AWS AWS Metallurgy & Materials

Question 1

Which iron-carbon phase forms when austenite is rapidly quenched and is known for its high hardness?

Accepted Answer

Martensite

Answer

Ferrite

Answer

Pearlite

Answer

Bainite

Question 2

What is the carbon content range (by weight) that defines low-carbon (mild) steel?

Accepted Answer

0.15%–0.30%

Answer

0.05%–0.15%

Answer

0.30%–0.60%

Answer

0.60%–1.00%

Question 3

The heat-affected zone (HAZ) in a weldment is the region that:

Accepted Answer

Was heated but did not melt, yet had its microstructure altered

Answer

Has been melted and resolidified

Answer

Remains completely unaffected by welding heat

Answer

Contains the weld metal deposit only

Question 4

Which alloying element in steel primarily improves hardenability by slowing the austenite-to-pearlite transformation?

Accepted Answer

Chromium

Answer

Sulfur

Answer

Phosphorus

Answer

Nitrogen

Question 5

What does the term 'weldability' primarily describe?

Accepted Answer

The ease with which a metal can be welded to produce a sound joint

Answer

The ability of a metal to be cut by plasma

Answer

The tensile strength of a completed weld

Answer

The melting point of a base metal

Question 6

Preheating before welding high-carbon steel primarily serves to:

Accepted Answer

Reduce the risk of hydrogen-induced cracking

Answer

Increase travel speed

Answer

Eliminate post-weld heat treatment

Answer

Increase weld bead convexity