TEM Study of Nanoprecipitation and Dislocation Interactions in Novel Cold Rolled "Nano-Steel"

Over several years, automotive and steel-making industries have continuously conducted research to reduce fuel consumption, CO2 emissions, cost production, raw material and steel consumption. Nano- steels strips, developed for light-weight automotive applications, are a new generation of Advanced High Strength Steels (AHSS), developed to meet these demands. In this research, cold-rolled micro-alloyed single-phase V and Nb-bearing ferritic strip steels are studied to follow and fully characterize nano-precipitates evolution, as well as their interaction with dislocations and matrix. This investigation, confirmed the presence of fine ( 100 nm) and ultra-fine ( 10 nm) precipitations predominantly rich in both V and Nb (as indicated by TEM-EDS examination), as well as their interplay with the most representative dislocations structures (tangles and walls).