Ultrahigh-strength surfaces on novel corrosion resistant hybrid steel

Research Project, 2024 – 2027

Hybrid Steels are a new class of materials recently developed by Ovako that have high fatigue strength, good heat resistance and corrosion properties. The strength depends on an even distribution of very small, precipitated compounds in the form of intermetallic particles and secondary carbides. While precipitate formation and bulk properties have been studied, the possibility of forming an ultrahigh-strength surface remains so far unexplored. Due to the formation of ultrahigh-strength surfaces during hard machining, the component would withstand higher mechanical loads and have improved wear properties, which would increase the surface integrity and thus the life of e.g. bearing in service. The idea is to form the ultrahigh-strength surface during the machining operation, i.e. eliminating the need of an additional coating, which would facilitate recycling after use. In order to determine whether functional surfaces can be formed, detailed characterization of the internal stresses, the microstructure formation and its thermal stability is required (XRD, SEM, TEM, atom probe, synchrotron measurements). Therefore, this project, involving a PhD student over 4 years, is expected to provide detailed knowledge on the materials science of this new steel grade and the development of a guide/model description for the formation of ultrahigh-strength surfaces. The realization of a functional coating on the surface would promote sustainability and circularity.