Analysis of Copper Effect on Microstruct

Over the past three decades, microalloyed steels have garnered substantial attention due to their exceptional strength, toughness, and weldability properties. This study aims to investigate the effects of a small amount of copper (0.4 wt%) and varying niobium content (0.07–0.09 wt%) on the microstructure and mechanical properties of microalloyed steels undergoing cool deformation conditions. To achieve this, three steel grades were examined, including a commercial steel from IPSCO Inc. and two laboratory-prepared steels, evaluated for their chemical compositions and microstructural characteristics. The focus was placed on the interactions between residual copper and niobium in the context of grain refinement and precipitation strengthening mechanisms. Experimental procedures involved rigorous thermomechanical treatments designed to elucidate the behavior of Nb(C, N) particles during processing, as well as their influences on grain growth during recrystallization. The results showed that the presence of copper adversely affected the mechanical properties while enhancing the steel's susceptibility to grain refinement. This research has significant implications for the recycling of steel scrap and the efficient use of alloying elements in modern steel production, contributing to advancements in material performance.