M7C3 carbides (where M could be Fe, Cr, i.e. (Fe, Cr)7C3) or other solution elements replacing Cr or Fe are a special group of carbides, widely used in materials such as white cast iron and welded hardfacings. Normally, the structure of hypereutectic Fe–Cr–C alloy consists of a high quantity of large primary M7C3 carbides within an eutectic matrix. The morphologies of primary M7C3 carbides directly influence the hardness, wear resistance, fracture toughness of the alloy as well as the physical properties such as thermal conductivity and electrical resistance. It is essential to develop a systematic data-led modelling framework to assess the effect of the morphologies on the key properties and functionalities of M7C3 carbides under different loading conditions.

In this paper microstructure based modelling is applied to M7C3 carbides. An effective framework has been developed to transfer microstructure of M7C3 carbides into image databases for statistical structure analysis and modelling. A mechanical-thermal-electrical modelling approach has been developed and is applied to different carbide structures for predicting the effective properties including stiffness, thermal and electrical properties. A new approach is developed to model the structure of individual carbides including the stress concentration factors associated with the shapes and the internal features, which is critical to wear and fracture of the carbides. The key functional feature of the program is presented including microstructure data, image processing and structure models with different scales. The work show that the internal feature could cause significant variation of stress concentration factors under different loading and boundary conditions. The key issues in data development and analysis of the structures are outlined. The link between engineering simulation and first principle calculation of the properties is analysed. The use of modelling for data-driven materials development, quality and performance prediction is discussed.