NaCl在A3钢大气腐蚀中的作用

ROLE OF NaCl IN THE ATMOSPHERIC CORROSION OF A3 STEEL

研究了温度为 2 5℃、相对湿度为 80 %时NaCl对A3钢大气腐蚀的影响 .结果表明 ,A3钢腐蚀失重随NaCl沉积量的增加而增加 ,同时随暴露时间的延长也呈增加趋势 ;但暴露一定时间后 ,腐蚀失重增加趋缓 .采用扫描电镜(SEM /EDAX)及光电子能谱 (XPS)对腐蚀形貌及产物成分进行了分析 ,腐蚀表面呈现不均匀的凹凸形貌 ,腐蚀产物上有细微裂缝 .探讨了该条件下A3钢的大气腐蚀过程 .

The effect of NaCl deposition on the atmospheric corrosion of A3 steel at 25℃ and 80%RH was investigated.The results showed that weight loss increased with the amount of NaCl deposition,but it did not change obviously in the presence of more amount of NaCl deposition after exposure for certain time.Scanning electron microscopy(SEM),electron dispersion X-ray analysis(EDAX)and X-ray photoelectron spectroscopy(XPS)were used to study the morphology,element composition and valence on the corrosion surface.The surfaces were obviously uneven,and some tiny crevices appeared in corrosion products that can help O 2 transmit to inner layer.A brief corrosion mechanism was presented to explain the experimental observations under this condition.