GH600高温合金重熔层组织结构对激光焊接性能的影响研究  

Effect of Remelted Layer Microstructure of GH600 Superalloy on Properties of Laser Welding

作　　者：张超[1] 张亚光 米天健 郝娟[2] 姚特力 刁金香[1] 吴冬[1] ZHANG Chao;ZHANG Ya-guang;MI Tian-jian;HAO Juan;YAO Te-li;DIAO Jin-xiang;WU Dong(Department of Aeronautical Engineering,Xi'an Aeronautical Polytechnic Institute,Xi'an 710089,China;School of Materials Science and Engineering,Xi'an University of Technology,Xi'an 710048,China)

机构地区：[1]西安航空职业技术学院航空材料工程学院,西安710089 [2]西安理工大学材料科学与工程学院,西安710048

出　　处：《精密成形工程》2023年第8期148-155,共8页Journal of Netshape Forming Engineering

基　　金：陕西省自然科学基金(2021JQ-889);陕西省教育厅基金(21JP057)。

摘　　要：目的研究GH600高温合金重熔层组织对T形激光焊接强度的影响。方法采用激光焊工艺制备GH600高温合金T形焊接接头,采用金相显微镜、扫描电子显微镜和能谱仪观察重熔层去除前后焊接接头的显微组织和元素分布。采用电子万能试验机测试去除重熔层前后焊接接头的力学性能,采用维氏硬度计测试焊接接头的硬度。结果去除重熔层的焊接接头的抗拉强度约为1400MPa,约为未去除重熔层焊接接头抗拉强度的3倍。结论焊接强度下降的主要原因如下:重熔层内部存在较大的内应力和缺陷;二次结晶时内应力释放;第二相对晶界的钉扎失效使晶粒异常长大,进而形成白带层。The work aims to study the effect of remelted layer microstructure of GH600 superalloy on the strength of T-shaped laser welding.A T-shaped welded joint of GH600 superalloy was prepared by laser welding.The microstructure and element distribution of the welded joint was observed with a metallographic microscope,a scanning electron microscope and energy disperse spectroscopy.The mechanical properties of the welded joint before and after the removal of the remelted layer were tested with an electronic universal testing machine.The microhardness of the welded joint was tested with a Vickers hardness tester.The results showed that the tensile strength of the welded joint with the remelted layer removed was about three times that of the welded joint without the remelted layer removed,which was about 1400 MPa.It can be concluded that the main mechanism that affects the decrease of welding strength is that there are large internal stress and defects inside the remelted layer.Meanwhile,the internal stress release during secondary crystallization and the pinning failure of the second phase grain boundary that cause the abnormal growth of grain and the formation of leucorrhea layer are also the important reasons for the decrease of welding strength.

关 键 词：重熔层 激光焊接 T形焊接接头 GH600高温合金 焊接强度 

分 类 号：TG454[金属学及工艺—焊接]