Recrystallization takes place by a combination of nucleation of strain free grains and the growth of these nuclei to absorb the entire cold worked material. The term recrystallization temperature does not refer to a definite temperature below which recrystallization will not occur, but refers to the approximate temperature at which a highly cold worked material completely recrystallizes in one hour. The recrystallization temperatures of several metals and alloys are listed in Table 1. Zinc 50 Tin 25 Lead 25 Table 1. Recrystallization temperatures for various metals and alloys.
Pure metals have low recrystallization temperatures as compared with alloys.
Zinc, tin and lead have recrystallization temperatures below room temperature. This means that these metals cannot be cold worked at room temperature since they crystallize spontaneously, reforming a strain free structure. The greater the prior deformation, the lower the temperature for the start of recrystallization. Increasing the annealing time decreases the recrystallization temperature for the start of recrystallization. Effect of annealing on tensile strength, hardness, ductility and grain size.