Austempering is the heat treatment process used to obtain greater

Austempering is a specialized heat treatment process used primarily for steels and cast irons to enhance their mechanical properties.

The process involves heating the metal to the austenitizing temperature and then rapidly cooling it to a temperature above the martensite start (Ms) point, holding it there until the transformation to bainite occurs.

This bainitic structure provides an excellent combination of strength and toughness compared to conventional quenching and tempering methods.

Hardness (Option A) may increase slightly, but it is not the primary objective.

Brittleness (Option C) is actually reduced in austempered steel due to the absence of martensite.

Ductility (Option D) improves marginally, but the main goal is to achieve a strong yet tough microstructure.

Therefore, the primary purpose of austempering is to obtain greater strength in the steel, making Option B the correct answer.