管壳式换热器内孔焊接残余应力特性研究

Study on Welding Residual Stress Characteristics of Inner Hole on Shell and Tube Heat Exchanger

常规焊接会使管壳式换热器的换热管与管板之间形成一定的缝隙.换热器长期处于腐蚀性介质环境中,因此易产生缝隙腐蚀和应力腐蚀开裂,通过内孔焊接的方式可有效降低这类腐蚀风险.以Q245材料为研究对象,利用ABAQUS软件对焊接过程中温度场、应力场进行了模拟,研究了管壳式换热器内孔焊接的残余应力分布、设备变形情况,以及不同内孔焊结构残余应力和变形程度的差异,总结了焊接工艺参数对深孔焊接残余应力的影响规律.研究结果表明:全对接型接头的应力集中范围更小,设备应力分布更均匀、变形量较小,焊缝质量较高、承载能力较强.

Conventional welding would make a certain gap between the tube and tube plate of shell and tube heat exchanger.The heat exchanger was in the corrosive medium environment for a long time,so it was easy to produce crevice corrosion and stress corrosion cracking.The inner hole welding could effectively reduce the risk of such corrosion.The residual stress distribution and equipment deformation of the inner hole welding on shell and tube heat exchangers were studied,and the differences of the residual stress and deformation degree of different inner hole welding structures were studied.The influence of welding process parameters on deep hole welding residual stress was summarized.The research results showed that the stress concentration range of the full butt joint was smaller,the stress distribution of the equipment was more uniform,the deformation was smaller,the quality of the weld was higher,and the bearing capacity was stronger.