Investigation into Competitive Mechanism of Carbon Partitioning and Pseudospinodal Decomposition of Supersaturated Martensite in Q&P Steel Containing High Silicon

The article delves into the intricate mechanisms of carbon partitioning and pseudospinodal decomposition in Q&P steel, particularly focusing on the competitive dynamics between these processes. By employing advanced characterization techniques such as differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and three-dimensional atom probe (3DAP), the researchers uncover the detailed microstructural transformations and phase interactions within the steel. The study reveals that carbon concentration fluctuations, driven by segregation at crystallographic imperfections, play a crucial role in stimulating pseudospinodal decomposition and the formation of superlattice-ordered structures. These findings challenge the conventional CCE model and provide novel insights into the complex interplay between carbon partitioning and pseudospinodal decomposition, highlighting the significance of silicon segregation and its impact on the growth kinetics of α′′-Fe16C2. The article underscores the need for more accurate models that incorporate these thermal activation reactions, offering a comprehensive understanding of the microstructural evolution in Q&P steel.