Secondary recrystallization or normal grain growth?

The grain growth process in the presence of pinning force was investigated by computer simulation. The pinning force was assumed to change its value from high to low, these changes being proceeded at different rates. The initial value of the pinning force was chosen in such a way that the changes of the average grain size were suppressed. It was shown that the mode of growth process during reduction of the pinning force is either normal grain growth or secondary recrystallization with the subsequent normal grain growth depending on both the rate of the pinning force reduction and the initial magnitude of the pinning force. An abrupt reduction of the pinning force leads to normal grain growth that can evolve more rapidly than in the presence of a low pinning force from the very beginning of the process. A gradual reduction of the pinning force provides the development of secondary recrystallization in case a noticeable grain size nonhomogeneity is evolved prior to the reduction of the pinning force.