Quiz 4

Question 1

Which of the following solid phases in the iron–carbon system has a BCC crystal structure and forms at temperatures below 1000°C?

Answer 1

Alpha Ferrite

Question 2

What is true of the properties of cementite?

Answer 2

It is hard and brittle

Question 3

A plain-carbon steel that contains 0.77% C is called a-

Answer 3

Eutectoid steel

Question 4

What heat treatment prevents ductility and toughness of martensite from decreasing with an increase in carbon content?

Answer 4

Tempering below the eutectoid temperature of 727 C

Question 5

Sequence of steps in the isothermal transformation of a steel sample

Answer 5

1.The sample is austenitized by heating it above the eutectoid temperature.
2.The sample is rapidly cooled in a liquid salt bath to the desired temperature below the eutectoid temperature.
3.The sample is removed from a liquid salt bath after a specific time interval.
4.The sample is quenched in water at room temperature.
5. The microstructure of the sample is examined at room temperature.