The results of the metallographic study of the structural state of the metal continuously cast billets after “soft” reduction is presented. Deformation of the billet was made in the CCM line in the withdrawal unit in the presence of a non-crystallized axial area in it, reduction was carried out by moving the upper drive roll. As a result of the metallographic studies revealed features of the mechanism of crack formation in the application of external deformation effects at the stage of incomplete crystallization of the billet, which will allow a more reasonable approach to the selection of technological methods that minimize the number of centers of their origin.