无钴马氏体时效钢电子束焊接接头组织与性能分析  

Microstructure and properties of electron beam welded joints of 18 Ni Co-free maraging steel

作　　者：莫德锋[1] 何国求[1] 胡正飞[1] 施延龄 张卫华[3] 

机构地区：[1]同济大学材料科学与工程学院,上海200092 [2]航天二院210所,陕西西安710065 [3]西南交通大学牵引动力国家重点实验室,四川成都610031

出　　处：《焊接学报》2008年第4期29-32,114,共5页Transactions of The China Welding Institution

基　　金：国家973基金资助项目(2007CB714705);国家自然科学基金资助项目(50771073)

摘　　要：对18Ni无Co马氏体时效钢进行了真空电子束焊接,用金相显微镜观察了焊接接头的组织形貌,并测定了焊缝区、热影响区、基体的显微硬度。结果表明,18Ni无Co马氏体时效钢组织为板条马氏体组织,材料焊接性能良好,焊缝区凝固组织为胞状树枝晶,熔合线附近热影响区晶粒发生了再结晶,晶粒长大明显。硬度分布有明显的规律性,焊缝区硬度最低,细晶区硬度最高,熔合线附近的热影响区,离熔合线越远,硬度值越高。在距熔合线2.5 mm处有一个马氏体与奥氏体两相混合的狭窄区域,硬度较其两侧有明显降低。Electron beam welding was used to weld 18 Ni Co-free maraging steels.The microstructure of welded joints was investigated by optical microscopy,and the microhardness of weld metal,heat-affected zone and base material was tested.The results show that the microstructure of the base materials is lath martensite,and the microstructure of weld metal exhibits a typical cystiform-dendritic morphology.The region adjoining the weld metal was heated to high temperatures in the austenite phase before rapid cooling.EB ...

关 键 词：无Co马氏体时效钢 电子束焊接 微观组织 硬度 

分 类 号：TG407[金属学及工艺—焊接]