含环向减薄缺陷主蒸汽管道蠕变应力变化规律研究  

Study on Variation Law of Creep Stress of Main Steam Pipe with Hoop Wall Thinning

作　　者：薛吉林[1] 周昌玉[1] 生建文[1] 贺小华[1] 

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京210009

出　　处：《压力容器》2010年第11期1-7,24,共8页Pressure Vessel Technology

基　　金：江苏省自然科学基金项目(BK2008373);江苏省普通高校研究生科研创新计划项目(CX10B_164Z)

摘　　要：厚壁耐热钢广泛应用于高温电厂的主蒸汽管道。局部减薄缺陷是高温压力管道常见的体积型缺陷,局部减薄缺陷的存在对高温环境下运行的管道应力重分布会产生较大的影响,降低管道的承载能力。采用大型有限元分析软件ABAQUS对在蠕变条件下运行、受内压作用含环向减薄缺陷主蒸汽管的蠕变应力进行了有限元数值模拟,获得了应力重分布的变化过程。结果表明,含环向减薄缺陷直管,由于存在结构不连续,导致应力水平提高。在高温环境下,应力最大位置和应力集中系数最大位置可能会随蠕变时间的变化而改变,给出了含环向减薄管道应该主要关注的位置。研究结果可为高温含环向减薄缺陷管道的安全评定和完整性分析提供依据。Thick wall heat -resistant steel pipes are widely used as main steam pipe at high temperature in power plants. The local wall thinning defect is a common defect in high temperature pressure pipes. The exist of local wall thinning may probably result in stress redistribution of the pipes and reduces the load carrying capability of the pipes at elevated temperature in service. Creep stress of main steam pipe with hoop wall thinning under internal pressure only was simulated by the finite element analysis codes ABAQUS. The results indicate that structure discontinuousness of the pipe with hoop wall thinning will raise the stress level. The position of maximum stress and maximum stress concentration factors may change with the creep time increase at high temperature. The most concerning points of pipes, with local wall thinning was given. The research results can provide the possibility on safety assessment and structure integrity analysis of the pipe with hoop wall thinning at high temperature effectively.

关 键 词：主蒸汽管 环向减薄 蠕变 应力集中 有限元 

分 类 号：TK223.1[动力工程及工程热物理—动力机械及工程] TB115[理学—数学]