水轮机过流部件堆焊变形分析

【作者】 鲁仁全；

【导师】 王希靖；

【作者基本信息】 甘肃工业大学 ， 材料加工工程， 2001， 硕士

【摘要】 黄河上游各大水电站的水轮机过流部件由于多年的泥沙磨损和气蚀破坏，其原设计形状发生改变。在用带板堆焊技术修补水轮机活动导叶时，由于导叶正反面堆焊的位置不同，而产生了不同程度的弯曲，特别是轴向最大挠度（＞0.5mm）不能满足水轮机导叶正常运转。人们在用图解解析法计算模型计算焊接变形时假定了μ_xα/cρ（μ_x焊接接头系数，热膨胀系数，c-比热，ρ-母材密度）是一个恒值，但由于导叶是一个大而厚的工件，μ_xα/cρ不是一个恒值。本文通过对多个水轮机导叶堆焊的实验中，测定了导叶的纵向变形值。用数值解修正了μ_xα/cρ的值，并通过用ABAQUS软件的三维有限元分析验正了数值解，计算结果表明修正后的计算模型的变形误差在所要求的范围之内（纵向挠度误差＜5％）。这对怎样控制焊接变形提供了参考和理论依据。另外，在已知焊接参数、材料性能、水轮机转轮叶片几何形状的情况下，本文通过ABAQUS软件的三维有限元分析计算和预测了转浆式活动导叶堆焊时的纵向变形量，预测了叶片轴向变形的最大值与变形曲线，并成功预测了堆焊时的最佳焊接顺序，残余应力分布图，而且进行了焊接温度场的分析。最后在上述理论的指导下，提出了减小堆焊残余变形的许多措施，成功地把观测点最大纵向挠度控制在允许范围内（＜0.5mm）。更多还原

【Abstract】 Because the hydraulic turbine unsteady blades in HuangHe抯 upper Reaches water power station have been deteriorated by mud and sand, and destroyed by cavitation erosion for many years, their original designed form has been changed. When the electrode collar bead welding was used to repair of the hydraulic turbine blade, some degree winding can be found after the blade was welded, especially, vertical flexibility (~O.5nim) can抰 meet the needs of the water course perfonnance for the hydraulic turbine blade turning around. In this paper, the vertical deformation value was tested after several blades were welded. When the graphic analytic solution was applied to calculate the welding deformation, Lt a /c i (i~?s-welding coefficient, a -heat expansion coefficient)was assumed a fixed value. However, because the blade is a large and thick workpiece, t.~ , a /c p is not a fixed value. ~-?~ a Ic p was not only revised by numerical solution ,but analyzed by three dimensional finite element analysis of the ABAQUS software in this paper. The result shows that the deformation error of revised model is inside the scope of requirement(veitical flexibility error<5%).So it provides reference and theory basis for us to control welding deformation. Morefore,it is necessary to predict the welding deformation and determine the optimal sequence of welding by the computer in the course of the known parameters of welding ,performance of material and geometry of the blades. In this paper three dimensional finite element of the ABAQUS software is successfully applied to predict the maximal value and the curve of longitudinal flexibility , the distributing plot of stress and the optimal sequence of welding.更多还原