Abstract: In order to further optimize the oxide metallurgy production process withTi-Mg-Ca deoxidization and improve product quality, samples were taken at each process node, and the composition, quantity, size and final effect of oxide metallurgy were analyzed by SEM, OM and Gleeble-3800 dynamic thermal simulation test machine. The type of inclusions was changed from silicon manganese oxide to magnesium aluminum spinel containing titanium, and then to composite inclusions dominated by aluminum titanium calcium oxide. LF and the degassing process of RH had obvious effects of inclusion removal and refinement. Impact work at –40 ℃ of heat affected zone after 150 kJ/cm and 200 kJ/cm welding simulation respectively were 216 J and 208 J. The microstructure of the heat affected zone was mainly acicular ferrite and grain boundary ferrite.

Key words: oxide metallurgy, inclusions, heat affected zone, acicular ferrite