Question

1 Which of the following is the hardest constituent of steel? Ledeburite Austenite Bainite Martensite

Answer 1

Explanation:

Martensite is the hardest constituent of steel. The primary reasons accounting for this could be, the internal strains within BCC iron due to the excess carbon presence and due to the plastic deformation of parent FCC iron (austenite) surrounding the martensitic plate.

Answer 2

Martensite is the hardest constituent of steel. Option d is the correct answer.

• The martensite created in maraging steel is not the same as the martensite found in ordinary carbon steel. Quenching is used to create martensite in ordinary carbon steel.
• This martensite has a BCT structure and is hard and brittle. In the case of maraging steel, however, martensite production happens even when the material is cooled by air.
• Because of the reduced carbon content and higher Ni concentration, this is the case. The resulting martensite is soft and has a BCC structure.