Mechanical Engineering - Engineering Materials - Discussion

Tempering: Tempering reduces the hardness in the martensite by transforming it into various forms of tempered martensite. Tempering is a heat treatment technique applied to ferrous alloys, such as steel or cast iron, to achieve greater toughness by decreasing the hardness of the alloy.

Annealing/Normalising: Annealing is a heat treatment process which alters the microstructure of a material to change its mechanical or electrical properties. Typically, in steels, annealing is used to reduce hardness, increase ductility and help eliminate internal stresses.

The correct answer is annealing.

Hardened steels here refer to martensitic steels, so tempering is the correct method of softening them i.e. improving the ductility by small amounts while reducing hardness and tensile strength by small amounts.

What is the correct answer? Please explain.