Heat treatment for softening hardened steel Which heat treatment process is primarily used to soften hardened steel and refine its structure for machining/formability? Choose the correct option.

ConceptAnnealing involves heating to a suitable temperature, holding, and cooling slowly (usually in the furnace) to soften the steel, increase ductility, and relieve stresses. Tempering reduces brittleness of quenched steel but does not fully soften it; carburising adds carbon; normalising air-cools and yields higher hardness than full anneal.

Final AnswerAnnealing