Metallographic investigations of dissimilar welded joints of duplex 2205 and austenitic 316L steels

The presented work is the result of the author's investigations connected with the examination of the usefulness of welding methods of dissimilar welded joints for their use in industrial practice. Four different types of dissimilar welded joints were used to determine their weldability as a part of the research program. These joints were made on the basis of typical duplex steel (grade 2205 - X2CrNiMoCuN22-5-3 steel with the number 1.4462) and typical, low-carbon austenitic steel (grade 316L - X2CrNiMo17-12-2 steel with the number 1.4404) using the welding wire Avesta P5. The weldability of investigated joints was assessed with regard to its three basic aspects: metallurgical weldability, technological weldability and technical weldability. Metallographic studies allowed, basing on microscopic studies, evaluating qualitative parameters of the morphology of investigated joints and to indicate some quantitative quantities. In welds welded at lower linear energies, dendrites are less densely packed and are typically column ones. The results of the metallographic studies have shown that low welding energy and a small number of passes result in better morphology of the weld material.