摘要
自保护药芯焊丝广泛应用在野外焊接及修复领域中,其中在野外薄壁管道的焊接中,减少母材热输入,保证焊接质量具有重要意义.因此探索了适用于野外薄壁管道焊接的细直径自保护药芯焊丝CMT技术,利用电信号采集系统和高速摄影系统,对比分析了不同极性下的熔滴过渡过程.结果表明,在不同极性下,熔滴过渡表现为混合过渡模式.在直流反接条件下,峰值阶段下的熔滴过渡模式主要表现为大滴排斥过渡.在直流正接条件下时,峰值阶段下的熔滴过渡模式主要表现为射滴过渡,相比于直流反接条件,焊缝的熔深较浅,余高较高,熔宽较宽.焊接参数的增大,并未改变熔滴过渡的模式.爆炸型焊接飞溅主要出现在直流正接条件下的短路阶段中.排斥型飞溅主要出现在直流反接条件下的峰值阶段中.创新点:(1)探索了不同电极极性条件下的熔滴过渡过程,针对不同电极极性下的熔滴过渡模式变化,主要分析解释了电极极性对熔滴过渡模式的影响机理.(2)对比不同极性下发生的飞溅过程,分别分析了电极极性对飞溅过程的影响以及飞溅产生的机理.
self-shielded flux cored wire is widely used in the field welding and repair.In the field thin-walled pipeline welding,it is of great significance to reduce the heat input of base metal and ensure the welding quality.Therefore,this paper explores the CMT technology of fine diameter selfshielded flux cored wire,which is suitable for thin-walled pipeline welding in the field.The results were shown that the droplet transfer was the mixed transfer mode under different polarity,the mainly mode was the short-circuit transfer.In DCEP(direct current electrode positive),in the stage of peak,the droplet transfer mode is mainly characterized by globular repelled transfer.In DCEN(direct current electrode negative),the droplet transfer mode is mainly projected transfer in the stage of peak.With the increase of welding parameters,the mixing droplet transfer mode has not been changed.At the same time,the explosive welding spatter mainly occurred in the short-circuit stage under DCEN.The exclusion spatter mainly appeared in the peak stage under DCEP.Highlights:(1)Explore the droplet transfer mechanism of self shielded flux cored wire under CMT.The electrode polarity determines the droplet transfer mode.(2)Analyze the weld bead characteristics of self shielded flux cored wire under CMT.Compared with DCEP,the bead in DCEN performed shallower penetration and lower reinforcement,but it can obtain wider penetration width.(3)Study the mechanism of welding spatter of self shielded flux cored wire under CMT.When in DCEN,the main spatter appears in the short circuit phase.When the DC connection is reversed,the repulsion of droplets becomes the main spatter in peak stage.
作者
张恒铭
石玗
李春凯
顾玉芬
朱明
ZHANG Hengming;SHI Yu;LI Chunkai;GU Yufen;ZHU Ming(Lanzhou University of Technology,Lanzhou,730050,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2021年第8期75-81,I0005,I0006,共9页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51905245)
国防科工局科研基础研究计划项目(JCKY2018427C001)
甘肃省引导科技创新发展专项资金项目(2019ZX—08)
甘肃省重点研发计划项目(20YF3WA017)
有色金属先进加工与再利用国家重点实验室资助项目(SKLAB02019009)
北京石油化工学院开放基金
浙江省自然科学基金(LQ21E050023)
甘肃省自然科学基金(20JR10RA164)
省部共建有色金属先进加工与再利用国家重点实验室开放课题(SKLAB02019009).
关键词
自保护药芯焊丝
CMT
熔滴过渡
焊接飞溅
self-shielded flux cored wire
CMT
droplet transfer
welding spatter
