Mechanical Engineering - Engineering Materials - Discussion

Tempering is a process in which hardened steel (Martensite) is transformed into soft steel with increase in toughness.

Well explained, Thanks everyone.

Annealing is the right answer.

The correct answer is: Annealing.

Annealing is a heat treatment process used to soften hardened steel by:

1. Heating the steel to a specific temperature (usually between 800°C to 900°C) to relieve internal stresses and reduce hardness.
2. Holding the temperature for some time to allow the steel to fully transform into a softer microstructure.
3. Cooling the steel slowly to prevent re-hardening.

Annealing is often used to:

- Soften hardened steel for machining or forming.
- Relieve internal stresses and prevent cracking.
- Improve ductility and toughness.

The other options are not used for softening hardened steel:

- Carburising: A surface hardening process that adds carbon to the steel surface.
- Normalising: A heat treatment process that refines the microstructure and relieves internal stresses, but does not significantly soften the steel.
- Tempering: A heat treatment process that reduces the hardness of quenched steel, but is not used to soften fully hardened steel.

=> Note that the specific heat treatment process and parameters may vary depending on the steel grade and application.