Modification of Inclusions by Adding Mg to 16MnCrS5 Gear Steel

The strength, ductility, and cutting performance can be seriously affected by the size and distribution of inclusions in the steel. Using a high-temperature tube electric resistance furnace, the effect of Mg addition on the evolution of inclusions in 16MnCrS5 steel was investigated. Besides, the deformation behavior of inclusions was carried out by a simulated testing rolling mill (Gleeble-3500). The results showed that the ratio of compound inclusions (MgO·Al2O3 wrapped by MnS) increased after Mg addition in steel, and the same trend was obtained in the aspect ratio of inclusion together with the ability of resisting the deformation of inclusions after hot-extruding. With the increasing of Mg addition from 8 ppm to 42 ppm, the mean area of inclusions in experimental ingots first decreased and then increased. Additionally, the peak mean area of inclusions occurred under the Mg content of 35 ppm.