不動態化とは金属の表面に酸化した被膜ができ、内部を酸による腐食や、酸化などから保護する状態のこと。
ステンレスに含まれるクロムが酸素と結びついて表層につくる薄く緻密な膜が不動態膜です。
このクロムリッチな膜が腐食から素地を守ります。
逆にクロムと酸素の結びつきが塩素などで壊されたり、クロムの欠乏部があったりするとサビが発生しやすくなります。
不動態化処理は下記の方法があります。
硝酸などの強酸化剤で処理する方法
酸素のある雰囲気中で加熱する方法
酸液中で陽極分極する方法
Rating
57
Native
Translation / English
- Posted at 14 Dec 2020 at 18:31
Passivation is a state in which an oxidized film is formed on the surface of a metal to protect its innards from corrosion caused by acid and oxidation.
A passivation film is a thin and dense film formed on the surface via combining oxygen with chromium contained in stainless steel.
This chrome-rich film protects the substrate from corrosion.
If the bond between the chromium and oxygen is broken by chlorine, or if there is a deficiency of chromium, then rust is likely to occur.
The following methods for passivation processing exist.
Treating via a strong oxidizing agent such as nitric acid
Heating in an oxygenated atmosphere
Anodic polarization in acid solution
A passivation film is a thin and dense film formed on the surface via combining oxygen with chromium contained in stainless steel.
This chrome-rich film protects the substrate from corrosion.
If the bond between the chromium and oxygen is broken by chlorine, or if there is a deficiency of chromium, then rust is likely to occur.
The following methods for passivation processing exist.
Treating via a strong oxidizing agent such as nitric acid
Heating in an oxygenated atmosphere
Anodic polarization in acid solution
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Rating
52
Translation / English
- Posted at 14 Dec 2020 at 18:51
The passivation means the oxide coating formed on the surface of metal protects from erosion or oxidation occurring by acid internally. A thin fine film which is formed over the surface created by oxygen with chrome containing stainless is a passive state film.
This film is rich in chrome and protects materials from erosion.
Contrarily, if the connection of chrome and oxygen is damaged by chlorine and others or a deficiency of chrome exists, the rust might be formed.
The process of passivation will be followed.
The method of processing by strongly oxidizing agents such as nitric acid.
The method of heating in an atmosphere of being in oxygen.
The method of anodic polarization in acid solution.
This film is rich in chrome and protects materials from erosion.
Contrarily, if the connection of chrome and oxygen is damaged by chlorine and others or a deficiency of chrome exists, the rust might be formed.
The process of passivation will be followed.
The method of processing by strongly oxidizing agents such as nitric acid.
The method of heating in an atmosphere of being in oxygen.
The method of anodic polarization in acid solution.
Rating
52
Translation / English
- Posted at 14 Dec 2020 at 18:22
Passive treatment is a condition in which an oxidized film is formed on the surface of a metal to protect the interior from acid corrosion and oxidation.
The chromium in stainless steel combines with oxygen to form a thin, dense passive film on the surface layer.
This chromium-rich film protects the substrate from corrosion.
However, if the chromium-oxygen bond is damaged by chlorine or other substances, or if there is a lack of chromium, rust can easily occur.
The following passivation methods are available.
Treatment with a strong oxidizing agent such as nitric acid
Heating in an atmosphere with oxygen
Anodic polarization in an acid solution
The chromium in stainless steel combines with oxygen to form a thin, dense passive film on the surface layer.
This chromium-rich film protects the substrate from corrosion.
However, if the chromium-oxygen bond is damaged by chlorine or other substances, or if there is a lack of chromium, rust can easily occur.
The following passivation methods are available.
Treatment with a strong oxidizing agent such as nitric acid
Heating in an atmosphere with oxygen
Anodic polarization in an acid solution
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