Inconel 600镍基合金PAW+TIG接头微观组织及力学性能  

Microstructure and mechanical properties of Inconel 600 nickel-based alloy PAW+TIG joints

作　　者：乔小丽 曹帅[2] 武靖伟 张建晓 黄健康[2] 樊丁[2] QIAO Xiaoli;CAO Shuai;WU Jingwei;ZHANG Jianxiao;HUANG Jiankang;FAN Ding(Lanzhou LS Heavy Equipment Co.,Ltd.,Lanzhou,730314,China;State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of technology,Lanzhou,730050,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou,730000,China)

机构地区：[1]兰州兰石重型装备股份有限公司,兰州730314 [2]兰州理工大学,省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [3]中国科学院兰州化学物理研究所,固体润滑国家重点实验室,兰州730000

出　　处：《焊接学报》2024年第6期105-112,共8页Transactions of The China Welding Institution

基　　金：甘肃省科技重大专项资助项目(22ZD6GA008);甘肃省科技重点研发计划(20YF3GA041)。

摘　　要：针对Inconel 600镍基合金在石化装备行业的应用焊接问题,选择合适的焊接工艺是其所面临的一项挑战.采用PAW+TIG工艺流程对厚度为6 mm的Inconel 600镍基合金进行焊接,应用光学显微镜、扫描电镜和拉伸试验机等对Inconel 600镍基合金PAW+TIG接头的微观组织及其性能进行研究.微观组织分析结果表明,接头焊缝表面成形光滑平齐,半椭圆状的鱼鳞纹均匀分布,接头母材区域和热影响区的组织均为细小的等轴晶奥氏体,其中热影响区晶粒的尺寸大于母材区,焊缝区域的组织为树枝晶;接头的抗拉强度达到589 MPa,接头断裂类型为韧性断裂,焊接接头具有良好的塑性和抗弯曲性能;焊缝处电化学腐蚀测试结果表明,在焊接热影响区域局部腐蚀敏感性增加,说明焊接接头的耐腐蚀性降低;对焊缝退火处理并进行性能测试的结果表明,退火后焊接接头析出针状第二相,其在晶界和孪晶界处形成了一定的强化效应,能够抑制晶粒长大并影响材料的整体性能.综合分析焊接接头微观组织及其性能表明,采用PAW+TIG的接头热稳定性较好,能够满足其在高温条件下的工作要求.Addressing the welding challenges of Inconel 600 nickel-based alloy in the petrochemical equipment industry,selecting an appropriate welding process is challenging.A 6 mm thick Inconel 600 nickel-based alloy is welded using the PAW+TIG process.The microstructure and mechanical properties of the Inconel 600 nickel-based alloy PAW+TIG joints are studied using optical microscopy,scanning electron microscopy,and tensile testing machine.Microstructure analysis shows that the joint weld surface is smooth and even,with a semi-elliptical fish scale pattern uniformly distributed.Both the base material area and the heataffected zone exhibit fine equiaxed austenite crystals,with the grain size in the heat-affected zone being larger than in the base material area.The weld zone has a dendritic structure.The tensile strength of the joint reaches 589 MPa,and the fracture type is ductile,indicating good plasticity and bending resistance of the welded joint.Electrochemical corrosion tests at the weld indicate increased localized corrosion sensitivity in the heat-affected zone,suggesting reduced corrosion resistance of the welded joint.Post-weld annealing and performance testing shows that annealing precipitated needle-like second phases,forming a certain strengthening effect at grain boundaries and twin boundaries,which can inhibit grain growth and affect the overall performance of the material.A comprehensive analysis of the microstructure and performance of the welded joints shows that the PAW+TIG joints have good thermal stability,meeting the requirements for high-temperature operation.

关 键 词：镍基合金 PAW+TIG 微观组织 力学性能 退火 

分 类 号：TG442[金属学及工艺—焊接]