摘要
核电站钢制安全壳底封头是国内核电行业首次采用的大尺寸、厚壁、多曲率、高精度花瓣椭球形焊接结构,并在现场组装、焊接。专用设备按不同曲率半径压制成型的钢板自身存在较大的残余应力,四圈钢板数量各不相同,导致各圈焊接收缩变形有所不同,预留焊接收缩间隙等较难控制,增加了组装难度,影响钢制安全壳底封头整体尺寸的控制,因此适宜的组装方式和焊接变形控制成为施工过程中的重要环节。从三种堆型的钢制安全壳底封头的两种拼装方式、焊接顺序以及焊接防变形工装、焊接工艺措施等方面着手进行分析研究,明确了两种拼焊方式均为可行,同时提出了自上而下的拼装方式的改进方向。
Containment vessel bottom head (CVBH),assembled and welded on nuclear power project sites,is a petal-shaped ellipsoidal structure featured by large size,thick walls,multiple curvatures,and high precision,which is adopted by China's nuclear power industry for the first time. The steel plate formed by special equipment through compression molding on the basis of different radii of curvature has large residual stress. Besides,the number of steel plates constituting each ring is different. These characteristics lead to different welding shrinkage and deformation for each ring and make it difficult to reserve a proper welding shrinkage gap. All these increase the difficulty of the assembling and greatly affect the control of the overall dimensions of the CVBH. Therefore,suitable assembly methods and welding deformation control become an important part of the construction process. This paper studies the two types of assembly,welding sequence,anti-deformation welding fixtures,welding processes and other measures of CVBH in three types of nuclear power reactors. Through such introduction and analysis,this paper has validated that the two types of assembly are both feasible and proposed the direction of improvement for the top-down assembly method.
作者
王士林
刘中仁
赵秀运
WANG Shilin;LIU Zhongren;ZHAO Xiuyun(State Nuclear Power Engineering Co.,Ltd.,Shanghai 200233,China)
出处
《电焊机》
2019年第4期244-249,共6页
Electric Welding Machine
关键词
钢制安全壳
底封头
拼装
变形控制
steel containment
CVBH
assembly
deformation control
