Acquiring high density of ultrafine second phase nanoparticles quickly in low carbon steel

In the general smelting process, non-metallic compounds exist in the form of inclusions, which will damage the mechanical properties and life of steel. However, when the size of the inclusion is nanometer, the formation of a high-density distribution of second phase nanoparticles in the steel can effectively improve the strength and toughness of the steel. In this paper, Fe-0.04C-1.5Mn-0.5Ti-0.5Al2O3 (Fe–TAMO) steel was prepared in a very short time by applying a dynamic magnetic field in the smelting process, and then the grain size optimization and equiaxed optimization of Fe–TAMO steel were realized by rolling and annealing. The ultrafine second phase particles densely dispersed in the as-cast matrix were observed by transmission electron microscopy, and the average diameter of the particles was 2.75±0.803 nm. According to EDS spectrum analysis, the second phase particles are complex oxides of Ti-Al-Mn-O. The compressive mechanical properties of Fe-TAMO ferrite steel in different states were tested using a universal testing machine. This method greatly simplifies the process, and the large size inclusions can be removed after one quick smelting, and the ultrafine second phase nanoparticles can be uniformly dispersed in the steel matrix.