Abstract: In view of the variation rule of magnetic signal of steel strand with two corrosion points and the interaction between corrosion points, four groups of specimens with different spacings were designed. The corrosion degree was controlled by electrochemical corrosion device, and the magnetic leakage signal was measured by three-dimensional magnetic signal scanning device. The research shows that the criterion of single corrosion region is also applicable to two corrosion regions. However, when the two points are close to each other, the superposition of the magnetic signals will occur and the extreme value will appear. Moreover, the intersection distance of the magnetic signal curve is positively correlated with the distance between the corrosion areas at different lift heights. The magnetic signal of the specimen changes abruptly in the corrosion area, and its variation range has a certain width. The distribution of the influence width and the corrosion degree is Boltzmann function. 此后英文替换The influence width of the curve can be used to evaluate the corrosion degree of a single corrosion zone and to determine the minimum spacing between two corrosion zones without superposition under a given degree of corrosion.

Key words: bridge engineering, spontaneous magnetic flux leakage, nondestructive testing, steel strand, corrosion

摘要： 为研究存在两腐蚀点时钢绞线磁信号的变化规律以及腐蚀点之间的相互影响，设计了4组不同间距的试件，利用电化学腐蚀装置控制腐蚀程度，再通过三维磁信号扫描装置测试漏磁信号。研究表明：单个腐蚀区域的判断准则也适用于两个腐蚀区域；距离较近的两腐蚀区域的磁信号会在两点之间产生叠加，出现极值，且不同提离高度下磁信号曲线的汇交距离与腐蚀区域的间距呈正相关；试件在腐蚀区域会发生磁信号的突变，其变化范围具有一定宽度，该影响宽度与试件腐蚀度呈Boltzmann函数分布，可用该曲线影响宽度评价单个腐蚀区域的腐蚀程度，也可用于确定两个腐蚀区域在确定特定腐蚀度下不产生叠加的最小间距。

关键词: 桥梁工程, 自发漏磁, 无损检测, 钢绞线, 腐蚀