45钢特厚复合坯真空电子束焊接头裂纹倾向分析  

Analysis of Crack Tendency in Vacuum Electron Beam Welding Joints of 45 Steel Ultra-thick Composite Billets

作　　者：蒋健博 厉文墨 刘芳芳 江坤 付魁军 JIANG Jianbo;LI Wenmo;LIU Fangfang;JIANG Kun;FU Kuijun(State Key Laboratory of Metal Material for Marine Equipment and Application,Anshan 114009,China;Ansteel Beijing Research Institute,Beijing 102209,China)

机构地区：[1]海洋装备用金属材料及其应用国家重点实验室,辽宁鞍山114009 [2]鞍钢集团北京研究院有限公司,北京102209

出　　处：《电焊机》2024年第2期64-69,共6页Electric Welding Machine

摘　　要：采用真空电子束焊接方法封焊并制备45钢特厚复合坯,通过金相显微镜(OM)、扫描电子显微镜(SEM)、维氏硬度计、冲击试验机等设备,分别分析了45钢复合坯封焊过程中不同位置(1#起弧处、2#中部、3#收弧处)接头组织与力学性能。结果表明,焊接位置由起弧处向收弧处变化时,接头熔深几乎不变,热影响区域面积逐渐减小。1#接头焊后冷却速度相对较慢,焊缝根部无裂纹产生,组织为针状马氏体与团块状托氏体混合物,硬度为588 HV,焊缝根部冲击性能为25.7 J,断口呈韧性断裂;2#及3#试样焊后冷却速度快,焊缝根部产生明显的穿晶裂纹,组织均为针状马氏体,随着焊后冷却速度的加快,马氏体数量增多尺寸变细;硬度分别升高至674 HV与729 HV,冲击性能下降,分别为18 J与13.7 J,并呈脆性断裂。The 45 steel composite billet was sealed and fabricated by vacuum electron beam welding method.The microstructure and mechanical properties of the electron beam joint at different positions(1#arc,2#middle and 3#arc closure)were analyzed by means of metallography microscope(OM),scanning electron microscope(SEM),Vickers hardness tester and impact testing machine.The results show that:When the welding position changes from the arc starting point to the arc retracting point,the joint penetration depth is almost constant,and the heat affected area decreases gradually.After welding,the cooling rate of the 1#joint is relatively slow,no crack occurs at the root of the weld,the structure is a mixture of acicular martensite and clumpy trotensite,the hardness(HV)is 588,the impact energy of the weld root is 25.7J,and the fracture is ductile.After welding,the cooling rate of the 2#and 3#samples is high,and obvious transgranular cracks appear at the root of the weld,and the microstructure is acicular martensite.With the acceleration of the cooling rate after welding,the number of martensite increases and the size becomes finer.The hardness(HV)increased to 674 and 729,respectively,and the impact property decreased to 18J and 13.7J,respectively,and showed a brittle fracture.

关 键 词：45钢复合坯 真空电子束焊接 接头组织 硬度 裂纹 

分 类 号：TG457[金属学及工艺—焊接]