稀土La_(2)O_(3)对CMT堆焊Inconel 625合金显微组织和抗高温氧化性能影响  

Effect of La_(2)O_(3) on Microstructure and High-temperature Oxidation Resistance of Inconel 625 Alloy by CMT Surfacing

作　　者：王晓玲 朱开阳 顾先锋 段君杰 杨克 邹晓东 李伟[4] 易江龙 WANG Xiao-ling;ZHU Kai-yang;GU Xian-feng;DUAN Jun-jie;YANG Ke;ZOU Xiao-dong;LI Wei;YI Jiang-long(Guoneng Fuquan Power Generation Co.,Ltd.,Guizhou Fuquan 550501,China;Pourin Special Welding Technology Co.,Ltd.,Guangdong Jiangmen 529728,China;China-Ukraine Institute of Welding,Guangdong Academy of Sciences,Guangzhou 510650,China;Beijing Jinwei Welding Materials Co.,Ltd.,Beijing 102200,China)

机构地区：[1]国能福泉发电有限公司,贵州福泉550501 [2]广东博盈特焊技术股份有限公司,广东江门529728 [3]广东省科学院中乌焊接研究所,广州510650 [4]北京金威焊材有限公司,北京102200

出　　处：《精密成形工程》2023年第7期190-199,共10页Journal of Netshape Forming Engineering

基　　金：广东省粤港澳大湾区国际科技创新中心建设项目(2022A0505050052);广东省基础与应用基础研究基金(2021A1515011756)。

摘　　要：目的研究稀土氧化物对CMT堆焊镍基合金显微组织和性能的影响规律。方法采用静电自组装工艺制备含有1%(质量分数,下同)La_(2)O_(3)的Inconel 625药芯焊丝,再采用CMT堆焊工艺制备Inconel 625和1%La_(2)O_(3)/Inconel 625镍基合金试样。系统研究添加La_(2)O_(3)对Inconel 625堆焊试样显微组织、显微硬度、拉伸强度及抗高温氧化性能的影响。结果添加了La_(2)O_(3)的Inconel 625堆焊试样的金相组织明显细化,且显微组织由柱状晶转变为等轴晶。基体组织主要为γ-Ni固溶体和少量Laves相,且添加了La_(2)O_(3)的镍基合金Laves相的尺寸更为粗大。随着稀土氧化物La_(2)O_(3)的添加,显微硬度值从(235.97±2.99)HV0.3增加到(246.53±4.10)HV0.3,抗拉强度从543.12 MPa增加到564.25 MPa。在高温氧化试验条件下,CMT堆焊1%La_(2)O_(3)/Inconel 625试样的氧化速率明显小于未添加La_(2)O_(3)的Inconel 625原始试样的氧化速率。结论稀土La_(2)O_(3)的添加产生了细晶强化以及柱状晶向等轴晶的转变,使Inconel 625堆焊试样的显微硬度和抗拉强度都有了一定的提升。在高温氧化过程中,稀土La_(2)O_(3)可作为Cr_(2)O_(3)氧化物的形核中心,促进致密Cr_(2)O_(3)氧化膜生长,相应提升了其表面的抗高温氧化性能。The work aims to study the effect of rare earth oxide on the microstructure evolution and properties of nickel-based alloy by CMT surfacing.First of all,the electrostatic self-assembly process was used to prepare 1wt.%La_(2)O_(3)/Inconel 625 flux-cored welding wire,and Inconel 625 and 1wt.%La_(2)O_(3)/Inconel 625 nickel-based alloy samples were manufactured by CMT surfacing process.The effects of microstructure,microhardness,tensile strength,and high-temperature oxidation resistance were systematically analyzed.The microstructure of Inconel 625 surfacing sample was refined after addition of La_(2)O_(3),changing from columnar crystal to equiaxed crystal.The matrix structure was mainly composed ofγ-Ni solid solution and a small amount of Laves phase,and the Laves phase size of nickel-based alloy with La_(2)O_(3) was larger.With the addition of La_(2)O_(3),the microhardness value increased from(235.97±2.99)HV0.3 to(246.53±4.10)HV0.3.The tensile strength increased from 543.12 MPa to 564.25 MPa.Under the high-temperature oxidation test conditions,the oxidation weight gain rate of CMT surfacing 1wt.%La_(2)O_(3)/Inconel 625 sample was significantly lower than that of the original Inconel 625 sample.The microhardness and tensile strength are improved to a certain extent based on the fine grain strengthening and the transformation from columnar crystal to equiaxed crystal caused by the addition of rare earth La_(2)O_(3).In the process of high-temperature oxidation,rare earth La_(2)O_(3) can also serve as the nucleation site of Cr_(2)O_(3) oxide,promote the growth of dense Cr_(2)O_(3) oxide film,and correspondingly improve the high-temperature oxidation resistance.

关 键 词：镍基高温涂层 增材制造 稀土氧化物 CMT 高温氧化 

分 类 号：TG455[金属学及工艺—焊接]