发动机用K439B镍基高温合金光纤激光自熔焊性能分析  

Characterization of Laser Welded Joint of K439B Alloy: A Methodological Study

作　　者：门殿勇[1] 李刚[2] Men Dianyong;Li Gang(Department of Intelligent Manufacturing,Neijiang Vocational and Technical College,Neijiang 641000,China;College of Mechanical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]内江职业技术学院智能制造系,内江641000 [2]四川大学机械工程学院,成都610065

出　　处：《真空科学与技术学报》2020年第7期697-701,共5页Chinese Journal of Vacuum Science and Technology

基　　金：省级高技能人才培训基地建设项目NZ2018C07。

摘　　要：采用激光自熔焊方法连接K439B焊接头,开展焊接头组织结构转变并对其力学特性进行了测试,分析焊接速率对其焊缝微观组织及焊缝变形程度的影响。研究结果表明:随着焊接速率提高,K439B焊接头获得热输入低,靠近焊缝中心部以等轴晶为主柱状晶,基本都是出现在熔合线区域,形成更细的焊缝组织,并引起焊缝硬度的明显提升。随着焊接速率增加,K439B焊接头拉伸强度和伸长率均表现出先增加后减小,最大值发生在焊接速率4 m/min时,此时拉伸强度和伸长率分别为852 MPa和44.5%。对焊接速率4 m/min下K439B焊接头在焊缝内形成了连续分布的胞晶、柱状晶、等轴晶。K439B焊接头形成了平整的表面区域,存在许多韧窝结构,主要表现为穿晶断裂的特点,焊缝端部发生了明显变形。The joints of K439 B Ni-based supper-alloy,an advanced aircraft engine material,were welded with continuous wave(CW)laser in argon atmosphere.The influence of the welding-rate on the microstructures,deformation and tensile strength was investigated with scanning electron microscopy,X-ray diffraction and energy dispersive spectroscope.The results show that the welding-rate had a major impact.Generally speaking,a faster welding-rate,that is,a lower heat input,produced a narrower welding beam with stronger hardness,comprising equiaxed and columnar grains localized at welding center;as the welding-rate increased,the tensile-strength and elongation-ratio changed in an increase-decrease manner,maximizing at 4 m/min to 852 MPa and 44.5%,respectively.Welded at 4 m/min,the continuous distributions of cellular/equiaxed/columnar grains and quite a few dimples coexisted in the flat compact welded seam,with significant deformation localized at the joints’ends.Shear and cleavage fractures account for the fracture mechanism.

关 键 词：K439B焊接头 激光焊接 显微组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]