Wang Songquan, Zhang Dekun, Hu Ningning, Zhang Jialu
School of Mechatronic Engineering, Jiangsu Normal University, Xuzhou 221116, China.
School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou 221116, China.
Materials (Basel). 2016 Sep 1;9(9):750. doi: 10.3390/ma9090750.
In this work, the effects of loading condition and corrosion solution on the corrosion fatigue behavior of smooth steel wire were discussed. The results of polarization curves and weight loss curves showed that the corrosion of steel wire in acid solution was more severe than that in neutral and alkaline solutions. With the extension of immersion time in acid solution, the cathodic reaction of steel wire gradually changed from the reduction of hydrogen ion to the reduction of oxygen, but was always the reduction of hydrogen ion in neutral and alkaline solutions. The corrosion kinetic parameters and equivalent circuits of steel wires were also obtained by simulating the Nyquist diagrams. In corrosion fatigue test, the effect of stress ratio and loading frequency on the crack initiation mechanism was emphasized. The strong corrosivity of acid solution could accelerate the nucleation of crack tip. The initiation mechanism of crack under different conditions was summarized according to the side and fracture surface morphologies. For the crack initiation mechanism of anodic dissolution, the stronger the corrosivity of solution was, the more easily the fatigue crack source formed, while, for the crack initiation mechanism of deformation activation, the lower stress ratio and higher frequency would accelerate the generation of corrosion fatigue crack source.
在这项工作中，讨论了加载条件和腐蚀溶液对光滑钢丝腐蚀疲劳行为的影响。极化曲线和失重曲线结果表明，钢丝在酸性溶液中的腐蚀比在中性和碱性溶液中更严重。随着在酸性溶液中浸泡时间的延长，钢丝的阴极反应逐渐从氢离子还原转变为氧还原，但在中性和碱性溶液中始终是氢离子还原。通过模拟奈奎斯特图还获得了钢丝的腐蚀动力学参数和等效电路。在腐蚀疲劳试验中，强调了应力比和加载频率对裂纹萌生机制的影响。酸性溶液的强腐蚀性会加速裂纹尖端的形核。根据侧面和断口形貌总结了不同条件下裂纹的萌生机制。对于阳极溶解的裂纹萌生机制，溶液腐蚀性越强，疲劳裂纹源越容易形成，而对于变形激活的裂纹萌生机制，较低的应力比和较高的频率会加速腐蚀疲劳裂纹源的产生。
