The transformation of MgO· Al2O based inclusions in alloy steel during refining has been studied by in- dustrial trials. Besides Factsage software is used to sttidy the formation and modification of spinel inclusions in alloy steel using calcium treatment during refining process. The results show that the transformation sequence of inclu- sions is：MgO· Al2O→CaO-Al2O3-MgO complex inclusions--→MgO· Al2O, and under present experimental con- dition, in order to avoid forming MgO· Al2O inclusions the content of dissolved Ca in the molten steel has to reach 1 × 10-6. Also the results show that when more calcium was added to molten steel, the content of Alz 03 and MgO will be lower. Besides, increasing the content of CaO in the inclusions will increase even if tlae content of SiO2 changes little.
YANG Shu-fengLI Jing-sheZHANG Li-fengKent PeasleeWANG Zai-fei
