摘要
为了评价2507超级双相不锈钢在低温多效海水淡化装置中的适用性,通过扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)和电化学测试等研究了2507超级双相不锈钢在不同温度高浓度海水中的耐腐蚀性能。结果表明:在不同温度的2倍浓度的海水中,2507超级双相不锈钢发生选择性点蚀,铁素体相为腐蚀弱相,点蚀分布在铁素体相区域。随着2倍浓度海水的温度从20℃升高至70℃,2507超级双相不锈钢的自腐蚀电位、点蚀电位和再钝化电位分别降低87、142和168 mV,腐蚀电流密度增大约1倍,低频阻抗模值减小约0.44倍。恒电位极化生成的钝化膜组成均为Fe、Cr、Mo和Ni的氧化物和氢氧化物,温度的升高促进钝化膜中Fe的溶解和Cr、Mo和Ni的富集,钝化膜的施主密度和受主密度略微增大。虽然2507超级双相不锈钢在高温高浓度海水中的耐腐蚀性能略微下降,但仍然维持较好的耐腐蚀性能,其适用于低温多效海水淡化装置的建造材料。
In order to evaluate the applicability of 2507 super duplex stainless steel in low-temperature and multi-effect seawater desalination equipment,its corrosion resistance in high concentration seawater at different temperatures was studied by means of scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)analysis,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and electrochemical testing.The results show that the corrosion type of the 2507 duplex stainless steel in simulated artificial seawater with two-fold concentrations at different temperatures is the selective pitting,with the ferrite phase being the weak corrosion-resistant phase,and pitting corrosion is distributed in the ferrite phase region.As the temperature of seawater with two-fold concentration increases from 20℃to 70℃,the self-corrosion potential,pitting potential and repassivation potential of the 2507 duplex stainless steel decrease by 87,142 and 168 mV,respectively,the corrosion current density increases by about one time,and the low-frequency impedance modulus decreases by about 0.44 times.The passive film generated by potentiostatic polarization consists of oxides and hydroxides of Fe,Cr,Mo and Ni.The increase in the temperature promotes the dissolution of Fe and the enrichment of Cr,Mo,and Ni in the passive film,and the donor density and acceptor density of the passive film slightly increase.Although the corrosion resistance of the 2507 super duplex stainless steel slightly decreases in high-temperature and high-concentration seawater,it still maintains good corrosion resistance,which shows that it is suitable as a construction material for low-temperature and multi-effect seawater desalination devices.
作者
林波
赵鹏展
LIN Bo;ZHAO Peng-zhan(Auto Engineering Department,Chongqing College of Science and Creation,Chongqing 402160,China;School of Information and Intelligent Manufacturing,Chongqing City Vocational College,Chongqing 402160,China)
出处
《材料热处理学报》
CAS
CSCD
北大核心
2024年第12期167-177,共11页
Transactions of Materials and Heat Treatment
基金
重庆市教育委员会科学技术研究项目(KJQN202305414)
重庆市教育委员会科学技术研究计划青年项目资助项目(KJQN202303910)
重庆市教育委员会科学技术研究项目(KJQN202205401)。
关键词
2507超级双相不锈钢
低温多效海水淡化
高温高浓度海水
耐腐蚀性能
2507 super duplex stainless steel
low-temperature and multi-effect seawater desalination
high temperature and high concentration seawater
corrosion resistance
