Welding Residual Stress Distribution of Heat Transfer Tube Inner Wall of Tube-to-Tubesheet Joint in Nuclear Steam Generator

The welding residual stress on heat transfer tube inner wall of tube-to-tubesheet joint in nuclear steam generator was measured by cutting method with a self-built test platform for measuring the residual stress on the inner wall of the tube. The welding residual stress distribution on the heat transfer tube inner wall was studied by combining with finite element simulation. The results show that both tested axial and circumferential residual stresses near the weld of heat transfer tube inner wall of tube-to-tubesheet joint were tensile stresses. With the increase of distance from the weld center line, the residual tensile stress decreased and then changed to compressive stress. At the distance of 12 mm from the weld center line, the residual compressive stress was the largest, and at the distance of 21 mm from the weld center line, the residual stress decreased to the initial stress before welding. The simulation results of welding residual stress distribution on heat transfer tube inner wall were basically in agreement with the experimental results, indicating that the finite element model could accurately simulate the welding residual stress distribution on heat transfer tube inner wall of tube-to-tubesheet joint in nuclear steam generator.