在中性盐雾腐蚀环境中对Q235钢板进行0～178 d的加速腐蚀试验, 采用光学表面测量技术对锈蚀钢板表面进行数据采集, 运用Geomagic studio逆向工程软件建立了Q235钢板锈蚀表面的几何模型;通过单轴拉伸试验研究了Q235钢板力学性能的退化规律。结果表明: 随着锈蚀质量损失率增大, Q235钢板的屈服强度、抗拉强度和断后伸长率均呈明显的线性退化趋势, 屈服平台迅速缩短, 严重蚀坑的存在使得锈蚀钢板更易产生塑性损伤而进入颈缩阶段; 通过对二次塑流模型进行修正, 建立了锈蚀Q235钢板的应力-应变退化本构模型, 得到了模型形状控制参数随锈蚀质量损失率变化的退化规律; 在中性盐雾环境中, Q235钢板的腐蚀以点蚀为主, 蚀坑分布不均匀, 且具有较大的离散性和随机性, 腐蚀过程中层状剥蚀产生的影响不可忽略。

Accelerated corrosion test was carried out on Q235 steel plate in neutral salt spray corrosion environment for 0-178 days, and then the data of corroded steel plate surface were collected by using optical surface measurement technology to establish the corroded surface geometry model of Q235 steel plate by Geomagic studio. Degradation law of mechanical properties of Q235 steel plate were investigated by uniaxial tensile tests. The results show that yield strength, tensile strength and elongation obeyed a linear degradation with the increase of corrosion mass loss ratio, the yield platform became shorter rapidly. The corroded steel plate with big pits more easily entered its stage of necking because of plastic damage. By modifying the second plastic flow model, the stress-strain constitutive degradation model of corroded Q235 steel plate was established, and the degradation law of the model shape control parameters based on the corrosion mass loss ratio was achieved finally. In neutral salt spray corrosion environment, the main corrosion feature of Q235 steel plate was pitting corrosion, corrosion pit exhibited uneven distribution, separate characteristic and randomness, however, the effect of layered erosion could not be ignored.