Re crystallization Annealing
It is the process of heating cold worked steel slightly above the re crystallization temperature to produce a new grain structure with out phase change. All steels that have been heavily cold worked are subjected to this process. There crystallization temperature is below the LCT. It result in decrease in hardness or strength and increase ductility. The process is frequently employed in industries manufacturing steel wires, sheets and strips. The temperature for this process is not fixed, since it depends on chemical composition, prior deformation, holding time and initial grain size. The larger the degree of deformation the lower is the recrystallization temperature. Recrystallization can be achieved even at lower temperatures, by increasing the holding time. But since the effect of temperature is predominant than that of holding time, it is always desirable to raise the recrystallization temperature instead of increasing holding time. High carbon steels and alloy steels require higher recrystallization temperature.
COMMENTS