弥散型腐蚀损伤管道剩余寿命预测方法

基于损伤理论,将管壁点腐蚀损伤层材料视作孔洞型均匀损伤材料,通过模拟多孔材料拉伸实验,研究了孔洞型损伤管线钢表观弹性模量和屈服强度退化规律.根据稀溶液理论,导出了腐蚀损伤沿壁厚方向的分布模型.通过腐蚀实验,研究了腐蚀损伤管线钢力学性能随时间的变化规律.根据腐蚀损伤规律,并结合相应的管道应力和强度分析,提出了一种新的点腐蚀弥散损伤管道剩余寿命的预测方法.

A method for predicting remaining life of pipeline with dispersion-type corrosion damage

The pitting corrosion damage of pipeline was considered as uniform hole-type damage based on the damage theory. The degradation regularity of apparent yield strength and elastic modulus of damaged pipeline steel was investigated by tension test of specimen with artificial holes. On the basis of diluted solution theory, a model for describing corrosion process of the harmful media within the pipeline and the corrosion damage distribution along the radial direction of the pipeline was derived. The variation regularity of the mechanical properties of corroded pipeline steel with time was studied by corrosion test. Combining the above damage rules with the corresponding variation analyses of stress states and strength, a new approach to predict the remaining life of pitting corrosion damaged pipeline was proposed.