FRICTION STIR WELDING OF CARBON STEEL AND AUSTENITIC STAINLESS STEEL

Abstract

• Friction stir welding (FSW) was invented for the purpose of joining metals which were known to be non-weldable such as some aluminum alloys. FSW has rapidly progressed into a viable joining technology for a variety of metals and alloys. • FSW provide a solution to weld dissimilar alloys which are difficult to be welded by conventional processes. • In the present work, FSW was used to weld 3 mm thick St37 carbon-steel and 304 austenitic stainless-steel • A tool of tungsten carbide was used for welding due to high melting point of steel. • Welded joints were inspected with visual inspection, radiography, and macrostructure. • The mechanical properties of the joints in terms of tensile and hardness testing were also conducted. • Further studies were applied using an optical microscope and XRD to examine the microstructure of the joints. • Different microstructural regions were obtained due to the influence of tool rotation, vertical force and generated heat.