AWS AWS Metallurgy & Materials 1

Question 1

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

Accepted Answer

Martensite

Answer

Martensite forms during rapid quenching of austenite and is the hardest iron-carbon microstructure.

Question 2

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

Accepted Answer

0.15%–0.30%

Answer

Low-carbon or mild steel contains approximately 0.15%–0.30% carbon by weight.

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

The HAZ is the base metal region adjacent to the weld that was heated enough to alter its microstructure without melting.

Question 4

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

Accepted Answer

Chromium

Answer

Chromium is a strong carbide former that significantly improves hardenability in steel.

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

Weldability refers to how readily a material can be welded to form a defect-free, serviceable joint.

AWS Practice Test