Quantitative Evaluation of the Influence of Microstructures on Cleavage Fracture Toughness in Ferrite-Cementite Steel

摘要

A numerical model is proposed to quantitatively predict the influencernof microstructures on fracture toughness of ferrite-cementite steel. Arnprocess of cleavage fracture initiation is assumed to be composed of thernthree stages; (I) cementite cracking, (II) propagation into ferrite matrixrnand (III) propagation across grain boundary. The model is developedrnconsidering statistical distributions of microstructural factors.rnNumerical results of the fracture toughness show good agreements withrnexperimental results. Bottle neck process of the fracture can bernestimated by the proposed model.