镍基高温合金激光熔覆涂层组织及性能研究  

Study on microstructure and properties of laser cladding coating for base superalloy

作　　者：陈子豪 孙文磊[1] 黄勇[1,2] 崔权维 CHEN Zihao;SUN Wenlei;HUANG Yong;CUI Quanwei(School of Mechanical Engineering, Xinjiang University, Urumqi 830047, China;Mechanical and Electrical Engineering College, Xinjiang Engineering College, Urumchi 830023, China)

机构地区：[1]新疆大学机械工程学院,乌鲁木齐830047 [2]新疆工程学院机电工程学院,乌鲁木齐830023

出　　处：《激光技术》2021年第4期441-447,共7页Laser Technology

基　　金：新疆维吾尔自治区克拉玛依市科技重大专项资助项目(2018ZD002B);新疆维吾尔自治区高校科研计划资助项目(XJEDU2019Y064)。

摘　　要：为了研究高温合金激光熔覆涂层组织演变及力学性能,采用激光熔覆技术在2Cr25Ni20耐热奥氏体不锈钢表面制备镍基NiCrFeMo高温合金涂层。使用扫描电子显微镜、X射线衍射仪、能量色散光谱仪、显微硬度计等微观分析测试手段对该镍基高温合金涂层的微观组织形貌、物相种类、界面元素分布与偏析、各区域的硬度进行分析。结果表明,基材与熔覆层结合位置至熔覆层顶部,依次由多种晶粒形态生成;Nb与Mo元素在熔池金属液体对流作用下向基材发生扩散,其它元素基本无扩散;熔覆层存在物相有γ-Ni和Cr_(2)Fe_(14)C,熔覆层结合位置包含物相Fe_(2)Ni_(3),γ-(Fe,Ni)和Ni_(0.9)Nb_(0.1);基材显微硬度平均值为252HV_(0.3)左右,熔覆层显微硬度平均值为285HV_(0.3)左右;经常温拉伸试验,与2Cr25Ni20钢力学性能比较,2Cr25Ni20钢修复件抗拉强度升高,强度增大,断后伸长率明显下降,塑性降低。此研究为后续钢炉转轴修复提供了可行性方案。In order to study the microstructure evolution and mechanical properties of laser cladding coatings of high temperature alloy,a nickel-based NiCrFeMo high temperature alloy coating was prepared on the surface of 2Cr25Ni20 heat-resistant austenitic stainless steel using laser cladding technology.The cladding technology prepares a nickel-based NiCrFeMo high-temperature alloy coating on the surface of 2Cr25Ni20 heat-resistant austenitic stainless steel.Scanming electron microscope,X-ray diffraction,energy dispersive spectrometer,micro-hardness tester and other micro-analysis test methods were used to analyze the microstructure morphology,phase types,interface element distribution and segregation,and hardness of each area of the nickel-based superalloy coating.The results show that the bonding position of the base material and the cladding layer to the top of the cladding layer is sequentially generated from a variety of crystal grain morphologies.The Nb and Mo elements diffuse to the substrate under the action of the molten metal liquid convection,and the other elements basically have no diffusion.The cladding layer has phases:γ-Ni and Cr_(2)Fe_(14)C,while the bonding position of the cladding layer contains phases:Fe_(2)Ni_(3),γ-(Fe,Ni),and Ni_(0.9)Nb_(0.1).The average microhardness of the substrate is about 252HV_(0.3),and the average microhardness of the cladding layer is about 285HV_(0.3).In normal temperature tensile test,compared with the mechanical properties of 2Cr25Ni20 steel,the tensile strength of 2Cr25Ni20 steel repaired parts increases,the strength increases,the elongation after fracture decreases significantly,and the plasticity decreases.Therefore,this study provides a feasible plan for the subsequent repair of the steel furnace shaft.

关 键 词：激光技术 激光金属沉积 组织演变 力学性能 NI基高温合金 

分 类 号：TN249[电子电信—物理电子学] TG156.99[金属学及工艺—热处理]