目前常用的腐蚀速率测量方法有电化学测量法以及重量法，但在早期腐蚀阶段其测量准确性有限。针对该问题，以Q235钢在pH值为5的3.5%NaCl介质中的腐蚀行为为研究对象，通过传统的电化学阻抗谱分析了早期腐蚀动力学行为，通过法拉第定律计算了腐蚀速率。进一步开展静态浸泡试验，采用激光共聚焦显微镜测得体积缩减，测量浸泡样品的腐蚀失重，并换算为腐蚀速率。通过对比电化学测试法、失重法和体积缩减法的结果，发现在早期浸泡阶段，体积缩减法可以获得更为准确的腐蚀速率，为其余2种方法进行修正。

Electrochemical measurement and mass loss have been applied to acquire the corrosion rate, but the accuracy is limited when the corrosion is in its early stages. In this study, the early stages corrosion behavior of Q235 steel in 3.5% NaCl solution with pH=5 was investigated. The early stages corrosion kinetics behavior was obtained by traditional electrochemical approach, and the corrosion rate was calculated by Faraday’s law. Furthermore, the samples were carried out by conventional static immersion test. Subsequently, the volume reduction was measured by laser scanning confocal microscope (LSCM), the weight loss was also obtained. By comparing the corrosion rates obtained by these methods, it was obtained that corrosion rate in early stages obtained by volume reduction was the most accurate, which could be used to revise the corrosion rate obtained by other methods.