摘要
为了研究2507双相不锈钢在海水脱硫环境中的耐腐蚀性能,利用开路电位、电化学阻抗谱、动电位极化法、恒电位极化法、Mott-Schottky曲线和扫描电镜等研究了2507双相不锈钢在海水脱硫环境中的腐蚀行为。结果表明:2507双相不锈钢在海水脱硫环境中的腐蚀形式为点蚀。随着NaHSO_(3)浓度的增大,2507双相不锈钢的开路电位、自腐蚀电位E_(corr)和点蚀击穿电位E_(b)负移,钝化膜电阻R_(ct)减小,腐蚀电流密度I_(corr)增大,耐腐蚀性能下降。HSO_(3)^(-)与Cl^(-)的竞争吸附对点蚀具有协同促进作用,HSO_(3)^(-)参与钝化膜的钝化过程并形成金属硫酸盐,钝化膜点缺陷密度增大,载流子密度增大,导电性提高,钝化膜屏蔽作用下降。
In order to study the corrosion resistance of 2507 duplex stainless steel in seawater desulfurization environment,the corrosion behavior of the 2507 duplex stainless steel in seawater desulfurization environment was studied by means of open circuit potential,electrochemical impedance spectroscopy,potentiodynamic polarization,potentiostatic polarization,Mott-Schottky curve and scanning electron microscopy.The results show that the corrosion form of the 2507 duplex stainless steel in seawater desulfurization environment is pitting corrosion.With the increase of NaHSO_(3) concentration,the open circuit potential,self corrosion potential E_(corr) and pitting breakdown potential E_(b) of the 2507 duplex stainless steel move negatively,the passive film resistance R_(ct) decreases,the corrosion current density I_(corr) increases,and the corrosion resistance decreases.The competitive adsorption of HSO_(3)^(-) and Cl^(-) has a synergistic promotion effect on pitting corrosion.HSO_(3)^(-) participates in the passivation process of the passive film and forms metal sulfate,which leads to the increase of point defect density,carrier density and electrical conductivity,and the decrease of shielding performance of the passive film.
作者
余翠兰
张钰柱
宋斌杰
YU Cui-lan;ZHANG Yu-zhu;SONG Bin-jie(College of Intelligent Engineering,Chongqing College of Mobile Communication,Chongqing 401520,China;Beijing ABB Power System Co Ltd,Beijing 101300,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2023年第1期95-107,共13页
Transactions of Materials and Heat Treatment
基金
重庆市教委科学技术研究项目(KJQN202002402)。
关键词
2507双相不锈钢
海水脱硫
点蚀
钝化膜
耐腐蚀性能
2507 duplex stainless steel
seawater desulfurization
pitting corrosion
passive film
corrosion resistance
