A systematic study was conducted on the influence of silicon on the microstructure, stress distribution, and martensitic nucleation and transformation of 301 metastable austenitic stainless steel during cold-rolling deformation. When the deformation amount of conventional 301 stainless steel is ≤20%, the amount of martensite transformation is very small. When the deformation amount is ≥30%, the amount of martensite transformation significantly increases. The introduction of Si significantly improves the amount of martensite transformation and the uniformity of deformation. 301Si-H has a significantly higher amount of martensite in the same deformation microstructure than conventional 301Si-L with a lower silicon content. Increasing the Si content decreases the stacking fault energy of 301 stainless steel. During deformation, Si tends to cluster at the grain boundaries, reducing stacking fault width and increasing dislocation density, creating sites for shear martensite nucleation at the grain boundaries. Simultaneously, significant deformation encourages the formation of deformation twins and facilitates martensite nucleation.

This study systematically investigated the effects of selective laser melting (SLM) process parameters on the forming quality and microstructure of FeCrAl oxide dispersion-strengthened (ODS) alloy. Through orthogonal experimental design, the influences of laser power (300–320 W), scanning speed (650–850 mm/s), and hatch spacing (0.05–0.07 mm) on the surface morphology and internal defects of as-built samples were analyzed. The microstructural evolution under different volumetric energy densities (VED) was also analyzed. The results indicate that hatch spacing significantly affected crack and pore formation, with minimal defects observed at 0.06 mm. Excessive laser power (320 W) or VED (318.0 J/mm³) led to elevated melt pool temperatures, causing element evaporation, grain coarsening, and preferential oriented texture, thereby reducing hardness to 234 HV. The optimal parameters—laser power of 310 W, scanning speed of 650 mm/s, and hatch spacing of 0.06 mm (VED 265.0 J/mm³)—yielded the highest hardness (293 HV), fine-grained structures, and a high proportion of low-angle grain boundaries (LAGBs) with significant residual stress. This research provides a theoretical foundation for optimizing SLM processes for FeCrAl-ODS alloys.