Engineering Board Exam Reviewer · Engineering Materials · easy

The very hard, brittle microconstituent formed by rapidly quenching austenite is:

  1. Martensite
  2. Pearlite
  3. Ferrite
  4. Spheroidite

Answer

A. Martensite

Solution

It is a body-centered tetragonal (BCT) supersaturated solution of carbon in iron.

More Engineering Materials questions

  1. The lamellar mixture of ferrite and cementite formed by the eutectoid reaction in steel is called:
  2. The BCC phase of iron (α-iron) at room temperature is called:
  3. Iron carbide ( Fe3C) is also called:
  4. The eutectic composition in the iron–iron carbide system is approximately:
  5. The eutectoid temperature in the iron–iron carbide system is approximately:
  6. In the iron–carbon system, the eutectoid composition is about:
  7. A reaction in which one solid phase transforms into two other solid phases on cooling is called a/an:
  8. The rule used to determine the relative amounts of phases in a two-phase region of a binary phase diagram is the:
  9. A diagram that shows the phases present in an alloy system as a function of temperature and composition is called a:
  10. The temperature below which a BCC metal such as steel changes from ductile to brittle behavior is called the:

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