Quenching is not necessary when hardening is done by

A. Case hardening

B. Flame hardening

C. Nitriding

D. Any one of these

Answer: Option C

Solution(By Examveda Team)

Nitriding has a different hardening mechanism than the one caused by quenching a steel with an elevated level of carbon.
Instead, the hardening is caused by the fine scale precipitation of alloying element nitrides which does not require quenching.