Recently, automotive steel with a scrap steel ratio of 42% rolled off the production line at the rare earth steel plate plant, marking the successful trial production of automotive steel with a high scrap steel ratio by Baogang and the company's green and low-carbon manufacturing capabilities have reached a new level.
Scrap steel is a renewable resource and one of the important steel materials in the steel production process. Compared with iron ore, it has the characteristics of green and renewable. In theory, using scrap steel to produce 1 ton of steel can save 1.6 tons of iron ore, and 0.35 tons of standard coal, and reduce carbon dioxide emissions by 1.6 tons and solid waste by 3 tons. Therefore, increasing the scrap-steel ratio is an important measure for resource recycling and an effective way to achieve carbon emission reduction and promote green development. Under the current background of environmental protection, low carbon, and green development, automobile manufacturers have an increasingly strong demand for low-carbon automobile steel. Rare earth steel plate plants implement the national "dual carbon" goals and actively explore large scrap steel ratio smelting technology, especially in creating low-carbon automobile steel products, and strive to increase the "green content" of products.
For a long time, the production of automobile steel in rare earth steel plate plants only added scrap steel during the converter smelting process, and the scrap steel ratio was usually controlled at around 22%. In order to increase the scrap steel ratio, the plant benchmarked the industry's advanced standards, innovated the smelting process, formulated a test plan, and scientifically planned the process route, raw material conditions, and test steps. Before trial-producing automobile steel with a large scrap steel ratio, the trial production of a transitional steel type - a large scrap steel ratio ordinary carbon alloy steel was completed.
During the trial production of automobile steel with a large scrap ratio, scrap steel was added to the molten iron at the pouring station, before adding iron to the converter, and during the refining process. For the first time, scrap steel was added to the entire process of automobile steel smelting, and the scrap steel ratio reached 42%, a record high. Considering the impact of adding scrap steel on smelting temperature and product composition, this trial production mainly optimized heat balance, oxygen supply system, slag retention method, slag-making system, endpoint control, etc., and found the point of convergence between low-carbon production and quality assurance.