Tempering is a heat treatment process primarily aimed at improving what property?

Tempering is a heat treatment process primarily aimed at improving what property?

• A. Hardness
• B. Ductility
• C. Toughness
• D. Corrosion resistance

Answer: (C)

Tempering aims to reduce brittleness and relieve residual stresses in hardened steel, thereby increasing toughness. After quenching, steel becomes very hard but can be extremely brittle due to a martensitic structure and internal stresses. Heating to a moderate temperature and holding allows carbon to redistribute and the lattice to relax, forming tempered martensite. This lowers brittleness and internal stress, so the material can absorb more energy before fracturing. Hardness is typically maintained at a useful level but may drop a bit, while ductility and impact resistance improve. Corrosion resistance isn’t the primary goal of tempering.

Tempering aims to reduce brittleness and relieve residual stresses in hardened steel, thereby increasing toughness. After quenching, steel becomes very hard but can be extremely brittle due to a martensitic structure and internal stresses. Heating to a moderate temperature and holding allows carbon to redistribute and the lattice to relax, forming tempered martensite. This lowers brittleness and internal stress, so the material can absorb more energy before fracturing. Hardness is typically maintained at a useful level but may drop a bit, while ductility and impact resistance improve. Corrosion resistance isn’t the primary goal of tempering.