不同工艺参数MIG焊Inconel 625熔覆层微观组织研究  

Study on Microstructure of Inconel 625 Cladding Layer by MIG Welding with Different Process Parameters

作　　者：马克 程龙 李继红[1] 毛威 刘智博 王森淼 MA Ke;CHENG Long;LI Jihong;MAO Wei;LIU Zhibo;WANG Senmiao(Xi'an University of Technology,School of Materials Science and Engineering,Xi'an 710048,China)

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《焊管》2024年第2期50-56,共7页Welded Pipe and Tube

基　　金：陕西省重点研发计划(秦创原“科学家+工程师”队伍建设项目)“航空航天用高品质钛基钎料的设计开发与应用”(项目编号2023KXJ-234);西安市科技计划项目(秦创原“科学家+工程师”队伍建设项目)“重点装备用高性能稀贵金属膏状钎料的设计开发及工程化”(项目编号23KGDW0004-2022)。

摘　　要：为了提高Q345钢的使用性能,采用商用Inconel 625实心焊丝以MIG沉积方法制备了镍基熔覆层,随后进行了OM、SEM、EDS、XRD分析和显微硬度测试试验,研究了熔覆层的微观组织、元素分布、不同焊接电流的稀释率、物相组成和表面硬度等。结果表明,采用MIG沉积方法制备的镍基熔覆层与基体结合良好,熔覆层无明显的宏观缺陷;熔覆层从顶部到底部依次产生等轴晶、柱状晶和胞状晶;熔覆层主要由单一的面心立方(fcc)结构γ-Ni固溶体相组成,由于熔覆层存在微观偏析,晶间Nb、Mo等元素浓度较高;随着焊接电流的增大,熔覆层稀释率逐渐变大,熔覆层底部柱状晶受热长大,平均硬度及沿熔覆层截面深度方向硬度均逐渐下降。In order to improve the performance of traditional steel material Q345,the nickel-based cladding layer was prepared by MIG deposition method with commercial Inconel 625 solid core welding wire.The microstructure,element distribution,dilution rate of different welding currents,phase composition and surface hardness of the cladding layer were studied by OM,SEM,EDS,XRD and microhardness test.The results show that the nickel-based cladding layer prepared by MIG deposition method has good bonding with the substrate,and the cladding layer has no obvious macroscopic defects.The cladding layer produces equiaxed crystals,columnar crystals,and cellular crystals from the top to the bottom.The cladding layer is mainly composed of a single face-centered cubic(fcc)γ-Ni solid solution phase.Due to the microsegregation of the cladding layer,the intergranular concentration of Nb,Mo and other elements is high.With the increase of welding current,the dilution rate of the cladding layer gradually increases,the columnar crystal at the bottom of the cladding layer grows up by heat,and the average hardness and the hardness in the depth direction of the cross section of the cladding layer gradually decrease.

关 键 词：MIG堆焊 Q345钢 镍基熔覆层 微观组织 硬度 

分 类 号：TG113.263[金属学及工艺—物理冶金]