Effect of the Ti, Al Contents on the Inclusion Characteristics in Steels with TiO₂ and TiN Particle Additions

The effect of the Ti, Al contents on the metamorphic evolution of inclusions of Ti–Al complex oxides including TiN and MnS are investigated in common carbon steels with TiO 2 and TiN particle additions. The study is carried out based on both SEM‐EDS analyses and Thermo‐Calc equilibrium calculations. Moreover, the particle size distributions are investigated by using the electrolytic extraction method. Based on the results of this study, the following is suggested: (i) the steel composition is controlled to contain small amount of the Al content (<0.005 mass%) and large amount of the Ti content (>0.035 mass%) in order to obtain a high number of fine particles containing a Ti‐rich oxide phase when adding TiO 2 and TiN particles; (ii) this consideration is reasonable from the view point of the agglomeration degree of different inclusion materials, which are estimated from the attractive force (van der Waals force and liquid‐capillary force) and the contact angle.