AWS Weld Discontinuities & Defects 4

Question 1

Which discontinuity is most likely to occur when welding austenitic stainless steel with excessive heat input?

Accepted Answer

Hot cracking

Answer

Austenitic stainless steels are susceptible to hot cracking (solidification cracking) when high heat input causes low-melting impurity films to form along grain boundaries.

Question 2

A weld exhibiting 'wagon tracks' on a radiograph most likely contains which discontinuity?

Accepted Answer

Slag inclusions

Answer

Wagon tracks on a radiograph are parallel lines of slag inclusions typically found between weld passes in multi-pass welds.

Question 3

Which condition is the PRIMARY cause of lamellar tearing in structural weldments?

Accepted Answer

Low through-thickness ductility of the base metal

Answer

Lamellar tearing occurs when through-thickness shrinkage stresses exceed the low through-thickness ductility of base metal containing planar inclusions.

Question 4

A welder notices a groove melted into the base metal adjacent to the weld toe that is not filled by weld metal. This is called:

Accepted Answer

Undercut

Answer

Undercut is a groove melted into the base metal at the weld toe or weld root that is left unfilled by weld metal.

Question 5

Which nondestructive testing method is MOST effective for detecting subsurface porosity in a thick weld section?

Accepted Answer

Radiographic testing (RT)

Answer

Radiographic testing (RT) is most effective for detecting internal volumetric discontinuities like subsurface porosity in thick sections.

AWS Practice Test

AWS Practice Test

AWS Weld Discontinuities & Defects 4