Measurement of Residual Stresses in Thick Reduced Pressure Electron Beam Welded Components

Residual stresses are introduced into engineering components during welding and are usually considered undesirable. [The knowledge of these stresses can help to determine the structural integrity of the component, and therefore understanding the distribution and magnitude of residual stresses]. In this paper three components (plate weld, pipe weld and curved plate section weld), supplied by Rolls Royce plc, have been welded using the Reduced Pressure Electron Beam technique. Several techniques are available for measuring the residual stresses in welds. However, only the deep hole drilling technique is capable of determining these residual stresses in very thick components. The outcome of the measurement process showed that the tensile residual stresses in the EB welded plate are confined to a region either side of the EB weld that corresponds to about 20% of the wall thickness. Post weld heat treatment in the cuved plate section weld showed significant reduction in the residual stress.