Ramachandran, Dileep ChandranFigueredo, BrunaSherepenko, OleksiiJin, WoosungPark, Yeong-DoBiro, Elliot2025-01-072025-01-072022-01-17https://doi.org/10.1016/j.jmapro.2022.01.019https://hdl.handle.net/10012/21315The final publication is available at Elsevier via https://doi.org/10.1016/j.jmapro.2022.01.019. © 2022. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This study focuses on improving the mechanical performance of third-generation Q&P steel resistance spot welds using a double-pulse welding cycle. Single and double-pulse welding schedules were implemented to assess the mechanical performance of the welds. Single-pulse welds exhibited poor cross-tension strength (CTS) values, failed around the fusion zone, and were accompanied by poor energy absorption capability. However, the double-pulse schedule showed improved CTS values by 33%, with an associated 110% increase in absorbed energy. The failure path observed from interrupted cross-tension tests showed that, in welds made using both pulsing schedules, failure proceeded along the fusion boundary and CGHAZ. In the single-pulse welds failed in brittle fashion, whereas the welds made with a double-pulse schedule exhibited a mixed (ductile and brittle) fracture morphology. The high-density microhardness mapping confirmed the presence of a localized softened zone (halo ring) adjacent to the fusion boundary in single-pulse welds. Strong elemental partitioning of Mn, Si, and C in the vicinity of the fusion boundary during long welding time was the primary cause for the halo formation. However, the halo ring was eliminated by performing a double-pulse weld schedule with 30 ms cooling time in between pulses; resulting in improved mechanical properties.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/advanced high strength steelsquenched & partitioned steelresistance spot weldingmicrostructuremechanical propertiesfailure behavioursArticle