Study of the annealing recrystallization process variables

The cold deformation of metals is known to mainly increase hardness and mechanical resistance with a corresponding decrease in ductility. When a degree of elevated reduction is achieved and the transformation process is still not finished, a thermal treatment must be carried out, annealing crystallization, in order to regenerate the structure and continue with the cold deformation process until achieving the expected size and section. Once the deformation is concluded a final thermal treatment must be performed to adjust the mechanical properties to the specification. For the final or intermediate thermal treatment to have the expected result, the parameters of temperature and time must be adjusted, depending on the initial grain size of the material to be deformed and the degree or percentage of deformation applied. The materials used in this study come from the cold deformation process using a cold pilgering laminator. Since this process yields big reductions in a single deformation stage the critical values of the thermal treatment parameters were studied in greater detail. This work aimed to determine the interrelationship of the cold deformation variables with the thermal treatment parameters and the resulting mechanical properties. Graphs of the development as a function of time and of the hardness for different annealing temperatures were obtained. For each one there was a minimum time at which the hardness obtained by cold deformation begins to drop sharply. These results are for practical application since they help to predict the thermal treatment conditions for obtaining the expected results