Ramachandran, Dileep ChandranSalandari-Rabori, AdibMacwan, AndrewBiro, Elliot2025-01-072025-01-072024-09-09https://doi.org/10.1007/s11661-024-07573-8https://hdl.handle.net/10012/21321This is a post-peer-review, pre-copyedit version of an article published in [insert journal title]. The final authenticated version is available online at: https://doi.org/10.1007/s11661-024-07573-8The microstructure of the halo ring has been studied in quenched and partitioned (Q&P) steel resistance spot welds. The TEM and EBSD characterizations revealed the presence of an upper bainitic microstructure in the halo ring of the three-sheet stack-up welds. Stalking faults accompanied by nano-twins were identified surrounding the cementite. Diffusion of carbon towards the molten weld pool during solidification led to the formation of bainite at the fusion boundary, triggered the localized softening.enadvanced high strength steelsresistance spot weldinghalo ringmicrostructureTEMArticle