铝酸钠溶液中Na_2S_2O_3对16Mn钢的腐蚀行为影响  

Effect of Sodium Thiosulfate on Corrosion Behavior of 16Mn Steel in Sodium Aluminate Solution

作　　者：杨夏琼 陈朝轶[1,2] 李军旗[1,2] 权变利[1,2] 刘利[1,2] 卢小玉 

机构地区：[1]贵州大学材料与冶金学院,贵阳550025 [2]贵州省冶金工程与过程节能重点实验室,贵阳550025

出　　处：《表面技术》2016年第6期173-179,共7页Surface Technology

基　　金：国家自然科学基金(51574095;51264006;51474079;51464008);贵州省教育厅项目(黔教合重大专项字(2012)0002);贵州省校合作项目(LH[2014]7609);贵州大学研究生创新基金(研理工2016019);贵大SRT字(2015)147号~~

摘　　要：目的研究16Mn钢在不同S_2O_3^(2-)浓度的NaAlO_2溶液中的腐蚀行为。方法通过盐雾腐蚀、失重法、电化学腐蚀实验以及SEM、EDS等分析手段研究16Mn钢的腐蚀行为。结果 S_2O_3^(2-)质量浓度由3 g/L增加至7 g/L时,腐蚀速率从0.4990 g/(m^2·d)增大至0.5180 g/(m^2·d),最大点蚀深度从3.6μm增至4.5μm,腐蚀电流密度由0.648μA/cm2增至5.186μA/cm2,容抗弧半径逐渐减小。EDS分析可知,腐蚀产物主要由O、Al、S、Fe四种元素组成,其中Al、O元素含量较多,且随着S_2O_3^(2-)浓度的增加先升高后降低。结论铝酸钠溶液中S_2O_3^(2-)的存在会促进16Mn钢的腐蚀,S_2O_3^(2-)浓度变化对16Mn钢的腐蚀行为有显著影响,试样的腐蚀速率总体上随S_2O_3^(2-)浓度的增加呈上升趋势。当S_2O_3^(2-)质量浓度为3 g/L时,试样表面会生成Al(OH)3膜,对基体有一定的保护作用,腐蚀速率上升较缓慢;当S_2O_3^(2-)质量浓度升至4 g/L后,氧化膜被S_2O_3^(2-)穿透,腐蚀速率上升较快;但是当S_2O_3^(2-)质量浓度上升到5 g/L后,腐蚀速率增长较慢并趋于平缓。Objective To investigate the corrosion behavior of 16 Mn steel in sodium aluminate solution with differentS2O3^（2-） concentrations. Methods The corrosion behavior of 16 Mn steel was studied by salt spray corrosion, weight loss method, electrochemical corrosion test and analyzed by SEM, EDS. Results Corrosion rate was raised from 0.4990 g/（m2·d） to 0.5180 g/（m^2·d） and the maximum pitting depth rose from 3.6 μm to 4.5 μm, when the concentration of S2O3^（2-） increased from 3 g/L to 7 g/L, while the corrosion current density rose from 0.648 μA/cm2 to 5.186 μA/cm^2 and the radius of capacitive arc decreased gradually. According to EDS analysis, corrosion products were composed of four elements（O, Al, S, Fe）, the contents of Al, O were higher than those of the other elements and decreased after increased first with increase ofS2O3^（2-） concentration. Conclusion Existence of thiosulfate accelerated corrosion of 16 Mn steel in sodium aluminate solution. Corrosion behavior of 16 Mn steel was notably affected by the changing concentration ofS2O3^（2-）. Corrosion rate showed a trend of escalation with the increase ofS2O3^（2-） concentration. Corrosion rate increased slowly in 3 g/L S2O2- 3for matrix protected by Al（OH）3 coatings on the surface of sample. The oxidation coating was penetrated byS2O3^（2-） after theS2O3^（2-） concentration increased to 4 g/L, and the corrosion rate increased relatively fast. However, the corrosion rate increased slowly and tended to be stable after the concentration ofS2O3^（2-） increased to 5 g/L.

关 键 词：硫代硫酸根 16MN钢 极化曲线 铝酸钠溶液 盐雾腐蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]