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[Display omitted] • The wettability of molten iron on the graphite prism plane is better than that of the graphite basal plane. • The wetting process of molten iron on the graphite basal plane is different from that on the graphite prism plane. • The iron atoms in contact with the incomplete carbon structure will exhibit a cluster structure. • The exfoliation of carbon atoms in the basal model is more complicated than that in the prism model. Understanding the mechanism of the iron-carbon reactive wetting process is very important to understand the interaction between molten iron and carbonaceous materials in the ironmaking process. In this paper, the method of ReaxFF molecular dynamics simulation was used to study the microscopic mechanisms involved in the iron-carbon reactive wetting process. The study examines spreading area, contact angle, microscopic atomic structure, and the interfacial processes. It was found that the wetting process between molten iron and graphite is different for the different crystal orientations of graphite. The wettability of molten iron on the graphite prism plane is better than that on the basal plane. However, the degree of corrosion of molten iron on the graphite basal plane is greater, which is directly related to the way of exfoliation of atoms at different crystal orientation planes. The exfoliation of carbon atoms in the graphite basal model is more complicated, and there are two steps. The iron atoms are in contact with the graphite layer, leading to the formation of defects, which in turn destroy the graphite structure. Then, the iron atoms come into contact with the unsaturated carbon in the pores of the graphite, thereby exfoliating the carbon atoms from the graphitic structure. And the carbon atom exfoliation method in the graphite prism model is relatively simple. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper revealed the wetting behavior of molten iron on graphene surface from the atomic scale. • The smoother the graphene, the better the wettability of molten iron on its surface. • The wrinkle amplitude is significantly stronger than the wrinkle frequency for the wetting process. • The better the wettability of molten iron on the graphene surface, the more micro-cluster structures near the interface. Graphene has become a research hotspot in the field of materials due to its excellent properties and unique two-dimensional structure. Metal-graphene nanocomposites are usually formed by dispersing metal nanoparticles on graphene surface. Therefore, the wettability of metal on graphene is an important factor affecting the synthesis. In this paper, molecular dynamics simulation methods are used to study the wetting behavior of molten iron on the graphene surface. The changing law of the wettability of molten iron under different wrinkles of graphene was discussed in depth. The similarities and differences of wetting behavior changes are compared from the perspectives of interaction energy, spreading area, contact angle, interface atomic force and cluster analysis. The results show that the change of graphene wrinkle amplitude and wrinkle frequency have different effects on the variation of wettability. The influence of wrinkle amplitude is obviously stronger than that of wrinkle frequency. And the smoother the graphene, the better the wettability of the molten iron. Therefore, if we want to make iron-graphene composite materials, it is necessary to strictly control the flatness of graphene. [ABSTRACT FROM AUTHOR]

[Display omitted] • The EAM potential is suitable for characterizing the microstructure of liquid Fe-C alloy, while MEAM is not. • EAM potential could accurately predict the melting point of liquid Fe-C alloy. • Increased carbon content helps to increase the complexity of the liquid Fe-C alloy microstructure. • The transformation of Fe4C units to cementite promotes viscosity increase. The liquid Fe-C alloy is the most important system in the metallurgical process and the molecular dynamics simulation were carried out to investigate the structure and properties of liquid Fe-C alloy using EAM and MEAM potential. The local structural order, transport properties and fluidity were analyzed. By comparison, the EAM potential is better than MEAM potential to simulate the properties of liquid Fe-C system. In the liquid state, the Fe-C alloy have a short-ranged ordered structure, accompanied by the transformation of Fe 4 C units to Fe 6 C units with the carbon content increasing. And the increase in carbon content could increase the complexity of the liquid structure. In terms of transport properties and fluidity, there is an inflection point when carbon content increases to 2 wt%. When the carbon content is less than 2%, the change of Fe atom transport performance is the main factor that leads to the increase of viscosity. On the contrary, when the carbon content is more than 2%, the transportation of C atom dominates. [ABSTRACT FROM AUTHOR]

Understanding the interaction of iron and carbon is of vital importance to guide the fundamental research in the fields of metallurgy and materials science. Reaxff molecular dynamics simulation method was used to study the carburizing reaction process between graphite and molten iron. It was found that the rise of temperature can promote the carburization reaction, and the graphite prism model needs to break through a potential energy barrier when the temperature rises to 2000 K, and then carbon atoms can diffuse into the molten iron more easily. Above 2000 K, the carbon saturation of the molten iron of the graphite prism model is significantly higher than that of the graphite basal model, which proves that different carbon materials and contact ways will have different effects on the carburizing results. And it also found that high temperature can promote the mass transfer. In addition, it is found that the carburizing reaction in the graphite basal model mainly occurred in the defect parts of the graphite sheet layer. There are no defects in the graphite prism model, but the carbon atoms can be stripped from the graphite structure in the form of single atoms, diatomic carbon chains and triatomic carbon chains. [Display omitted] • The carburizing process of graphite into liquid iron was investigated from atomic scale. • The graphite different surfaces have obviously different properties. • High temperature were helpful to promote the dissolution process through making the graphite structure unstable. • Carbon atoms dissolved into the liquid iron in the form of single atoms, diatomic chains and triatomic chains. [ABSTRACT FROM AUTHOR]