摘要
为了研究线能量对铝钢异种金属双光束激光焊接接头组织和性能的影响,本工作通过激光双光束铝钢搭接焊工艺优化实验,获取了焊接工艺窗口,研究了焊接线能量与焊缝成形、显微组织和接头性能的关系。结果表明:不同焊接速度下,线能量过大或过小将导致焊缝出现坑洞或未连接,焊接速度超过0.05 m/s时,线能量的最高值和最低值基本维持不变,且线能量与熔深成正比,与熔宽无相关性。低线能量的焊接接头的抗剪切力为130.70 N/mm,断裂位置位于铝合金焊缝,而高线能量的焊接接头的抗剪切力仅有35.76 N/mm,断裂位置位于铝钢界面焊缝。低线能量接头的显微组织为板条马氏体,显微硬度的最高和最低值分别位于热影响区和焊缝中心,而高线能量接头的显微组织为粗大柱状晶或片状马氏体,显微硬度的最低值位于熔合区。在低线能量和高线能量接头处,主、辅助光束共同作用面积分别占整个焊缝截面积的1/3和2/3。
In order to research the connections between linear heat input and dissimlar metals welding of Al/steel,the relationships between linear heat input and welding formation,microstructure,joint performance have been researched according to the process window acquired by optimiza-ting experiments made use of dual-beam laser.The results show that inappropriate linear heat input will result in pothole on weld surface or invalid jointing,while both laser power are few alteration when the welding velocity surpass 0.05 m/s.Linear heat input is directly proportional to penetration,but has no correlation with melting width.The fracture location of linear low heat input joint is at the interface of alumnium and dual-phase steel with shear strength of 130.70 N/mm.While the fracture of high linear heat input joint emerges in alumnium weld with the shear strength of 35.76 N/mm.The microstructure at low linear heat input is consists of lath martensite,and lowest and highest micro-hardness are found in the center of weld and HAZ respectively,but for high linear heat input joint,the microstructure is make up of martensite with coarse columnar crystals and flakes,and the lowest micro-hardness zone of high linear heat input joint is appear in fusion line.The area effectted by main and auxiliary beams occupies two in three of weld area at high linear heat input,which bigger than that area at low linear heat input.
作者
韩善果
杨永强
罗子艺
蔡得涛
郑世达
HAN Shanguo;YANG Yongqiang;LUO Ziyi;CAI Detao;ZHENG Shida(School of Mechanical&Automotive Engineering,South China University of Technology,Guangzhou 510641,China;Guangdong Provincial Key Laboratory of Modern Welding Technology,Guangdong Welding Institute,Guangzhou 510650,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第2期2109-2114,共6页
Materials Reports
基金
广东省科学院项目(2017GDASCX-0411,2019GDASYL-0501011,2018GDASCX-0803)
广东省科技计划项目(2019A050508006,2018A050506058)。
关键词
双光束焊接
焊缝成形
接头性能
显微组织
线能量
dual-beam welding
welding formation
joint performance
microstructure
linear heat input
