A welded joint between at least one metal material element and at least one thermoplastic material element is obtained by pressing the elements against each other while applying heat. Contact surfaces of the metal material, which are in contact with the thermoplastic material, are provided with uneven surface portions having a distribution of asperities. With heat applied, the thermoplastic material fills spaces between these asperities and maintains this configuration after subsequent cooling, thereby improving strength of the joint. The uneven surface portions are obtained in a preliminary forming step of the metal material in a press mold, which is configured with a forming surface for generating the uneven surface portions by mechanical deformation and/or with a device for guiding a laser or electron beam. By this technique, hybrid components are obtained made of one or more elements of metal material between which a shaped component of thermoplastic material is interposed.