The research for intensity of corrosive fatigue under changing tensile force according to method of electric chemistry of cable structure in ocean

腐蚀速度与S-N曲线的实验结果。通过电化学的方法，可以要求电缆钢在潮湿环境下的腐蚀速度。它清楚地显示了两者的区别。通过在25 C， 3%NaCL溶液中的腐蚀疲劳实验和空气中的疲劳实验，对电缆钢的S-N曲线进行弯曲，在腐蚀的情况下，如果我们使腐蚀速度比自然腐蚀快15倍，它将在20亿次后断裂。与此同时，它的持久性表明，其中12%在空气中，95%的部分将被破坏。裂纹扩展的实验结果。不同的环境会改变疲劳裂纹扩展的da/dN-DELTAK关系。我们还可以用电流电位法测量腐蚀溶液中的裂纹长度。为了解释腐蚀疲劳情况下裂纹的开闭现象，我们进行了各种实验。通过有效应力强度因子可以清晰地显示实验中的Kop点，从而对数据进行整理。利用扫描显微镜观察断裂面、裂纹扩展长度和疲劳破坏，可以观察到第一裂纹的闪烁面、第二通道的条纹和第三通道的韧窝波前。

Experimental results about corrosion speed and S-N curve. It'll be possible that we can request the corrosion speed of cable steel under moisture environment through the method of electric chemistry. And it shows the difference clearly. Curving the S-N of cable steel through the effect of corrosive fatigue experiment in 25ﾟC、3%NaCL solution and the fatigue experiment in air, In the case of corrosion, if we make the corrosion speed 15 times faster than the natural corrosion, it will be broken after 2000 million times. In the meantime, its persistence shows 12 percent of which is in air, and 95 percent of the section will be broken.Experiment results about crack growth. The relationship of da/dN-DELTAK about fatigue crack growth will be changed because of different environment. We can also measure the length of crack in corrosion solution by means of current potential method. In order to interpret the phenomenon about the crack opening and closing which is happened in the case of corrosive fatigue, we have been able to make kinds of experiments. And we can show the Kop point clear under experiment so as to put the data in order through the effective stress intensity factor. Using the scanning microscope to observe the broken plane and the length of crack growth and fatigue destruction, we can observe the first crack glinding plane and the striation of the second passage and the wave front of dimple of third passage.