稀释率对ENiCrFe-7焊材熔敷金属隔离层中凝固裂纹的影响机理  

Effect mechanism of dilution on solidification crack in ENiCrFe-7 buffering layer of deposited metal

作　　者：闫英杰[1] 张凯嘉 王若蒙 蒋勇[2] 曹睿[1] 陈剑虹[1] YAN Yingjie;ZHANG Kaijia;WANG Ruomeng;JIANG Yong;CAO Rui;CHEN Jianhong(The State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou,730050,China;Atlantic China Welding Consumables,INC.,Zigong,643000,China)

机构地区：[1]兰州理工大学,有色金属先进加工与再利用省部共建国家重点实验室,兰州730050 [2]四川大西洋焊接材料股份有限公司,自贡643000

出　　处：《焊接学报》2020年第7期12-17,I0001,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51961024,51761027)。

摘　　要：采用ENiCrFe-7镍基焊材作为填充金属对Q345B钢进行焊接,在熔敷金属的隔离层中发现存在较大尺寸的微裂纹.通过光学显微镜、扫描电子显微镜及能谱仪等手段,对隔离层内裂纹的分布、形态及裂纹内析出相等进行分析,并与不存在裂纹的熔敷金属区域进行对比.结果表明,裂纹只存在于隔离层中,该区域中的稀释率较高,导致Fe含量较高;隔离层中富Nb析出物数量高于无裂纹的熔覆金属区域;裂纹表面呈现出典型的凝固裂纹形态,并存在大量富集Nb,S元素的析出相;焊接过程中,富Nb,S低熔点相析出是导致隔离层中形成凝固裂纹的主要原因.Larger size microcracks were found in the buffering layer when ENiCrFe-7 nickel-based welding material is used as filler metal to weld Q345B steel.Adopting optical microscope,scanning electron microscope and energy spectrometer were used to analyse the distribution,morphology,and precipitation of cracks and compared results with the the area where no crack occurs.The results show that cracks are only distributed in the buffering layer which adjacent to the base material,and the dilution rate,Fe content,and number of Nb-rich precipitates in the crack occurrence area are higher than those in the area where no crack occurs;The crack is typical solidification crack and precipitation phases rich in Nb and S elements exist on the crack surface;The low melting point phase rich in Nb and S is the main cause of solidification cracking of buffering layer.

关 键 词：690焊材 隔离层 凝固裂纹 稀释率 析出相 

分 类 号：TG421[金属学及工艺—焊接]