Phase Diagrams and Microstructure Quiz

What is the maximum solubility of carbon in alpha iron (α-Fe) at 910 °C?

• 0.022 wt%

• 0.5 wt%

• 2.14 wt%

• 0.021 wt%

At what temperature does gamma iron (γ-Fe) transform to delta iron (δ-Fe)?

• 727 °C

• 1,538 °C

• 1,394 °C

• 912 °C

Which phase diagram is an example of an isomorphous system?

• Copper-zinc (Cu-Zn)

• Iron-carbon (Fe-C)

• Copper-nickel (Cu-Ni)

• Iron-iron carbide (Fe-Fe3C)

What is the crystal structure of gamma iron (γ-Fe)?

• Hexagonal close-packed (HCP)

• Simple cubic (SC)

• Body-centered cubic (BCC)

• Face-centered cubic (FCC)

What is the primary characteristic of cementite (Fe3C)?

• It is very ductile

• It is very hard and brittle

• It is non-magnetic

• It has a low melting point