拉筋形式对汽轮机隔板外环焊后变形的影响

The Influence of Reinforcing Type on Welding Distortion of Steam Turbine Diaphragms Shell

为解决汽轮机隔板外环堆焊后焊接变形大导致装配精度低以及物理试验成本高的问题,依据焊接温度场相似准则应用数值模拟技术建立有限元模型研究了焊拉筋对焊接变形的控制.设计了梁型和米字型两种拉筋形式,并对比了梁形拉筋和米字型拉筋控制焊接变形能力.通过模拟结果得到隔板外环焊后在轴向、周向和径向的变形规律以及拉筋后隔板外环焊后变形情况.通过模拟结果得到如下结论,米字型拉筋控制焊接变形的能力要优于梁型拉筋,隔板外环外圆三个方向的变形量都要大于内圆的变形量.

To solve the problem of large welding distortion which leads to the low assembly accuracy and the high cost physical test. Numerical simulation is used to study how the reinforcing controls the welding distortion by building the finite element model based on the similarity theory of welding temperature field. Two types of reinfor- cing are designed and contrasted the ability to control welding distortion. Through the simulation results, the distor- tion rules in three directions of diaphragms shell are known. The three directions are axial direction, radial direc- tion and circumference direction. The conclusion is that the ability to control welding distortion of type A is better than type B＇ s and the welding distortion of excircle is larger than incircle＇ s in three directions.