大気環境中にてSUS 304ステンレス鋼に生成する不働態皮膜におよぼす微量塩類の影響

鄭, 楽薫; 土谷, 博昭; 藤本, 愼司

材料と環境, 2013, 62(4), 148-152

Number of Access:829（2025-11-20 12:58 Counts）

Identifier to cite or link to this item: https://hdl.handle.net/11094/82365

Link to primary information 

File Format Terms of use Size Views Date.Available Description information
ztk_62_4_148 pdf None 649 KB 180 2021.07.08  

Item Information

Output File Export EndNote Basic Export Mendeley

Title
大気環境中にてSUS 304ステンレス鋼に生成する不働態皮膜におよぼす微量塩類の影響
Effect of Trace Amounts of Salts on Properties of Passive Films Formed on SUS 304 Stainless Steel under Atmospheric Environment
Creator
CreatorName
鄭, 楽薫 ; Jung, Rock-Hoon
NRID
1000050432513 1000050432513
ORCID
0000-0001-5619-0139 0000-0001-5619-0139
researchmap permalink
read0076368 read0076368
Scopus Author ID
7202203364 7202203364
CreatorName
土谷, 博昭 ; Tsuchiya, Hiroaki
NRID
1000070199371 1000070199371
ORCID
0000-0002-7787-4190 0000-0002-7787-4190
researchmap permalink
read0013980 read0013980
Scopus Author ID
57211614674 57211614674
CreatorName
藤本, 愼司 ; Fujimoto, Shinji
Subject
不働態皮膜
相対湿度
水薄膜
塩化物
X線光電子分光
選択溶解
クロム濃化
孔食
passive films
relative humidity
thin water layer
chloride
X-ray photoelectron spectroscopy
selective dissolution
chromium enrichment
pitting corrosion
Abstract
SUS304ステンレス鋼に各種塩の希薄水溶液を塗布した試料を大気環境を模擬した相対湿度90％，60℃の恒温恒湿環境に保持し，不働態皮膜を光電子分光法にて解析した．不働態皮膜の厚さとCr濃度は微量塩類の影響を受けた．この環境中で，ステンレス鋼表面に生成する水薄膜の厚さは塗布した塩の飽和溶液の平衡相対湿度に対応して変化するとみられる．すなわち低い平衡相対湿度の塩を塗布した試料ほど厚い水膜を生成し，その結果Feの選択溶解が進行し，よりCr分率の大きな不働態皮膜を形成する．塩化物はCr濃縮を促進するが，高濃度となると局部腐食を発生した．塩化物を塗布した場合，生成する不働態皮膜は条件次第では高い耐局部腐食性を示すことがあった．硫酸塩もFeの選択溶解を促進するが局部腐食を生じることはなく，不働態皮膜は安定に成長した．
Passive films formed on SUS304 stainless steel that were covered with thin water layer containing various kinds of salt and exposed to atmospheric corrosion environment of 90％ relative humidity and 60℃ were characterized using X-ray photoelectron spectroscopy (XPS). Thickness and Cr content of passive films were affected by a minute amount of salts provided on the surface as a thin water layer. Thickness of the thin water layer on the surface of the steel seemed to be controlled by the equilibrium relative humidity of saturated solution of chlorides supplied on the specimen. Namely, the thickness of the thin water layer containing chloride with low equilibrium relative humidity was larger compared to that containing the chloride with higher equilibrium relative humidity. As a result, the selective dissolution of Fe is stimulated under the thicker water layer to be the more Cr containing passive films. Chlorides enhanced the formation of more Cr enriched passive films, but more concentrated chloride caused localized corrosion. In particular, passive films formed with the thin water layer containing suitable amount of sodium chloride occasionally exhibited high localized corrosion resistance. Sulfates also accelerated the selective dissolution of Fe and increased Cr content in passive films, resulting in stable growth of passive film without localized corrosion.
Publisher
腐食防食学会
Japan Society of Corrosion Engineering
Source Title
材料と環境
Volume (Issue)
62(4)
Page
148-152
Date of Issued
2013-04-15
Language
Japanese
Handle URL
https://hdl.handle.net/11094/82365
PISSN
09170480
eISSN
18819664
NCID
AN10235427
Relation.isIdenticalTo
DOI (Publisher Version)
https://doi.org/10.3323/jcorr.62.148
Access Rights
open access
oaire:version
Version of Record
Category
学術雑誌論文 Journal Article