CWS CWS Metallurgy & Material Properties 2

Question 1

Which type of stainless steel is generally considered non-magnetic and cannot be hardened by heat treatment?

Accepted Answer

Austenitic stainless steel

Answer

Austenitic stainless steels (300 series) have a face-centered cubic (FCC) structure that makes them non-magnetic and not hardenable by heat treatment.

Question 2

What welding phenomenon is characterized by intergranular cracking in the HAZ of nickel-base alloys during welding?

Accepted Answer

Liquation cracking

Answer

Liquation cracking occurs in the partially-melted zone (PMZ) of the HAZ when low-melting-point constituents at grain boundaries liquefy during welding.

Question 3

A CWS supervisor is working with ASTM A36 and A514 steel in the same structure. What is the correct filler metal selection for a critical joint between these two steels?

Accepted Answer

Match the weaker A36 steel

Answer

When joining dissimilar strength steels, the filler metal should match the lower-strength base metal (A36) to maintain joint ductility and avoid cracking.

Question 4

What is 'lamellar tearing' and in what base metal orientation does it most commonly occur?

Accepted Answer

Subsurface cracking from through-thickness stress on plate with low short-transverse ductility; occurs in the Z-direction

Answer

Lamellar tearing is subsurface cracking caused by through-thickness (Z-direction) tensile stress in rolled plate with non-metallic inclusions aligned parallel to the surface.

Question 5

What does a high carbon equivalent (CE > 0.45) indicate about a steel's weldability?

Accepted Answer

Increased susceptibility to hydrogen-induced cold cracking, requiring preheat

Answer

A carbon equivalent above 0.45 indicates the steel will harden significantly in the HAZ, making it susceptible to hydrogen-induced cold cracking and requiring preheat.

CWS - Certified Welding Supervisor Practice Test

CWS - Certified Welding Supervisor Practice Test

CWS CWS Metallurgy & Material Properties 2