Five data sets, each containing a year’s worth of electric arc furnace (EAF) steel production, were analyzed for electricity consumption trends using a literature multilinear regression (MLR) model, a modified MLR model with engineered variables, and a machine learning (ML) model utilizing XGBoost and Shapley analysis. While the literature model provided a stronger fit to data, the engineered model resulted in more physically probable results and is recommended due to a wider applicability. The results of the ML analysis provided an auxiliary analysis that confirmed several accuracies in the engineered model; however, the results exposed some weaknesses of the model, namely its sensitivity to outlier data points. It is determined that the analysis of EAF electricity usage is most effectively done by utilizing the MLR with engineered variables in conjunction with an ML analysis.
ABSTRACT In shougang ironmaking system, the key technologies are researched and developed, the advanced engineering integration system is designed and constructed. It configures a high pellet charging ratio and high efficiency low carbon smelting process system, to realize the ironmaking process dissipation system optimization. The technical characteristics of Shougang’s blast furnace include improve the blast oxygen enrichment ratio, reduce the blast volume and bosh gas volume, improve the PCI amount and top pressure, as well as raise the hot blast temperature steadily. The comprehensive technologies of thick material layer sintering and hot air circulation has realized the reduction of resources and energy, and effectively reduced the emission of CO2 and pollutants in the sintering process. The travelling grate induration machine is applied to produce high quality and high performance pellet, the preparation and application technology of alkaline pellet are developed and applied, which establishes a technical foundation for the blast furnace ionmaking of high proportion of pellet charging.
Excessive CO2 emissions due to consumption of fossil fuels is one of the major causes of global warming. The iron and steel sector accounts for 7-9% global anthropogenic CO2 emissions according to World Steel Association, and 7% of total CO2 emissions from the energy system according to International Energy Agency (IEA).1-2 Significant reduction of CO2 emissions in the production of iron and steel is highly demanded and has become a great challenge to the steel industry.
ABSTRACT Direct Reduced Iron (DRI) is one of the key methods of decarbonization for the global steelmaking sector. While much literature exists on the emissions reductions associated with using DRI for ironmaking, less attention has been paid towards the increased emissions required to produce DRI-grade feedstock compared to lower quality iron ore feed. This paper aims to provide an overview of the emissions associated with generating high-quality DRI in several locations to provide a reference for more accurate estimation of emissions associated with adopting DRI. The calculated equivalent carbon emissions for the production of DR grade oxide pellets is approximately 200 kg CO2/mt pellets, representing a significant portion of DRI based steelmaking emissions.
New advanced high-strength steels (AHSSs) based on different microstructure-based concepts have been developed in the past decades to meet various needs in the automotive industry. Nevertheless, cracking issues in many practical forming and crash scenarios still limit the applications of these new AHSSs, despite their relatively high tensile elongations measured under laboratory test conditions. Accordingly, and inspired by the concept of the Local-Global Formability Diagram, this work started from comparing true fracture strain (TFS), a typical representative parameter of the local formability/ductility, of different AHSS sheet-metal grades. Furthermore, possible TFS evolution by some critical application-based effects, such as temperature, bake hardening, and strain rate was investigated. Explanations and discussions of the material mechanisms based on the test results were also presented in this work. The ultimate objective of this study is to highlight the importance of local formability/ductility and provide the corresponding references to the future AHSS development strategy.
