Développement d'aciers renforcés avec des carbures primaires par voie métallurgique liquide conventionnelle

The improvements that could be obtained in the properties of cast structural alloys through the reinforcing its matrix with hard, microscopic and dispersed ceramic particles (TiC, VC, NbC), are accepted and recognized. In this sense, the development of a liquid metallurgy process enabling the reinforcement by means of the addition of the ceramic material to the molten metal in the melting furnace would become an important advance in the metallic materials field. Nevertheless, these ceramic products are prone to the coalescence and have pour wettability into molten baths as steel, superalloys, etc., so that the resulting operation yield and the subsesquent property improvement are very low. In order to solve these disadvantages, we have developed a liquid metallurgical process allowing to make steel products with a composed microstructure of martensitic matrix and discrete primary carbides (MoTi)C metallurgically embedded in rt. This process includes the following fundamental steps: previous preparation of the material of reinforcement, in this case of Fe(MoTi)C type. melting of the steel bath by means of conventional electric furnaces. addition of the carbide particules material to the molten steel bath, pouring, solidification and heat treatment.