Research on Internal Crack Formation and Segregation Distribution in the Solidification Reduction Process

To investigate the influence of soft reduction technology on internal cracks and segregation during billet solidification, laboratory solidification reduction experiments are carried out on a steel ingot with a diameter of 44 mm and a height of 46 mm. Corresponding numerical simulations are conducted, and electron microscope detection is combined. The influences of mechanical stress, equivalent stress, strain, reduction parameters on the formation of internal cracks, and the distribution of segregation are analyzed. The research reveals that excessive reduction during the solidification reduction process will cause severe plastic deformation inside the billet, which in turn generates excessive equivalent stress and strain. This results in cracks forming along the central shrinkage and porosity regions, where plasticity and toughness are poor, and extending toward the surface under the action of stress and strain. Soft reduction can effectively reduce central segregation, improving the plasticity and toughness of the billet, thus preventing the formation of internal cracks. Additionally, by collecting the reduction external force during the solidification reduction process, the mechanical stress of the solidification reduction process is digitized, which improves the safety of reduction equipment and operators and provides new solutions for soft reduction technology in addressing defects such as segregation and cracks.