Martensitic transformations only occur in the Fe-C system. ___ Certain materials can age harden at room temperature. ___ Pure metals can be age hardened. ___ Tempering of martensitic steel increases its ductility. ___ Over-aging can occur when the aging temperature is large enough such that incoherent precipitates form.

a. False

b. True

c. False

d. True

e. True

Explanation:

The questions doesn't specify but it look most likely as a true/false question as most of its content are statement that are true/false

Martensitic transformation takes place first internally at the surface and it doesn't only occur in Fe-C system. It can occur in system like Cu-Al, Au-Cd, Fe-Ni etc

Certain materials can age harden at room temperature. Most material do harden at room temperature.

Pure metals cannot be age hardened. So, the statement from the question is False.

Tempering of martensitic steel increases its ductility; tempering of martensitic steel allows it to regain ductility.

Over-aging can occur when the aging temperature is large enough such that incoherent precipitates form.