Effect of Nitrate and Sulfate on Atmospheric Corrosion of 304L and 316L Stainless Steels
Effect of Nitrate and Sulfate on Atmospheric Corrosion of 304L and 316L Stainless Steels
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DOI：
10.1149/2.0921704jes
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发表时间：
2017-01-01
影响因子：
3.9
通讯作者：
Davenport, Alison J.
中科院分区：
文献类型：
--
作者：
Cook, Angus J. M. C.;Padovani, Cristiano;Davenport, Alison J.
采用自动沉积法研究了硝酸盐和硫酸盐对304L和316L不锈钢在氯离子环境下的孔蚀行为的影响。当硝酸根阴离子和氯离子的沉积密度之比超过一个临界值时，硝酸根对304L和316L的点蚀有抑制作用。发现这个临界比随着湿度的增加而减小。硫酸盐也被观察到抑制点蚀的MgCl2 + MgSO4混合物，但仅在较高的湿度。硫酸盐对CaCl2 + CaSO4混合物没有任何抑制作用，这是由于CaSO4的溶解度低。在低相对湿度下，观察到抑制盐的沉淀，在某些情况下导致盐晶体下的缝隙状腐蚀。用浓溶液的热力学行为解释了点蚀行为。(C)作者（S）2017由ECS发布。All rights reserved.
The effects of nitrate and sulfate salts on the chloride-induced atmospheric pitting corrosion of 304L and 316L stainless steel was investigated through automated deposition of droplets of magnesium and calcium salts. Nitrate was found to inhibit pitting under magnesium salt droplets when the ratio between the deposition density of nitrate anions and chloride anions was above a critical value, which was the same for both 304L and 316L. This critical ratio was found to decrease with increasing humidity. Sulfate was also observed to inhibit pitting for MgCl2 + MgSO4 mixtures, but only at higher humidities. Sulfate did not show any inhibition for CaCl2 + CaSO4 mixtures, an effect attributed to the low solubility of CaSO4. At low relative humidities, precipitation of the inhibiting salt was observed, leading in some cases to crevice-like corrosion under salt crystals. The pitting behavior was explained in terms of the thermodynamic behavior of concentrated solutions. (C) The Author(s) 2017. Published by ECS. All rights reserved.