Requirements for Carbon Additive in BOF Steelmaking
The main principle of basic oxygen furnace (BOF) steelmaking is to charge oxygen into the molten iron smelting process, so as to further oxidize and eliminate the impurities, and finally obtain qualified steel. In the BOF steelmaking process, the optimal temperature needs to be maintained, and for this purpose, some additional carbon sources, such as adding carbon additives, need to be used to help achieve this.
The purpose of adding carbon additive in the BOF steelmaking process is to adjust the carbon content of the steel, so that the slag becomes a good liquidity, forming a slight reducing atmosphere, and protecting the molten steel against oxidation. Therefore, the addition of suitable carbon additive can reduce the oxygen levels in molten steel, reduce the formation of tag and reduce the cost. Beyond that, the addition of carbon additives can also reduce the loss of advantages and/or other elements such as boron, titanium and vanadium that were added.
When choosing a carbon additive there are several important considerations to bear in mind. Firstly, the suppliers of the carbon additive should be carefully evaluated, as the quality of the final steel is a direct reflection of the quality of the additive used. Generally, the carbon additive used should have an average particle size of less than 20 mesh, and should have a low chlorine and sulfur content, to ensure that the molten steel is not contaminated by these elements.
Secondly, as mentioned above, the addition of carbon additives into the BOF steelmaking process can protect the molten steel from oxidation, and therefore the carbon content of the steel is an important factor to consider. For general high-alloy steels, a carbon content below 0.10% is required for optimal protection, but for special low-alloy steels, the carbon content should be below 0.05%.
Finally, it is also important to keep an eye out for inclusions and impurities that may be found in the carbon additive used, as these can result in the appearance of non-metallic inclusions in the steel, leading to a decrease in steel quality and yield. Therefore, careful selection of a carbon additive can help ensure the highest quality of steel.
In conclusion, when choosing suitable carbon additive for BOF steelmaking process, it is important to consider the supplier and quality of the additive, the carbon content of the steel, and any potential inclusions and impurities found in the additive. By carefully considering these points, it can help to ensure that the highest quality steel is yielded.
