Abstract: Based on the control of time rhythm，the goals of low cost, high efficient, high quality and energy saving can be achieved in steelmaking system. Aiming at the indefinite furnacecaster corresponding relation in BOF steelmaking plant of Bensteel, seven specialized production lines were established. Such as producing ultralow carbon IF steel, the matching analysis of operation time among BOF, RH and CCM was carried out by applying GANTT diagram. The bottleneck of the previous flow running was the BOF and RH. By increasing the oxygen supply intensity from 2.86 m3/(t·min) to 3.19 m3/(t·min), enlarging the dimension of tapping hole, taking a pre-vacuum operation, rapidly reaching the limit vacuum and increasing the lifting gas amount at later stage of decarburization, BOF and RH process cycles were shortened. Consequently, production rhythm was precisely lowered to (32±2) min from averagely 45 min by employing the technology of constant casting period which was first put forward. The precise and specialized steelmaking was realized.

Key words: ultra-low carbon IF steel, specialized production line, rhythm matching, constant casting period, precise production