核电蒸汽发生器传热管/管板接头传热管内壁的焊接残余应力分布

采用自行搭建的管道内壁残余应力测试平台,通过切割法测得核电蒸汽发生器传热管/管板接头传热管内壁的焊接残余应力,结合有限元模拟,研究了传热管内壁焊接残余应力的分布规律。结果表明:试验测得传热管/管板接头中传热管内壁近焊缝处的轴向和周向残余应力均为拉应力,随着距焊缝中心线距离的增加,残余拉应力减小并变为压应力,在距离焊缝中心线12mm处,残余压应力最大,在距离焊缝中心线21mm处残余应力减小至焊前初始应力;传热管内壁焊接残余应力分布的模拟结果和试验结果基本吻合,该有限元模型可以准确模拟核电蒸汽发生器传热管/管板接头传热管内壁焊接残余应力的分布规律。

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.