Abstract: | Conclusions The high dislocation density of austenite undergoing the ![gamma](/content/xu1618g254428620/xxlarge947.gif) ![rarr](/content/xu1618g254428620/xxlarge8594.gif) ![agr](/content/xu1618g254428620/xxlarge945.gif) ![rarr](/content/xu1618g254428620/xxlarge8594.gif) transformation is due to the influence of fresh dislocations that occur during the ![agr](/content/xu1618g254428620/xxlarge945.gif) ![rarr](/content/xu1618g254428620/xxlarge8594.gif) transformation in virtue of its martensitic character and to dislocations inherited from the original phases.Since the increase of the dislocation density in austenite causes an increase in the number of martensite crystals, it can be assumed that the increase in the number of phase nuclei is due to an increase in the density of fresh dislocations. In this case the refining of martensite is due to an increase in the number of nuclei and to the barrier effect of elements of the substructure. The formation of atmospheres of impurity atoms at dislocations in alloys with carbon stabilizes the austenite and intensifies recrystallization processes. Cementite particles in phase are not inherited by austenite with heating to the ![agr](/content/xu1618g254428620/xxlarge945.gif) ![rarr](/content/xu1618g254428620/xxlarge8594.gif) transformation temperature.Institute of Metal Physics, Academy of Sciences Ukrainian SSR. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 20–23, January, 1975. |