Tempering

Several of the lost ductility because of quenching is restored through tempering. In such process the quenched metal is heated to some already decided temperature and metal is soaked for several times. The range of temperature utilized for steel is generally from 200°C to 600°C and cooling is completed in the furnace. The tempering treatment also assists remove internal stresses, which are created because of hardening treatment. UTS, Ys and hardness reduce when % elongation, impact strength increase because of tempering at temperatures of 300°C and over. There is little effect on these properties under 300°C.