纯镍与304不锈钢激光异种焊接的工艺及其接头的组织性能  

Laser dissimilar welding process of pure nickel and 304 stainless steel and microstructure and properties of welded joint

作　　者：夏纯阳 虞钢[1,2] 何秀丽[1] 李少霞[1] 宁伟健[1] 苗海宾 XIA Chun-yang YU Gang HE Xiu-li LI Shao-xia NING Wei-jian MIAO Hai-bin(Key Laboratory of Mechanics in Advanced Manufacturing, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院力学研究所,北京100190 [2]中国科学院大学工程科学学院,北京100049

出　　处：《材料热处理学报》2017年第7期87-92,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(11272317;11502269)

摘　　要：采用高密度Nd:YAG固态连续激光器对N6纯镍和304奥氏体不锈钢进行了焊接工艺实验,探究了激光功率和离焦量对焊缝成形的影响。对接头进行了拉伸强度和硬度的测试,并结合光学显微镜(OM)、扫描电镜(SEM)、能谱分析仪(EDS)等手段分析了接头的微观组织。结果表明:N6纯镍一侧热影响区晶粒长大明显,焊缝区靠近两侧熔合线附近为向焊缝中心区域生长的柱状晶,焊缝中心区域存在细小的胞晶区域;N6热影响区的显微硬度最低,焊缝的显微硬度介于N6镍母材和304不锈钢母材之间;接头拉伸断裂位置在焊缝区,抗拉强度达到N6纯镍母材的90%以上,可以满足实际情况下的使用要求。拉伸断口表现为准解理断裂。The welding experiment of N6 pure nickel and 304 austenitic stainless steel was carried out by using high density Nd：YAG solid-state laser, and effects of laser power and defocusing distance on the weld seam formation were investigated. The microstructure and fracture morphology of the welded joint were analyzed by means of OM, SEM and EDS analysis, and the mierohardness and tensile strength of the welded joint were tested. The results show that the grain growth in the heat affect zone（HAZ） of nickel N6 side is obviously due to overheating. The microstructure in weld seam near fusion line is columnar crystal while in central area of the seam is cellular crystal. In addition, the minimum of Vickers-hardness is found in the HAZ of nickel N6. The tensile fracture position of the welded joint is in the weld zone, and the tensile strength of the welded joint is more than 90% that of the nickel N6 base metal. The fractographs of the welded joint show that the tensile fracture is quasi-cleavage fracture.

关 键 词：纯镍 304不锈钢 激光异种焊接 组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]