Abstract: In this paper, the corrosion rate of steel plate heat-commercial (SPHC) steel after running in temperature and humidity in the dynamic driving process of a car is analyzed by scanning electron microscopy (SEM), and the microscopic morphology of the rust layer of SPHC steel after 7 days, 11 days and 15 days of testing is used to initially explore the corrosion change rule of SPHC steel under specific working conditions. The results show that the corrosion rate of SPHC steel spraies with 3% NaCl per day is higher than that of 0.5% NaCl under simulated vehicle dynamic conditions, but the corrosion rate of both steel shows the same trend of nonlinear change with the test time. When the test time is from 1 to 7 days, the corrosion rate first increases sharply, and the surface and middle of rust layer have a large number of cracks, which is the initial accelerated corrosion at this time. When the test time reached 11 days, the corrosion rate drops to the low point, and the rust layer is relatively dense, which enhanced the corrosion resistance of SPHC steel. When the test time reached 15 days, the corrosion rate rises the high point again. At this time, the rust layer peels off, the matrix is severely corroded, and the corrosion resistance is the worst.

Key words: SPHC steel; Automobile dynamic conditions; Environment warehouse; Corrosion behavior

摘要： 文章通过热轧钢板（SPHC）钢在汽车动态行驶过程中，经过温湿度环境仓运行后的腐 蚀速率，并采用扫描电子显微镜（SEM）检测手段分别分析了 SPHC 钢经历 7 天、11 天、15 天试验后的锈层微观形貌，初步探究 SPHC 钢在特定工况下的腐蚀变化规律。结果表明，在 模拟汽车动态工况下，SPHC 钢每天喷 3% NaCl 的腐蚀速率要高于 0.5% NaCl，但是两者的腐 蚀速率都随着试验时间呈现相同趋势的非线性变化。当试验 1 天至 7 天时，腐蚀速率先急剧 增大，锈层表面及其中间具有大量的裂纹，此时为初期加速腐蚀；当试验到 11 天时，腐蚀速 率下降到低点，此时锈层较为致密，增强了 SPHC 钢的耐蚀性；当试验到 15 天时，腐蚀速率 又上升到一个高点。此时锈层剥落，基体严重腐蚀，耐蚀性最

关键词: SPHC 钢；汽车动态工况；环境仓；腐蚀行为