Project Details
Projekt
Developing crossover austenitic stainless steel based on scrap recycling via forward experimental and numerical high-throughput assessment of P-S-P linkages and inverse data-driven design
Subject Area
Mechanics
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 562096836
Steel production is responsible for about 25% of global industrial CO2 emissions. Hence, the transition from primary to secondary steel production via enhanced recycling rates (up to 100%) is key for reducing climate-damaging effects and for reaching global sustainability goals. However, in the case of stainless steel the high amount of alloying elements requires either use of high-quality, strictly sorted scrap (costly, challenging logistics) or the addition of suitable raw materials (limiting the scrap/fraction of recycled). A potential solution is crossover austenitic stainless steel (ASS), i.e. mixtures of various sorts of stainless steel, which enable fabrication based on 100% recycling material. However, the design of crossover ASS has not yet been proposed and the potential influence of tramp elements on their excellent mechanical properties (high strength, work-hardening capacity and ductility, along with excellent resilience under extreme operation environments) remains to be investigated fundamentally. Consequently, two aspects are addressed in the current proposal: (i) the resulting chemical composition(s) of crossover ASS will deviate strongly from currently standardized grades, and (ii) the amount of tramp elements (e.g., P, S, Cu) is inevitably enhanced. Profound investigation of these aspects, specifically the influence of varying chemical compositions on the resulting microstructure and mechanical behavior of ASS requires suitable methods for high-throughput sample production and subsequent quantitative assessment of the process-structure-properties (P-S-P) relationships by combined experimental and numerical approaches. Based on these P-S-P linkages, it is our overall objective to develop a data-driven inverse design strategy in order to discover novel mixtures of various sorts of stainless steel scrap, which enable fabrication based on 100% recycling material and thus, enhance the sustainability of these steels. Furthermore, we aim to investigate the influence of impurities in the compositions on microstructure and mechanical properties. As a result, the inverse design enables to define mixtures based on recycled steel with mechanical properties that are at least as suited as a prescribed reference material. As one of the main novelties of this project, we plan to address not only stiffness or plastic deformation, but also hardening and strength, i.e., the coupling between damage and plasticity as well as debonding in grain boundaries of novel crossover ASS. Integrated in the overall comprehensive design framework (high-throughput screening, synthesis, and characterization combined with machine learning-based inverse design), this allows us to understand and evaluate the role of scrap mixtures and contained tramp elements on the mechanical properties. In particular, the considered effective properties include damage-resistance, which is prerequisite for designing robust alloys with enhanced sustainability.
DFG Programme
Priority Programmes
