Evaluation and measurement of the residual stresses in stainless steel pipes and investigation of the effects of wall thickness on the stresses distribution

In this paper, thermo-mechanical behavior of the welding process was analyzed to determine the effect of wall thickness on the residual stress magnitude and distribution in the stainless steel pipes. In order to verify the model, experimental data for the steel pipes, obtained by Deng with deep hole drilling method, were utilized. Good agreement was observed between the finite element and experimental data. The results indicated that the developed computational method is an effective tool to predict the residual stress of similar weld joints. The present finite element model was developed in a butt-welded pipe to consider the effect of pipe wall-thickness. It was observed that by increasing the preheating temperature in the repair welded pipes, tensile axial residual stresses on the inner surface and compressive axial residual stresses on the outer surface of the stainless steel pipes decreased about 35 and 25 percent, but the compressive axial residual stresses on the inner surface and tensile stresses on the outer surface have small variation. Moreover, by increasing the wall thickness of pipe compressive hoop residual stresses on the inner surface on the stainless steel increased, but only a small variation was observed on the tensile hoop residual stresses. In general, there is no significant effect on the magnitude and distribution of hoop residual stresses on the inner surface of the stainless steel pipe. Also, high wall thickness will have wider distribution of axial residual stresses.