ANS:B - bainite

Austempering of steel involves heating it to a specific temperature, followed by quenching it in a bath maintained at a certain temperature range. This process transforms the austenite phase into a desired microstructure. In austempering: The correct answer is: bainite During austempering, the steel is quenched into a bath maintained at a temperature typically between 250-525°C. This allows the formation of bainite, which is a microstructure consisting of fine carbide particles in a ferrite matrix. This microstructure provides a good combination of strength and toughness in the steel.