Nb对690镍基合金焊条熔敷金属组织与性能的影响  

Influence of Nb on microstructure and mechanical properties of ENi Cr Fe-7 weld metal of 690 Ni-based alloy welding rod

作　　者：袁浩[1,2] 马成勇[2] 李莉[1] 齐彦昌[2] 詹肇麟[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,云南昆明650093 [2]钢铁研究总院先进钢铁流程及材料国家重点实验室,北京100081

出　　处：《金属热处理》2017年第2期16-21,共6页Heat Treatment of Metals

基　　金：国家高技术研究发展计划(863计划)(2007AA03Z506)

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)观察以及相图计算、拉伸试验、硬度试验,分析了Nb对三组690镍基合金焊条熔敷金属组织与性能的影响。结果表明:熔敷金属中的Nb以碳化物MC(M=Nb,Ti)相的形式析出。随着Nb含量的增加,熔敷金属中奥氏体晶粒的长大受到抑制,晶粒变细,晶界面积增大;随着Nb含量的增加,熔敷金属中的MC析出相增加,M_(23)C_6(M=Cr,Fe)析出相减少,晶界变得更加曲折,高温低塑性裂纹敏感性降低;随着Nb含量的增加,熔敷金属的硬度值和塑性提高。Influence of Nb on microstructure and mechanical properties of Ni-based weld metal was analyzed by using optical microscopy and scanning electron microscopy techniques,the calculation of the equilibrium phase fractions,tensile test and hardness test. The results show that the weld metals were dominant with dendrites and interdendritic phases,（ Nb,Ti） Cs were the main precipitate phases. The addition of Nb in the weld metal could inhabit the grain growth,refine grain and increase the area of grain boundary; Adding Nb can fix C and form MC（ M = Nb,Ti） precipitates,which were present to＂pin＂grain boundary motion and make boundary more tortuous,reduce number of M（23）C6（ M = Cr,Fe） and sensibility of ductility dip cracking（ DDC）; The addition of Nb can improve the tensile plasticity and hardness of the weld metals.

关 键 词：镍基合金焊条 熔敷金属 NB 析出相 力学性能 

分 类 号：TG422.1[金属学及工艺—焊接]