Abstract: Accurately and overall evaluating the comprehensive metallurgy status of base iron is the basis and guarantee for effective implementation of nodularization and inoculation treatment in ductile iron production. The establishing method of a comprehensive characterization parameter system and the corresponding evaluation model for the metallurgical status of base iron for ductile iron are studied based on the correlation degree theory in the grey system. Then, the beneficial effects and application conditions are analyzed. The main steps include:Constructing a comprehensive evaluation parameter system; Establishing the grey correlation model for metallurgical status evaluation of the base iron; Determining classification grades of the metallurgical status according to the comprehensive evaluation value calculated form the correlative evaluation model, and the adjustment plan for metallurgical status could be made according to each correlation coefficient value of single evaluation parameter. The simulation application results in laboratory condition show that the grey correlation degree value could be used to effectively evaluate the relative metallurgy quality status of the base iron. A single correlation coefficient value from each evaluation parameter could characterize the close degree to the optimal value of this characteristic parameter in the production conditions, but did not entirely determine the final nodularization effect. Under the condition of stable production, the predictive accuracy of evaluation model for divided "four grades" of base iron quality of ductile iron can reach more than 90%.

Key words: ductile iron, grey relational analysis method, metallurgy status of base iron