On a Cloud Group of Inclusions formed during Deoxidation of Liquid Iron with Aluminum

The formation of oxide inclusions were investigated by dropping an aluminum bar to static liquid iron in which oxygen was dissolved, in order to examine the effects of the reaction time and the initial oxygen content on its formation. The results were: (1) In most specimens, alumina inclusions were formed in distinguishable layers. (2) The thickness of the stratiform inclusions group increased with the reaction time, independent of the oxygen content. (3) With increasing oxygen content, the inclusions became larger and more numerous. (4) The inclusions group did not exist at Grube’s contact surface, but in the area with less than 13% aluminum in liquid iron. (5) The apparent diffusion coefficient of aluminum in liquid iron decreased with the formation of inclusions.