Study and Application of Catch Carbon to Produce High-Carbon Steel on 210 t BOF

Catch carbon is used to produce high carbon steel with double slag and catch carbon and re-blowing practice.Phosphorus removal is very crucial for refining non-dephosphorized hot metal to produce high carbon steel.The phosphorus content in hot metal was decreased from 0.078%-0.094% to 0.027%-0.038% in 5 minutes using double slag method.When the carbon content of 0.8%-1.1% in steel and phosphorus content could be reduced to 0.014%-0.023% using catch carbon and re-blowing method.Thus 0.4%-0.7% tapping carbon content and less than 0.015% phosphorus in final product could be reached by using these two methods together for theirs lower tapping phosphorus due to less rephosphorization after tapping.The high oxidizability of ths slag at high carbon content in steel benefits phosphorus removal.After the application of this method,the average tapping content of carbon was increased from 0.22% to 0.4%,the total oxygen content and nitrogen content decreased by 1.6×10-6 and 5.1×10-6 respectively in average.