摘要
目的通过模拟氧化铝生产过程中的母液蒸发条件,研究在含S_(2)O_(3)^(2–)的铝酸钠溶液中12Cr1MoV钢的腐蚀行为,探讨S_(2)O_(3)^(2–)浓度对腐蚀的影响。方法在高压反应釜中对12Cr1MoV钢进行浸泡腐蚀,考察钢的腐蚀速率、腐蚀产物形貌、元素分布及物相组成。结合交流阻抗和极化曲线测试,分析S_(2)O_(3)^(2–)浓度对12Cr1MoV钢的腐蚀影响。结果12Cr1MoV钢的腐蚀速率随着铝酸钠溶液中S_(2)O_(3)^(2–)质量浓度的增加而加快,质量浓度由1 g/L增加至5 g/L时,腐蚀速率由0.78 g/(m^(2)·d)增加至1.67 g/(m^(2)·d)。腐蚀产物主要由Fe、O及少量的Al和S元素组成。当S_(2)O_(3)^(2–)的质量浓度小于4 g/L时,腐蚀产物主要为Fe2O3、FeO和Fe(1‒x)AlxOOH(x≤0.19);当S_(2)O_(3)^(2–)的质量浓度大于4 g/L时,产物主要为Fe3O4及少量的Al2O3。Rf和Rct随S_(2)O_(3)^(2–)浓度的升高而先增大后降低,4 g/L时达到最大值,分别为1284Ω·cm^(2)和816Ω·cm^(2);5 g/L时,Rf和Rct分别降到963Ω·cm^(2)和434Ω·cm^(2)。腐蚀电流密度随S_(2)O_(3)^(2–)浓度的升高而逐渐增大,由1 g/L增加到5 g/L时,腐蚀电流密度由25.25μA/cm^(2)增加至238.28μA/cm^(2)并达到最大。极化曲线测量与高温浸泡获得的腐蚀速率规律一致。结论铝酸钠溶液中S_(2)O_(3)^(2–)浓度对12Cr1MoV钢的腐蚀速率产生重要影响,浓度的增大会加快钢的腐蚀速率。S_(2)O_(3)^(2–)的质量浓度为4 g/L时,钢表面生成的Fe3O4层对钢基体的保护作用最好。S_(2)O_(3)^(2–)浓度越大,12Cr1MoV钢的腐蚀电流密度越大。
The purpose of the research is to study the corrosion behavior of 12Cr1MoV steel in sodium aluminate solution containing S_(2)O_(3)^(2–)and explore the effect of S_(2)O_(3)^(2–)on corrosion behavior under simulated evaporation conditions of mother liquor in producing alumina oxide.By carrying out the immersion corrosion to the 12Cr1MoV steel in the high-pressure reaction kettle,the corrosion rate of the steel,the morphology of the corrosion products,distribution of elements,and phase composition are obtained.In order to study the effect of S_(2)O_(3)^(2–)concentration on the corrosion behavior of 12Cr1MoV steel,a polarization curve and AC impedance test are used.The increased in S_(2)O_(3)^(2–)concentration has accelerated the corrosion rate of 12Cr1MoV steel gradually.The concentration increases from 1 g/L to 5 g/L,and the corrosion rate increases from 0.78 g/(m^(2)·d)to 1.67 g/(m^(2)·d).Corrosion products are mainly composed of Fe and O elements and a small amount of Al and S elements.When the concentration is less than 4 g/L,Fe2O3,FeO and Fe(1‒x)AlxOOH(x≤0.19)are the main corrosion products;and when the concentration is more than 4 g/L,Fe3O4 and a small amount of Al2O3 are found.With the increasing concentration of S_(2)O_(3)^(2–),.Rf and Rct increase first and then decrease,and reaches the maximum value at 4 g/L,which are 1284Ω·cm^(2) and 816Ω·cm^(2),respectively.At 5 g/L,Rf and Rct drop to 963Ω·cm^(2) and 434Ω·cm^(2),respectively.When the concentration of S_(2)O_(3)^(2–)increases from 1 g/L to 5 g/L,the corrosion current density increases from 25.25μA/cm^(2) to 238.28μA/cm^(2)(maximum).The corrosion rate law obtained from the polarization curve test is consistent with the high temperature immersion law.The concentration of S_(2)O_(3)^(2–)in sodium aluminate solution has a profound effect on the corrosion rate of 12Cr1MoV steel.Increasing the concentration of S_(2)O_(3)^(2–)in the solution can accelerate the corrosion rate of 12Cr1MoV steel.When it is greater than 4 g/L,the Fe3
作者
苑京久
陈朝轶
李军旗
权变利
付慧
盖家萱
YUAN Jing-jiu;CHEN Chao-yi;LI Jun-qi;QUAN Bian-li;FU Hui;GAI Jian-xuan(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Key Laboratory of Metallurgical Engineering and Process Energy Saving of Guizhou Province,Guiyang 550025,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2021年第3期301-307,共7页
Surface Technology
基金
国家自然科学基金(U1812402,51664005,51774102,52074096)
黔科合平台人才计划([2017]5626,[2017]5778)
贵州省教育厅项目(黔教合KY[2015]334,黔教合YJSCXJH[2019]002)。
