The Effect of Build Strategy on the Residual Stress Distribution in Additively Manufactured Duplex Stainless Steel Pressure Vessels

The resistance to service loads and defects of additively manufactured structures can be significantly reduced due to residual stresses induced by inhomogeneous cooling during the manufacturing process. For duplex stainless steels solution annealing at approx. 1050°C is the only industrially accepted stress relieve treatment. This is often accompanied by severe deformation due to the low creep resistance of the alloy at this temperature. For economic reasons the parts should be used in the as-built state, where the residual stress distribution needs to be considered. We determined the residual stress distribution of simplified pressure vessel geometries using high energy white beam X-ray radiation and the hole drilling method. As a result of this study, two building strategies were evaluated for their ability to produce a compressive residual stress state on the media facing side of the parts.