Influence of Ni, Mo, and Cr on Pitting Corrosionof Steels Studied by Raman Spectroscopy
Influence of Ni, Mo, and Cr on Pitting Corrosionof Steels Studied by Raman Spectroscopy
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DOI：
10.5006/1.3315974
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发表时间：
1992-07
期刊：
影响因子：
1.6
通讯作者：
N. Boucherit;A. H. Goff;S. Joiret
中科院分区：
文献类型：
--
作者：
N. Boucherit;A. H. Goff;S. Joiret
摘要用拉曼光谱法对不锈钢（AISI 302，316）在含氯碱性溶液中点蚀电位极化后的腐蚀层进行了鉴定。研究了几种二元合金，如Fe-10 Ni，Fe-6 Mo和Fe-18 Cr，以分离不同合金元素的影响。还与通过伏安循环（其允许钝化层增厚）在这些合金上形成的层进行比较，在这种情况下阳极反向电位低于点蚀电位。介绍了Cr和Mo这两种主要元素所起的作用。在被动性崩溃之后，即，一旦氧化铬层被破坏，则内层由四价钼形成，点蚀的发生与Mo从6+价到4+价的转变有关。在外部的绿色锈层中，重铬酸根离子填充了可供Cl-存在的位点，然后减缓了氯化物的进入。
Abstract Corrosion layers grown on stainless steels (AISI 302, 316), polarized at the pitting potential in alkaline solutions containing chloride, were identified by Raman spectroscopy. Several binary alloys such as Fe-10Ni, Fe-6Mo, and Fe-18Cr, were studied to separate the influence of the different alloy elements. A comparison was also made with the layers formed on these alloys by voltametric cycling (which allows the thickening of the passive layer), the anodic reverse potential being in this case below the pitting potential. The parts played by the two main elements, Cr and Mo, are described. After the passivity breakdown, i.e., once the chromia layer has broken down, the inner layer is formed by tetravalent molybdate, the pitting initiation being related to the passage of Mo from valency6+ to valency4+. In the outer green rust layer, bichromate ions fill the sites available for Cl− and then slow down the ingress of chloride.