摘要
拜耳法处理高硫铝土矿生产氧化铝过程中,NaOH浓度、S^(2-)浓度、腐蚀时间等因素对设备钢材的腐蚀产生一定的影响。为此,采用电化学和失重腐蚀方法研究NaOH浓度对16Mn钢腐蚀行为的影响,采用扫描电镜分析产物微观形貌,根据元素分布情况分析腐蚀产物的成分变化规律。结果表明:16Mn钢的腐蚀速率随着NaOH浓度的升高而增加,达到最大值后有所减小,NaOH浓度为245 g/L时腐蚀速率最大。随NaOH浓度从235 g/L增加到245 g/L,16Mn钢的容抗弧半径减小,此时腐蚀主要受电荷转移控制,主要发生S^(2-)的吸附;当NaOH浓度为255 g/L时阻抗谱出现典型的韦伯扩散现象,腐蚀过程主要受离子扩散和电荷转移共同控制,主要发生OH-的吸附。
In the process of alumina production from bauxite with high sulfur content by Bayer process,some factors such as NaOH concentration,S^(2-)concentration and corrosion time have certain effects on the corrosion of equipment steel.The corrosion behavior of 16 Mn steel under different NaOH concentrations was studied by electrochemical and weightless corrosion methods.The SEM was used to analyze the microscopic appearance of the corrosion products,the change rule of the composition of the corrosion products was analyzed according to the distribution of elements.Results showed that the corrosion rate of 16 Mn steel increased with the increase of NaOH concentration,and decreased after reaching the maximum value.When the NaOH concentration was equal to 245 g/L,the corrosion rate was the maximum.The impedance arc radius began to decrease with the increase of NaOH concentration from 235 g/L to 245 g/L.The corrosion was mainly controlled by charge transfer,and the adsorption of S^(2-)mainly occurred.When the NaOH concentration was equal to 255 g/L,the impedance spectrum showed a typical Warburg diffusion phenomenon.The corrosion process was mainly controlled by both ion diffusion and charge transfer,and the adsorption of OH-mainly occurred.
作者
周嫄
周斌
邹用强
潘晓辉
权变利
ZHOU Yuan;ZHOU Bin;ZOU Yong-qiang;PAN Xiao-hui;QUAN Bian-li(College of Materials and Metallurgy,Guizhou University,Guiyang 550025,China;Guizhou Province Key Laboratory of Metallurgical Engineering and Process Energy Saving,Guiyang 550025,China)
出处
《材料保护》
CAS
CSCD
2021年第5期170-175,共6页
Materials Protection
基金
国家自然科学基金(51474079)
贵州大学引进人才科研项目(贵大人基合字(2019)43号)
贵州大学“SRT计划”项目(贵大SRT字(2018)315号)资助。