Residual stress measurement on Titanium Grade 5 and Inconel 625 thin dissimilar welded joints by contour method

Residual stress assessment is a key factor in engineering design owing to its impact on engineering properties of materials, structural components and welded joints. In dissimilar welding, residual stresses arise due to both the welding process itself and the different coefficients of thermal expansion of the two welded materials. The longitudinal residual stresses in 2-mm-thick laser-welded Ti–6Al–4V and Inconel 625 plates with two intermediate inserts of Vanadium and steel were determined using the contour method and the X-ray diffraction. For all the specimens analyzed, the contour method stress maps revealed that the highest tensile residual stress zone occurred in the steel insert, while compression was found in the base metals. Moreover, harmful surface tensile stresses arose at the welds between steel and Vanadium. Lastly, among the three welding schemes examined, the dissimilar joint realized with the AISI 316L insert exhibited the lowest harmful surface tensile residual stresses. Graphical abstract: [Figure not available: see fulltext.]