The Local Texture Analysis of Structural Inhomogeneities in Low-Carbon High-Strength Steel after Direct Quenching

摘要

Accelerated cooling of high-strength steels directly after hot rolling is economically efficient because it makes it possible to exclude their quenching following furnace heating. However, after such a treatment, the material possesses structural features that require special analysis. In particular, extended domains of a coarse bainite structure which induce a decrease in the fracture toughness of steel can sometimes be observed after direct quenching (DQ). To reveal the dependence of such effects on the characteristic features of austenite deformation, the local textures that make it possible to reconstruct the textures of the parent gamma phase taking into account the interphase orientation relationships are analyzed by EBSD. According to the obtained results, unfavorable structural inhomogeneities appear after DQ owing to the excessive work hardening of austenite at the final stage of rolling, but can be eliminated by quenching following furnace heating.