表面自然腐蚀后带缺陷管钢的力学性能研究

针对腐蚀对管道钢的力学性能的影响问题，对不同腐蚀程度的管道钢进行拉伸试验，研究不同腐蚀程度的管道钢其力学性能与腐蚀损失度之间的关系。并基于试验结果建立数值分析模型，分析腐蚀坑处应力状态。轴向拉力作用下，带腐蚀缺陷管道钢的断裂位置发生在深宽比最大的腐蚀坑处；表面腐蚀缺陷管钢的屈服强度、弹性模量与腐蚀损失度相关度较低，而屈服荷载和等效弹性模量随着腐蚀程度的增加而明显降低；腐蚀坑的最大深宽比是影响管钢腐蚀坑处的应力集中系数的主要因素。研究结果可为在役管线力学性能进行评估预测，对预防管道泄漏及生命周期提供分析依据。

A Study on Mechanical Properties Degradation of Pipe Steel with Surface Natural Corrosion Defects

Corrosion has a certain effect on the mechanical properties of pipe steel. In this paper, tensile tests were carried out on pipeline steels with different degrees of corrosion, and the relationship between the mechanical properties and corrosion loss of pipeline steels with different degrees of corrosion was studied. Based on the test results, a numerical analysis model was established to analyze the stress state at the corrosion pit. Under the action of axial tension, the fracture position of the pipeline steel with corrosion defects occurs at the corrosion pit with the largest aspect ratio. The results show that the yield strength and elastic modulus of pipe steel with surface corrosion defects have a low correlation with corrosion loss degree, but the yield load and equivalent elastic modulus decrease obviously with the increase of corrosion degree. The maximum depth to width ratio of the corrosion pit is the main factor affecting the stress concentration factor at the corrosion pit. The research results can be used to evaluate and predict the mechanical properties of pipelines in service, and provide an analysis basis for the prevention of pipeline leakage and life cycle.