Microstructure Refinement of Medium Carbon Steel through Ti Deoxidation

Abstract

The medium carbon steel (C: 0.26%, mass percentage) was deoxidized by Ti alloys, and its features of inclusion and microstructure were systemically studied through the scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS). The results show that the element of titanium in inclusions coexists with manganese, and no single-phase oxides of titanium are observed. Through the statistical analysis, it can be seen that the average size of Ti-contained inclusions is similar to the inclusions without the Ti, and the percentage of large inclusions (>5μm) is smaller in Ti-contained inclusions, which may reduce the harmful effect of inclusions. After etching in 3Vol% Nital solution, it’s found that the Ti-contained inclusions can act as nucleation sits for the intragranular acicular ferrite.