Influence of Annealing on Delamination Toughening of Mo-Bearing Medium-Carbon Steel with Ultrafine Elongated Grain Structure Processed by Warm Ternpforming

摘要

Ultrafine elongated grain (UFEG) structure with a strong // rolling direction fiber texture was created for a 0.4C-2Si-1Cr-1Mo steel (mass) through deformation of tempered martensite using multi-pass caliber rolling at 773 K with a rolling reduction of 78 (i.e. warm tempforming). Annealing of the warm tempformed steel at 843 K enhanced delamination toughening at lower temperatures without a significant loss of tensile strength at 1.8 GPa. It was suggested that delamination toughening was controlled through the precipitation of nanoscale Mo-rich precipitates in the UFEG structure.