Ductility improvement of the 12Kh18N10T steel ingots when broaching

Dislocation and grain structure resulting from piercing of 12Kh18N10T steel blanks at different rates and temperatures affects the technological plasticity of the blanks, which grows with piercing temperature, the feed angle, the time of exposure to heating and the number of rollers revolutions. Central destruction involved in piercing is also essentially affected by the grain structure and by dislocation structure. Recrystallization structure in the central zone facilitates intergranular crack propagation. The optimum structure to hamper central fracturing is the sub-grain (polygonized) one, which shifts the recrystallization threshold towards higher temperatures and strains