Atomic‐Scale Insights Into Tramp Element Segregation and Mechanical Performance of a Low‐Carbon Steel

The increasing reliance on scrap in steelmaking in order to reduce CO 2 emissions leads to elevated concentrations of tramp elements, which can significantly influence microstructural evolution and material performance. The effect of higher tramp element levels on segregation of specific elements to grain boundaries, accumulation at ferrite–cementite interfaces within a pearlitic microstructure, and formation of nanoscale precipitates is systematically investigated using atom probe tomography combined with correlative transmission electron microscopy. Detected trends in the distribution of tramp elements are correlated with the changes in mechanical properties measured by hardness and notch impact tests. Pronounced segregation of Cu, Mo, and P was observed at random high‐angle grain boundaries, while Cr, Cu, Mo, and P were additionally enriched at ferrite–cementite interfaces. Moreover, co‐precipitation of Cu, Sn, Ni, and Al at ferrite–cementite interfaces reveals complex interactions between elements. An unexpected improvement in toughness is attributed to enhanced GB cohesion due to Mo segregation and grain refinement. These findings advance the understanding of nanoscale tramp element behavior in recycled steels and provide guidance for alloy design and processing strategies to control scrap‐derived impurities, thereby promoting more sustainable and circular steel production.