AbstractDetailed finite element modelling is employed to elucidate the residual stress and plastic strain produced during dissimilar friction welding of AISI 304L stainless steel and titanium substrates. Heat transfers into a narrow zone (± 20 mm either side of the bondline) as a result of the friction welding operation. Since titanium has a lower thermal conductivity than AISI 304L stainless steel, higher peak temperatures are attained in AISI 304L stainless steel material in the region adjacent to the bondline. Close to the bondline, the radial component of the residual stress σr is tensile in the substrate with the higher thermal expansion coefficient (AISI 304L stainless steel), and compressive in the substrate with the lower thermal expansion coefficient (titanium). At the periphery of the welded component, the axial residual stress component σz is compressive in the AISI 304L stainless steel near the bondline, and tensile in regions far from the bondline. In titanium at the component periphery, σz i...