Analysis of Dynamic Conditions of Electric Arc Furnace Steelmaking

The poor kinetic conditions of the metallurgical reaction in the molten pool have always been a technical problem in electric arc furnace steelmaking. 

The lack of agitation strength of the electric arc furnace steelmaking bath has a lot to do with the characteristics of the furnace type. The traditional electric arc furnace uses scrap steel as the basic raw material, mainly uses electricity, and is supplemented by chemical energy to produce qualified molten steel. 

Therefore, the furnace design has Features of large furnace and shallow molten pool. The height-to-diameter ratio of a 100t electric arc furnace is only 53% of that of a converter with the same capacity.

Generally speaking, the greater the ratio of height to diameter, the greater the oxygen supply strength that can be withstood. Considering the influence of scrap melting and slag flow from the furnace door, the stirring strength of the electric arc furnace bath is further restricted, which is only 10%-20% of that of the converter. .

The stirring strength of the molten pool can be described by the flow rate of molten steel. A numerical simulation method was used to simulate the flow of molten steel in a 100t electric arc furnace. It was found that the average flow velocity of molten steel in the electric arc furnace was 0.06m/s, while the average flow velocity of molten steel in a 100t converter was 0.31m/s. The stirring strength of the molten pool of the electric arc furnace is very different from that of the converter. In actual production, compared with the converter steelmaking, the smelting consumption and production cost gap between electric furnace steelmaking and converter steelmaking is obvious.

At the end of steelmaking, carbon and oxygen content, oxygen content, and slag (FeO) content are important indicators that reflect the stirring strength of the molten pool, and have a significant impact on the quality of the product. Using data provided by many advanced steel companies such as the end point carbon content, oxygen content, and final slag (FeO) content of electric arc furnace and converter smelting, the study shows that the average end point carbon oxygen content of electric arc furnace steelmaking is about 0.0032, and the average final slag ( The FeO content exceeds 22.00%, which is higher than that of converter steelmaking.

In summary, due to the limitations of furnace type and smelting process, the low stirring strength of the electric arc furnace bath restricts the technological progress of electric arc furnace steelmaking.