Inconel625高温合金等离子弧加丝焊接接头组织与性能  

Microstructure and Properties of Inconel625 Superalloy Plasma Welded Joints with Filler Metal

作　　者：张忠科[1] 胡炜皓 雍春军 ZHANG Zhongke;HU Weihao;YONG Chunjun(School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;PetroChina Lanzhou Petrochemical Company,Lanzhou 730060,China)

机构地区：[1]兰州理工大学材料科学与工程学院,兰州730050 [2]中国石油兰州石化公司,兰州730060

出　　处：《有色金属工程》2023年第9期23-32,共10页Nonferrous Metals Engineering

基　　金：甘肃省科技重大专项(18ZD2GC013)。

摘　　要：针对传统方法焊接厚板Inconel625合金时存在的未熔透、性能差的问题,采用等离子焊接技术对8 mm厚Inconel625合金进行焊接,同时采用ERNiCrMo-3焊丝作为填充材料保证成型。通过光学显微镜(OM)、扫描电子显微镜(SEM)、万能试验机和显微硬度试验机等设备对焊接接头进行显微组织和性能分析。结果表明,在焊接电流为230 A、焊接速度240 mm/min、送丝速度1400 mm/min、等离子气流量4 L/min下所获得焊接接头成型最好,力学性能最好;焊接接头均呈现出上宽下窄的“Y”字型形貌,母材区为奥氏体等轴晶,焊缝区基本以细小的胞状晶为主,熔合线区域为垂直于熔合线生长的粗大胞状晶,MC型碳化物和Laves相会在焊接过程中析出;接头抗拉强度最高,可以达到811.36 MPa,焊接接头断裂为韧性断裂;所有参数下焊接接头均是焊缝区硬度最高,随着焊接热输入的增大,焊接接头整体硬度值升高,当电流达到240与250 A时,焊接接头硬度差别较小。In view of the problems of incomplete penetration and poor performance in the traditional method of welding thick plate Inconel625 alloy,plasma welding technology was used to weld 8 mm thick Inconel625 alloy,and ERNiCrMo-3 welding wire was used as the filling material to ensure molding.The microstructure and properties of the welded joints were analyzed via Optical Microscope(OM),Scanning Electron Microscope(SEM),universal testing machine and microhardness testing machine.The results show that the welded joint has the optimal forming and mechanical properties under the welding current of 230 A,welding speed of 240 mm/min,wire feeding speed of 1400 mm/min and plasma gas flow of 4 L/min.The welded joints show a‘Y’-shaped morphology with a wide top and a narrow bottom.The base metal area is austenite equiaxed crystal,the weld zone is mainly composed of fine cellular crystals,and the fusion line area is coarse cellular crystals grown perpendicular to the fusion line,MC carbide and Laves phase will precipitate during the welding process.The tensile strength of the joint is the highest,which can reach 811.36 MPa,and the fracture of the welded joint is ductile fracture.The hardness of the weld zone is the highest under all parameters.As the welding heat input increases,the overall hardness of the welded joint increases.When the current reaches 240 A and 250 A,the hardness difference of the welded joint is small.

关 键 词：Inconel625 等离子焊接 微观组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]