answer

The theoretical throat equals 0.707 × leg size; for a 1/2-inch leg: 0.707 × 0.5 = 0.354 inch, representing the shortest distance from the weld root to the hypotenuse of the triangular cross-section.

Question 3

Which AWS code governs the structural welding of steel for pressure vessels and boiler applications inspected under NDT boilermaker standards?

Accepted Answer

ASME Section VIII Division 1

Answer

ASME Section VIII Division 1 is the primary code governing the design, fabrication, inspection, and certification of pressure vessels and boilers, making it the key standard for boilermaker NDT work.

Question 4

What type of weld discontinuity is described as a groove melted into the base metal adjacent to the weld toe?

Accepted Answer

Undercut

Answer

Undercut is a groove or channel burned into the base metal along the weld toe by excessive heat or current, reducing the effective cross-sectional thickness and creating a stress concentration.

Question 5

When visually inspecting a weld for surface porosity, an inspector finds pits on the weld face that break the surface. Under ASME Section VIII, this condition is:

Accepted Answer

Rejectable because surface porosity indicates potential internal porosity and incomplete fusion

Answer

Surface porosity in pressure vessel welds is rejectable under ASME Section VIII because open pits indicate gas entrapment that can extend internally, compromising the pressure boundary integrity.

(NDT) Boilermaker Nondestructive Testing Certification Practice Test

(NDT) Boilermaker Nondestructive Testing Certification Practice Test

NDT Weld Inspection & Evaluation 3