【作者】 吕一仕；

【导师】 荆洪阳；

【作者基本信息】 天津大学 ， 材料加工工程， 2012， 硕士

【摘要】 本课题以孟买地铁项目为背景,分析了不同的焊接工艺对地铁转向架侧梁焊接残余应力的影响,以及采用何种焊接顺序使得转向架侧梁的焊接变形最小等问题。考虑到经济因素和可操作性,本课题使用T型板来替代转向架侧梁作为研究对象,研究不同的焊接工艺对焊接残余应力的影响。通过红外热像仪测量了T型板在焊接过程中的温度场分布,获得T型板的焊接温度循环曲线,采用盲孔法测得T型板的焊接残余应力。实验完成后,采用有限元模拟计算加以验证。并且发现,TIG熔修能一定程度的降低焊缝中心的残余应力,但增大了熔修区域的残余应力;而通过整体热处理能有效地消除熔修带来的大部分残余应力。另外,实验获得的数据结果反过来验证了有限元计算方法的准确性。最后采用同样的有限元计算方法对地铁转向架侧梁进行模拟,得到了不同焊接顺序下侧梁焊接变形的具体数据,为工程实际工作提供了依据。更多还原

【Abstract】 Based on the program of Mumbai subway, the research analyzes the influence of different welding procedure on residual stress of side beam, and how to choose the welding sequence to make sure the deformation of the side beam is the smallest.Considering the economic factors and maneuverability, T-joint plates are used to replace the side beam in order to research the influence of different welding procedure on residual stress. The welding temperature field of T-joint plates was measured by using an infrared thermal imager, and the thermal cycles were experienced during welding were achieved; the residual stress of T-joint plates were measured by blind-hole method. After the experiment, the finite element method was used to verify the results. The results showed that the method of TIG remelting could limitedly Lower the residual stress in seam center area, but the residual stress in remelting area were increased. However, by the overall heat treatment much residual stress brought by TIG remelting could be eliminated effectively. In addition, the experimental results also verified the accuracy of the finite element method.At last, the same finite element method was used to simulate the welding process on the side beam of the subway; and the data about welding deformation of side beam welded by different welding sequence was acquired, which provide the basis for practical work.更多还原