Optimizing LDX 2101 stainless steel: Microstructural insights and mechanical performance under varied rolling reduction

This study investigates the nuanced interplay between rolling reduction distribution, microstructure, and mechanical properties in LDX 2101 stainless steel. Engineering tensile stress-strain curves reveal distinct variations in yield strength (YS), ultimate tensile strength (UTS), and elongation across samples with different rolling reduction distributions. Microstructural analyses using SEM, EBSD, and TEM highlight the influence of Cr2N precipitates, low angle boundaries, and geometric necessary dislocations. Strengthening mechanisms, including grain size reduction, precipitation strengthening, and dislocation pinning are explored. The results indicated that the distribution of rolling reduction significantly impacts on strength and elongation. When the reduction of 50 % is distributed in the first pass (F50), the highest elongation (21 %) is obtained. When the reduction of 50 % is distributed in the middle pass (M50), the highest UTS (1035 MPa) is obtained. The main reason is Cr2N precipitated and dynamic recovery and recrystallization of ferrite. Besides, the transformation induced plasticity (TRIP) effect, involving austenite-to-martensite transformation during deformation, contributes to enhanced elongation. This comprehensive analysis provides valuable insights into optimizing the mechanical properties of stainless steel, offering implications for materials science and engineering applications.