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Automotive body structure light-weighting for internal combustion engine vehicles is constrained by simultaneous and increasingly challenging vehicle cost, fuel economy and passenger safety standards. Mass optimization via materials selection in internal combustion engine vehicles, therefore, is ultimately dependent on the normalized cost of mass reduction solutions and the associated implications on passenger safety and vehicle performance metrics. These constraints have resulted in development and implementation of increasingly high specific-strength solutions for metallic components in the body structure and chassis. In contrast, mass optimization in battery electric vehicles is subject to alternative performance metrics to fuel efficiency, although considerations for vehicle safety and cost naturally remain directionally similar.

Performance evaluation of martensitic press-hardened steels by VDA 238-100 three-point bend testing has become commonplace. Significant influences on bending performance exist from both surface considerations related to both decarburization and substrate-coating interaction and base martensitic steel considerations such as structural heterogeneity, i.e., banding, prior austenite grain size, titanium nitride (TiN) dispersion, mobile hydrogen, and the extent of martensite tempering as result auto-tempering upon quenching or paint baking during vehicle manufacturing. Deconvolution of such effects is challenging in practice, but it is increasingly accepted that surface considerations play an outsized role in bending performance. For specified surface conditions, however, the base steel microstructure can greatly influence bending performance and associated crash ductility to meet safety and mass-efficiency targets.

Circular welded tailored blanks have an interesting potential for the manufacturing of weight optimised shock towers. However, it is not clear how the circular weld seam will behave when the component is exposed to fatigue and corrosion effects as they occur during driving. Therefore, appropriate tests have been performed to supply data on both issues. Model components deep drawn from blanks having circular welded reinforcement were submitted to variable amplitude loading in a servo-hydraulic fatigue frame. No fatigue damage was observed on the circular weld seam. The fatigue endurance correlates with the component stiffness which is in turn influenced by the diameter of the circular weld seam. Several components were coated by an industrial painting process and subjected to a tough cyclic corrosion test. All circular welded components showed an excellent corrosion resistance even on the weld seam.