Multiscale thermo-metallo-mechanical-temporal coupling research on electron beam welding of AISI 410L/NS163 dissimilar systems

This review integrates a systematic research framework elucidating the evolution of electron beam welding joints of dissimilar AISI 410L ferritic stainless steel and NS163 Co-based superalloy from transient thermal transport to long-term aging-induced interfacial reconstruction. Thermal diffusivity, regulated by Co-induced lattice distortion and phonon-electron scattering, is identified as the primary parameter controlling molten pool morphology, heat-affected zone width, and cooling rate. Accelerated cooling further dictates solidification pathways, martensitic transformation modes, variant selection behavior, and residual stress distribution. During aging at elevated temperatures, precipitation-assisted diffusion blocking and thermodynamic lattice coherence optimization drive transition zone contraction and significant reduction of interfacial lattice mismatch, leading to enhanced mechanical compatibility and strength-ductility synergy. A unified thermo-metallo-mechanical-temporal coupling relationship is proposed to correlate thermal transport, phase transformation, residual stress evolution, and interfacial reconstruction with long-term reliability. This framework provides mechanistic insights and design strategies for optimizing EBW dissimilar systems in high-temperature brush seal applications.