Speaker
Description
This contribution combines recent experimental results with literature data to summarize the current understanding of how tramp elements, introduced through the increased use of scrap in steelmaking, affect processability, microstructure, and the resulting mechanical properties of steels. Tramp elements such as Cr, Ni, Sn, Sb, Cu can give rise to a wide range of potential effects, including retardation of diffusion-based phase transformations, incomplete recrystallization, grain refinement, precipitation, grain boundary segregation, or shift of ductile-brittle transition temperature. The main impacts on material performance include strengthening, loss of ductility, and various forms of embrittlement. The likelihood and magnitude of these effects depend strongly on the concentration of tramp elements, the applied heat treatment, and the chemical composition of the steel. Building on the fundamental understanding of how tramp elements influence structure-property relationships, potential mitigation strategies aimed at limiting or counteracting their adverse effects are identified and discussed. Based on the provided results and discussions, it can be stated that in-depth understanding of the impacts of tramp elements combined with tailored counter-measures can support higher scrap utilization rates in circular economy.