Inclusion morphology control of soft-killed deoxidation spring steel

With different slag basicity and refining process,the total oxygen content,inclusion size,and composition were analyzed,and the morphological distribution of inclusions was studied in the spring steel. The results show that,high basicity slag is propitious to inclusion size control,but high basicity also results in the fragile inclusion in steel,low basicity slag can also cause the relatively high oxygen content and large inclusion in steel. In order to ensure the plastic inclusions in spring steel,the slag basicity should be controlled in 1.0-1.3,and at the same time,the soft blowing time should be prolonged properly to ensure the removal of large inclusion and decrease the oxygen content in steel.