A. Heating 750°C and slowly cooling to zero degree
B. Heating quickly upto 450°C followed by sudden quenching
C. Heating upto 250°C for 15 to 30 min
D. Heating at 750°C and then quenching to room temperature
Correct Answer: Heating upto 250°C for 15 to 30 min ✔
Last Updated: February 07, 2020