Comparative Study of Microstructure, Texture Evolution and Mechanical Behavior of Additively Manufactured and Conventionally Processed Maraging 300 Steel

This study compares the microstructure, texture evolution, and mechanical behavior of Maraging 300 steel produced by selective laser melting (SLM) and conventional manufacturing (CM), subjected to solid solution treatment, cold rolling (up to 89.4% reduction), and aging. Results showed that while both routes achieved similar hardness, AM maintained stable hardness at extreme deformations, whereas CM peaked at 80.7% reduction. Tensile tests at ~80% reduction revealed that CM achieved higher ultimate tensile strength (2105 MPa) than AM (1807 MPa), but AM demonstrated superior ductility (16.7% vs. 10.8%). Electron Backscatter Diffraction (EBSD) analyses indicated that the AM material accommodated strain more homogeneously due to its initial fine cellular substructure, leading to greater crystallographic fragmentation, whereas CM exhibited pronounced strain localization. In conclusion, the initial microstructural state dictated by the manufacturing route fundamentally governs the deformation mechanisms, explaining the distinct strength–ductility balance observed between additively and conventionally processed Maraging 300 steel.