对16块Q235B钢板进行了模拟近海大气环境加速腐蚀实验，利用非接触式表面形貌测试方法与自编程序对其表面形貌与特征参数进行采集与分析，明确锈蚀深度、锈坑深度、锈坑径深比分布特征，揭示其均值、方差等统计参数及锈坑形状的变化规律。研究表明，模拟近海大气环境下结构钢腐蚀过程大致经历疮痂、鼓包、剥落3个阶段，疮痂和鼓包阶段以点蚀为主，剥落阶段则表现出全面腐蚀特征；锈蚀深度服从正态分布，锈坑深度和径深比服从对数正态分布；随着腐蚀程度的增大，锈蚀深度均值、标准差与功率谱密度峰值以及锈坑深度对数均值均逐渐增大，锈坑径深比对数均值逐渐减小；各龄期内圆锥体锈坑占比最高，锈坑形状由圆柱或半球体逐渐向圆锥体转变。最后基于锈蚀深度和锈坑参数统计规律，建立了锈蚀深度随机场模型(SFCD)和锈坑随机分布模型(RDCP)，实现了模拟近海大气环境锈蚀钢材表面形貌重建。

Steel structures exposed to offshore atmospheric environment for a long time inevitably suffer from corrosion damage. Safety assessment of corroded steel structures largely depends on the quantification of corroded surface features as the irregular corrosion characteristics are the main factors causing decline in steel mechanical properties. To investigate the structural steel corrosion characteristics in offshore atmospheric environment, accelerated corrosion tests were conducted on 16 pieces of Q235B steel plates by periodic spraying to simulate the offshore atmospheric environment. Moreover, the surface morphologies and characteristic parameters were measured and analyzed using a ST400 3D Noncontact Profilometer and a self-written algorithm. The distribution characteristics such as corrosion depth, pit depth, and aspect ratio were elucidated, and the changing laws of statistical parameters such as mean value, standard deviation, and pitting shapes were revealed. The results indicated that in the simulated offshore atmospheric environment, the structural steel corrosion process generally goes through three stages: scab, swell, and spall. The scab and swell stages are dominated by pitting corrosion, whereas, the spall stage shows the general corrosion characteristics. Moreover, the corrosion depth of structural steel in the simulated offshore atmospheric environment conforms to the normal distribution, whereas, the pit depth and aspect ratio conform to the log-normal distribution. As the degree of corrosion increases, the mean value and standard deviation of the corrosion depth, peak value of the power spectral density of the corrosion depth, and logarithmic mean value of the pit depth also gradually increase, whereas, the logarithmic mean value of the pit aspect ratio decreases. Meanwhile, at different ages, the cone pits have the highest proportion, and the pit shape gradually changes from a cylinder or a hemisphere to a cone. Finally, based on the results of the statistical analysis of the corrosion depth and pit parameters, the stochastic field model of corrosion depth and random distribution model of corrosion pits were constructed, which achieved the accurate characterization and reproduction of the surface morphology of the corroded steel in a simulated offshore atmospheric environment. The research results would lay the foundation for the establishment of an accurate stochastic model and structural reliability analysis in the natural offshore atmospheric environment.