Anomalous Dissolution Mechanism During Electropulsing-Assisted Solution Treatment Enhancing the Strength-Ductility Compatibility in Aermet 100 Steel

Abstract

A novel strategy aimed at controlling the abnormal dissolution mechanism of carbides during electropulsing is introduced, presenting a solution to the longstanding challenge of simultaneously enhancing steel strength and plasticity. Utilizing the electropulsing assisted solution (EAS) treatment, we prepared ultra-high strength steel with increased strength and plasticity at lower temperatures and in drastically reduced timeframes. The multiple strengthening mechanisms and the plasticizing mechanisms associated with multiscale microstructures are systematically discussed. Comparisons indicate that the strength and plasticity of steels treated with EAS surpass those of steels subjected to optimize conventional furnace solution treatment. Specifically, the experimental steel subjected to electropulsing assisted solution at 850 °C for 45 min showcased a maximum tensile strength of 1924.5 MPa. This impressive feat is credited to a high dislocation strengthening of 582.3 MPa and a grain refinement strengthening of 159.7 MPa. Additionally, a peak elongation-to-failure of approximately 14.2% was observed in EAS at 885 °C for 30 min. This improvement can be attributed to the activation of the slip system, coupled with an increase in the high-angle grain boundaries fraction numbers. These changes, in turn, amplify the coordinated deformation capacity, minimizing crack propagation.

Graphical Abstract