Al元素含量对22MnB5钢激光焊接接头组织与力学性能影响研究  

Research on the Effect of Al Content on Microstructure and Mechanical Properties of Laser Welded Joint of 22MnB5 Steel

作　　者：吴晨雨 刘海江[1] 汪乾 潘宣军[1] 张衡 Wu Chenyu;Liu Haijiang;Wang Qian;Pan Xuanjun;Zhang Heng(School of Mechanical Engineering Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学机械与能源工程学院,上海200092

出　　处：《应用激光》2024年第11期34-46,共13页Applied Laser

摘　　要：采用激光焊接工艺对22MnB5高强度钢分别进行深熔焊和热导焊试验,表面添加铝箔调控焊缝Al元素含量,研究Al元素含量对22MnB5钢接头显微组织与力学性能的影响。结果表明,随着焊缝中Al元素含量的增加,焊缝表面形貌的塌陷、咬边、气孔缺陷以及富Al焊渣会开始增多。焊接接头的微观组织主要由板条马氏体与α-铁素体所组成,在靠近镀层的上下焊趾处有弥散分布的富Al的IMCs,热导焊整体焊缝的Al元素均质化要优于深熔焊。焊缝显微硬度呈现焊缝中心硬度较高、焊缝边缘硬度较低的分布,α-铁素体随着Al元素含量的增加而增加,使焊缝显微硬度分布减小。深熔焊接头抗拉强度明显优于热导焊,尤其是在上表面镀Al层,焊缝Al含量为0.47%时,接头抗拉强度为1477 MPa。Laser welding was used to weld 22MnB5 high-strength steel in deep penetration welding and heat conduction welding.Aluminum foil was added on the surface to control the content of Al element in the welds,and the effects of Al content on the microstructure and mechanical properties of 22MnB5 steel welded joints was studied.Results showed that,in both deep penetration and heat conduction welding,an increase in Al content in the weld led to an increase in surface defects such as collapse,undercut,porosity and Al-rich weld slag.The microstructure of the welded joint mainly consisted of lath martensite andα-ferrite,with Al-rich intermetallic compounds(IMCs)disperse near the upper and lower weld toes close to the coating.The Al element homogenization in the weld was better in heat conduction welding compared to deep penetration welding.The microhardness of weld showed higher hardness in weld center and lower hardness at weld edge.With an increase in Al content,the density ofα-ferrite increased,then led to a reduction in microhardness.The tensile strength of both deep penetration welded joint were higher than the heat conduction welded joint,especially with Al coating on the upper surface.When the weld Al content is 0.47%,the tensile strength of welded joint is 1477 MPa.

关 键 词：22MnB5高强度钢 AL元素 激光焊接 接头组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]