Thermomechanical simulation of the heat-affected zones in welded ultra-high strength steels: Microstructure and mechanical properties

Ultra-high strength steels (UHSS) have a determining role in construction and industry. Furthermore, welding as the primary joining process for steel has similar promoting its applications. Therefore, welded UHSS vital related However, due to their complex microstructures, these are more prone harmful effects of heat input on mechanical properties compared mild steels. Thus, identifying correlations between microstructural transformations triggered by can lead new insights hindering drawbacks. This study investigates microstructures S960 (with severe softening after welding) S1100 negligible decrease understand mechanisms behind UHSS. Microstructural analysis showed formation soft phases, e.g., ferrite granular bainite, reason softening. tempered forms martensite bainite resulted simultaneous hardness notch toughness. Finally, applicabilities two experimental approaches predict from constituents were evaluated proved relatively good reliability detect HAZ softened spots.