Nb对690镍合金带极堆焊金属结晶裂纹的影响  

EFFECT OF NB ON WELDING SOLIDIFICATION CRACKING OF 690 NICKEL ALLOY SURFACING METAL

作　　者：薄春雨[1] 杨玉亭[1] 李向阳[1] 周世峰[1] 

机构地区：[1]机械科学研究院哈尔滨焊接研究所,150080

出　　处：《焊接》2006年第6期41-45,60,共6页Welding & Joining

摘　　要：采用横向可调拘束方法,研究了典型合金元素Nb对690镍合金带极堆焊金属结晶裂纹的影响。试验结果表明:随着Nb含量的增加,690堆焊金属的开裂临界应变量减小,最大裂纹长度增大,临界应变速率下降,结晶裂纹敏感性增大。金相分析表明,随Nb含量的增加,奥氏体晶界变宽,晶界富Nb第二相数量增多,在Nb含量大于2.0%的材料中,第二相的晶界偏聚甚至诱发了二次裂纹。The effect of Nb on solidification cracking resistance of 690 nickel alloy surfacing metal was researched by trans-varestraint test. When the content of Nb increases, the minimum cracking strain and the critical strain for temperature drop decreases, while the maximum cracking length increases. The results show that solidification cracking susceptibility increases when the content of Nb increases. Metallographic analysis and SEM results show that the width of austenite grain boundary and the quantity of precipitated Nb-rich phase increase with the content of Nb increasing. When the content of Nb increases to higher than 2.0%, the segregation of Nb in grain boundary even lead to a secondary cracking.

关 键 词：NB 690镍合金 结晶裂纹 横向可调拘束试验 

分 类 号：TG457.11[金属学及工艺—焊接] TG455