腐蚀管道剩余寿命的性能衰减模型研究

Study on Performance Degeneration Model for Remaining Lifetime of Corroded Pipeline

管道在长期的运行过程中,由于介质和土壤的腐蚀性、管材的微塑性变形、结构转变和渗氢等,不仅会使管道出现各种腐蚀损伤,而且还存在着老化效应和氢化作用,导致管材的脆变并改变材料的塑性,使机械性质参数发生衰退。从管材性能衰减和腐蚀损伤角度研究了管道的剩余寿命,提出了根据结构承载能力的极限值确定塑性变形时工作寿命的方法。为了确定剩余使用寿命,对剪切损伤率和屈服性能比等概念进行定义,在掌握管材金属剪切损害率和屈服性能比的时间特性基础上,建立了剩余寿命计算模型,并给出了算例。

During operating chronically,because of corrosion of medium and soil, micro-plasticity deformation of pipe material, changing of structure and filtering of hydrogen, there are not only various cumulative damages, but also ageing and hydrating phenomenon in pipeline which maybe make pipe material brittle-ness and its mechanical performance attenuated. In this paper,the remaining lifetime of corroded pipeline is studied from material performance degeneration and cumulative damage. For this reason, the notions of shear damage rate and yield capability ratio are defined, and their characteristics on time are studied. A method of determining operation lifetime of pipeline is put forward on limited carrying capacity of structure and plasticity deformation. The models for calculating remaining lifetime are developed by defining of shear damage rate and yield capability ratio. Finally,an example is given.