Aluminium-steel plating by press welding

Abstract

A series of researches related to aluminium-steel plating by press welding are presented in the paper. In this sense, the influence of the roughness of the aluminium and steel test samples was taken into account, but also of the post-welding heat treatment on the characteristics of the joints made. S355 steel specimens and AlMgSi0.7 F27 aluminium specimens were analyzed. The samples were processed and roughness Ra = 2.51-51.09 µm were obtained. Also, after making the joints, a postwelding heat treatment was applied which consisted of a heating at a temperature of 425 °C with a duration of 6.5 hours and a slow cooling to room temperature. Six distinct samples were made in terms of surface roughness in the joint area. After making the joints and applying the heat treatment, the samples were analyzed in terms of metallographic structure, the thickness of the interface layer and the hardness of the material in it. Thus, it was found that both the roughness of the test tube surfaces and the post-weld heat treatment have a substantial influence on the metallographic structure and the hardness of the material in the interface layer. The highest hardness of the material in the interface layer and its lowest thickness were obtained for the samples with the lowest roughness of the joint surfaces.