锈蚀高强度钢丝的力学性能与评级方法

为了建立高强度钢丝的锈蚀分级标准，以4座服役10 a以上的拱桥吊杆高强度钢丝样本为对象，在进行原状钢丝拉伸和疲劳试验研究的基础上，用刻痕方法模拟钢丝的表面蚀坑，通过有限元分析以及拉伸试验研究蚀坑形貌对钢丝力学性能的影响，建立蚀坑参数与钢丝极限应变的定量关系，提出考虑蚀坑形状的锈蚀钢丝评价标准。结果表明，锈蚀对钢丝弹性模量和极限强度的影响不敏感，但蚀坑引起钢丝的延性下降；锈蚀钢丝的延性下降程度与蚀坑部位的应力集中状况有关，用蚀坑形状参数可以较精确地评价钢丝受锈蚀影响的程度。

Mechanical properties and grading method of corroded high-tensile steel wires

In order to establish a grading method of corroded high-tensile steel wires, samples of steel wire served for more than a decade on four arch bridges were employed and the mechanical properties were investigated from the tensile and fatigue tests. The effect of pitting geometries was analyzed by finite element method (FEM) and tension test, and pits were simulated by means of notches on the surface of steel wires. According to the theoretical analysis and experimental results, the quantitative relationship between the pitting geometries and the ultimate strain of wire was proposed, and a grading method based on pitting geometries was developed. The results show that the elastic modulus and the ultimate strength of the wire are not sensitive to, while the ductility is significantly influenced by the pitting corrosion. Besides, stress concentration around the pitting is the cause of the decline in ductility of corroded high-tensile steel wires. The status of corroded wires can be evaluated precisely by the depth and shape of pits.