Development and Application of a Hybrid Mechanistic-AI Model for Flux Optimization in High-Scrap-Ratio Converter Steelmaking of High-Manganese Steel for LNG Tanks
摘要
Driven by the needs of low-carbon transformation and cost reduction with efficiency improvement in the iron and steel industry, converter smelting with a high-scrap ratio faces the dual challenges of large deviations in energy consumption calculation and unstable control of flux addition. To address the operating condition issue of the 120-t converter, this paper clarifies the intrinsic correlation among molten pool heat demand, slag material consumption, and heat compensation measures under high-scrap-ratio (25–45 pct) conditions by analyzing the “heat–material–oxygen” coupling relationship in the converter’s smelting heat and material balances. Based on key on-site production data from 1200 heats, after data preprocessing, a collaborative system for predicting the optimal flux addition amount, combining a mechanism-based model with an intelligent algorithm, was constructed. Pearson correlation analysis combined with the recursive feature elimination (RFE) algorithm was used to screen 8 key characteristic parameters, including scrap weight, hot metal Si content, and charging weight. Comparative analysis of BP, PSO-BP, and GA-BP models reveals that the GA-BP model performs best, achieving a Goodness of Fit (R2) of 88.3 pct, a Mean Absolute Percentage Error (MAPE) of 0.12 pct, and an RMSE of 206.4 kg. Industrial implementation in a 120-t converter demonstrates that model-guided prediction increased the comprehensive end-point hit rate from 82.4 to 91.5 pct (a 9.1-pct absolute improvement). Statistical validation across 1000 heats confirms that the model effectively stabilizes flux additions by eliminating the “positive bias” (the tendency of over-adding lime/dolomite) found in manual operations, thereby reducing manual dependence, and lowering production costs, providing robust technical support for the green and efficient production of high-manganese steel for LNG tanks under high-scrap-ratio conditions.