U71Mn钢轨在中性NaCl溶液中的初期腐蚀行为探析  

Exploration of Initial Corrosion Behaviors of U71Mn Steel Rails in Neutral NaCl Solution

作　　者：何成刚 干耀哲 刘海乔 董鸿铭 刘吉华 徐志彪 黄尊地 HE Chenggang;GAN Yaozhe;LIU Haiqiao;DONG Hongming;LIU Jihua;XU Zhibiao;HUANG Zundi(School of Railway Tracks and Transportation,Wuyi University,Jiangmen 529020,China)

机构地区：[1]五邑大学轨道交通学院,广东江门529020

出　　处：《材料保护》2024年第7期109-118,共10页Materials Protection

基　　金：广东省教育厅特色创新项目(2023KTSCX151);五邑大学创新创业基金项目(2023111500000421);五邑大学港澳联合研发基金项目(2021WGALH15)资助。

摘　　要：为研究钢轨腐蚀行为与NaCl溶液浓度及腐蚀时间的关系,以U71Mn钢轨为对象,采用全浸试验和电化学测试方法探究了钢轨材料浸泡在1.0%、2.0%、2.5%、3.5%、4.0%和5.0%不同浓度的中性NaCl溶液中144 h及在中性3.5%NaCl溶液中浸泡12、48、96、144、192和288 h的初期腐蚀行为和机理。结果表明:初期钢轨材料的平均腐蚀速率与NaCl浓度和浸泡时间均呈正相关关系。随着NaCl浓度的增加,钢轨试样的E_(corr)从-0.651 V负向移动至-0.717 V,J_(corr)从5.71μA/cm_(2)增大至67.48μA/cm_(2);随着腐蚀时间的延长,钢轨试样的E_(corr)从-0.692 V负向移动至-0.720 V,J_(corr)从7.54μA/cm_(2)增大至74.59μA/cm_(2),其中腐蚀产物γ-FeOOH的还原会破坏原有稳定的锈层结构,最后造成腐蚀的加速。In order to study the relationship between the corrosion behavior of steel rails and the concentration and corrosion time of NaCl solution,U71Mn steel rails were taken as the object,and the initial corrosion behavior and mechanism of steel rail materials immersed in neutral NaCl solutions(different concentrations of 1.0%,2.0%,2.5%,3.5%,4.0%and 5.0%)for 144 h,and in neutral 3.5%NaCl solutions for various immersion times(12,48,96,144,192,288 h)were investigated by full immersion test and electrochemical tests.Results showed that the average corrosion rate of initial steel rail materials was positively correlated with NaCl concentration and immersion time.With the increase of NaCl concentration,the E_(corr)of the steel rail specimen moved negatively from-0.651 V to-0.717 V,and the J_(corr)increased from 5.71μA/cm_(2)to 67.48μA/cm_(2).With the increase of corrosion time,the E_(corr)of the steel rail specimen moved negatively from-0.692 V to-0.720 V,and the J_(corr)increased from 7.54μA/cm_(2)to 74.59μA/cm_(2).Furthermore,the reduction of corrosion productsγ-FeOOH could destroy the original stable rust layer structure,and finally causing the acceleration of corrosion.

关 键 词：U71Mn钢轨 全浸试验 中性NaCl溶液 腐蚀行为 电化学 

分 类 号：TG172[金属学及工艺—金属表面处理]