MANUFACTURE OF PURIFIED STEEL

PURPOSE:To reduce the oxygen contents in a steel and to manufacture the steel having high purity by adding Ca-Si to the molten steel having regulated sol Al contents and discharged to a ladle and regulating the time of Ar bubbling and the ratio of Ca/Al. CONSTITUTION:The steel having 0.010-0.050wt.% regulated sol Al is discharged to a ladle from a steel manufacturing furnace such as a converter. Ca-Si is added to the molten steel in the ladle and Ar gas bubbling is executed for >=3min to regulate the ratio of Ca/Al to the range of 0.03-0.10. In this way, the promotion effect in floating of the inclusions such as Al2O3 is increased, by which the oxygen contents in the steel are reduced and the steel having high purity can be obtd.