Effect of Al Content in Steel on Interfacial Interaction between Molten Steel and MgO Substrate

作者：Lao, Yigui; Gao, Yunming^*; Yuan, Cheng; Li, Guangqiang^*

来源：Steel Research International, 2023, 94(6).

DOI：10.1002/srin.202200778

• [Al] contents
• interfacial interactions
• microporous magnesia aggregates
• molten steels
• sessile drop method
• wetting behaviors

The apparent contact angles between the molten steel with different [Al] contents (w([Al])) from 0.002% to 0.831% (mass fraction) and the microporous MgO (MM) substrates are measured at 1823 K using the sessile drop method. In particular, the contact angles of No. 1 (w([Al]) = 0.002%) and No. 5 (w([Al]) = 0.831%) molten steels gradually increase with time at the initial stage. As w([Al]) increases from 0.002% to 0.831%, the transformation route of interfacial products between molten steel and the MM substrate is MgO-FeO -> MgO center dot Al2O3 -> CaO center dot 2Al(2)O(3) + MgO center dot Al2O3. The w([Al]) of No. 1 molten steel is small, and the dissolution of CaO center dot ZrO2(s) in the substrate is mainly affected by FeO. As w([Al]) increases gradually, [Al] consumes the (MgO) contained in CaO center dot MgO center dot SiO2 (CMS), and turns the CMS into (CaO center dot SiO2) slag layer, which promotes the CaO center dot ZrO2(s) dissolving and thus increasing the interaction area percentage. When w([Al]) is 0.831%, [Al] can react with (CaO center dot SiO2) slag layer or CaO center dot ZrO2(s) to form CaO center dot 2Al(2)O(3)(s).