汽车动态加速腐蚀环境对热轧钢板的腐蚀行为影响

Effect of Vehicle Dynamic Accelerated Corrosion Environment on Corrosion Behavior of Hot Rolled Steel Sheet

研究了热轧钢板(SPHC)在汽车动态行驶、盐雾喷洒及温湿度环境仓下的腐蚀速率,并用扫描电子显微镜分析了经过5天、7天和20天试验的SPHC钢锈层的微观形貌。结果显示,汽车动态加速腐蚀环境下,相对湿度交变运行下的SPHC钢的腐蚀速率要高于相对湿度单一运行,而两者的腐蚀速率均随试验时间呈现出相似的非线性变化趋势。在试验的第1到5天,腐蚀速率迅速增加,锈层表面和内部出现了许多裂纹,这是腐蚀过程的初期加速阶段;当试验进行到第7天时,腐蚀速率开始下降,此时锈层比较密实,增强了SPHC钢的抗腐蚀性能;然而,当试验持续至第20天时,腐蚀速率再次上升到一个较高水平,锈层开始剥落,基体也受到严重腐蚀,因此耐蚀性最差。

The corrosion rate of hot rolled steel plate(SPHC)under dynamic driving,salt spray and temperature and humidity environment was studied.The microstructure of SPHC steel rust layer after 5 days,7 days and 20 days of test was analyzed by scanning electron microscope.The results show that the corrosion rate of SPHC steel under dynamic accelerated corrosion environment is higher than that under single operation,and the corrosion rate of both of them shows a nonlinear change trend with the test time.In the first five days of the test,the corrosion rate increased rapidly,and many cracks appeared on the surface and inside of the rust layer,which was the initial acceleration stage of the corrosion process.On the 7th day of the test,the corrosion rate began to decline,and the rust layer was relatively dense,which enhanced the corrosion resistance of SPHC steel.However,when the test continued to the 20th day,the corrosion rate again rose to a higher level,the rust layer began to peel off,the matrix was also seriously corroded,so the corrosion resistance was the worst.