Data-Driven Control of Longitudinal Crack in Medium Carbon Steel Slabs: A Causal Learning Framework Integrating DAG and DML
摘要
In intelligent manufacturing, embedding domain knowledge into data-driven models is essential for interpretable and causally grounded process control strategies. This paper proposes a causal learning framework that integrates Directed Acyclic Graphs (DAG) with Double Machine Learning (DML) to uncover causal pathways from process inputs to product quality. Unlike conventional black-box models, the framework explicitly encodes the causal chain “raw material addition→ chemical composition→ crack formation”, enabling both interpretable analysis and actionable optimization. The framework was validated through a case study on longitudinal crack control in the continuous casting of medium-carbon steel. The framework identifies Ca, Als, Ti, and Mn as the key elements influencing crack formation via combined ATE and SHAP analysis. The partial dependence plots of SHAP value quantify their optimal compositional ranges for defect suppression: when the content of Als is 0.014 to 0.019 wt pct, Ca is 0.0001 to 0.0012 wt pct, Ti is 0.031 to 0.040 wt pct, and Mn is 0.23 to 0.49 wt pct. The inverse optimization grounded in DML models translated the identified optimal compositional targets into precise, industrially actionable raw material addition specifications: 0.7769 to 1.0930 kg/t pure calcium wire, 0.5304 to 1.1872 kg/t calcium carbide, 42.4741 to 49.7741 m3/t oxygen, 0.1696 to 0.7179 kg/t high-carbon ferromanganese, 0.7446 to 0.9263 kg/t titanium iron, and 0.8998 to 1.6139 kg/t aluminum wire. The framework demonstrates strong generalization capability across both test set and an independent production period, offering a generalizable paradigm for integrating domain knowledge with causal machine learning in intelligent manufacturing processes.