EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In the paper the effect of welding technology on the microstructure and mechanical properties of butt welded joints was presented. Metallographic examinations based on light microscopy and SEM were conducted on butt welded joints of 316Ti stainless steel. For each of the weldments, detailed analysis was conducted on the phase composition, microstructure characteristics and mechanical properties. Research has shown that microstructure of the heat affected zone (HAZ) and fusion zone of EB, TIG, PAW and MIG welded joints is not homogeneous and depends on the thermal history of each area during each welding processes. The change in the cooling rate has influenced the grain size which has in turn influenced the mechanical properties. It is observed that the fusion zone has epitaxial grain growth. The metallurgical factors such as the presence of the ferrite and its percentage were also considered to substantiate the variation in the characteristics of the weld metal. The least delta ferrite is contained in the weld of 316Ti steel made using the EBW method – approx 2%, in the MIG method it was about 4%, and the remaining TIG and PAW welds contained from 4 - 5% of the ferry delta.
The results of mechanical properties of butt welded joints are also presented. The hardness and strength of arc welded joints depend on welding technology were presented.