**3.3 Steel wire corrosion fatigue loss of weight**

In order to facilitate data processing, the problem of uneven distribution of steel wire density along the axial direction is ignored, and the weight of the steel wire is converted to unit length weight. And use the same method to deal with the corrosion of the steel wire, the data of weight loss over time before and after corrosion are recorded separately (**Table 3**) [14]. The table shows the weight *W*<sup>1</sup> before corrosion, weight *W*<sup>2</sup> after corrosion, weightlessness *W*3, diameter *D*<sup>1</sup> after corrosion, average diameter *D*2, and corrosion time *H*.

It can be seen from the experimental data, the weight of the steel wire is reduced over time in the experiment, and the growing trend of different stress states of the steel wire is basically the same. In the three stress states, although the weight loss per unit area at a particular moment is not very regular, according to their respective trends to analyze, the overall still follow such a law: In any stage of corrosion of the steel wire, the stress complex steel wire in a corrosive environment is more vulnerable to corrosion.


**Table 3.**

*Steel wire corrosion fatigue loss of weight date [14].*

**Figure 4.** *Relationship between corrosion time and average diameter of each group [13].*

Considering the fatigue effect of the wire, alternating stress is not only easy to cause fatigue damage to the steel wire but also may accelerate the chemical corrosion of its surface in a corrosive environment, causing a decrease in the cross-sectional area of steel wire, increasing the stress on the steel wire, and reducing the safety factor of the cable.

Without considering the stress state of the steel wire, the relationship between the diameter of the corroded steel wire and time is plotted in **Figure 4**.

As can be seen from **Figure 4**, the trend of decreasing the diameter of corroded steel wire is linear. The corrosion time is 5 days, and the diameter of the steel wire is 5.23 mm, greater than the standard diameter of the steel wire 5.2 mm, which is due to the fact that the zinc layer thickness will be slightly higher than the specified value in order to protect the quality of the steel wire [13]. The actual experimental wire diameter before corrosion is between 5.23 mm and 5.25 mm, and the effect of 5 days of corrosion on the diameter is not significant, measured with a micrometer will also produce a certain error.
