How exactly does passivation happen?

Passivation, in fact, is the metal that reacts with the liquid first, and then forms a dense oxide film to prevent the reaction from proceeding!

Passivation: After iron and copper meet concentrated sulfuric acid, iron and aluminum meet concentrated nitric acid, an oxide film is formed on the surface, so that the metal inside is no longer corroded.

Passivation refers to the passage of metals with strong oxidizing agents.

Or electrochemical oxidation treatment, so that the surface into an inactive state, that is, passivation process, is to transform the metal surface into a state that is not easy to be oxidized, and delay the corrosion rate of the metal. In addition, an active metal or alloy, in which the chemical activity is greatly reduced, and becomes a state, is also called passivation.

Basic meaning. Passivation, if the corrosion products generated by the metal due to the action of the medium have a dense structure, forming a thin film (often invisible), which is tightly covered on the surface of the metal, it changes the surface state of the metal, so that the electrode potential of the metal jumps greatly in the positive direction, and becomes a corrosion-resistant blunt state. For example, when Fe Fe2+, the standard potential is , and it jumps to + after passivation, and shows the best corrosion resistance, this film is called passivation film.

Passivation of metals can also be spontaneous (e.g., the formation of a layer of insoluble compounds, known as oxide films, on the surface of metals). In industry, the metal is passivated with passivating agent (mainly oxidant) to form a protective film.

Common example: cold concentrated sulfuric acid.

Cold concentrated nitric acid. Passivation can occur with iron and aluminum.

Corrosion definition. Corrosion is an electrochemical process in which a small amount of ionized ions are present on the surface of an untreated metal that move from the high-potential region (cathode) to the low-potential region (anode), thus generating an electric current. Under the action of this current, it will accelerate the destructive attack on the metal and cause corrosion in the parts where the metal potential is weak, which is commonly known as rust.

Passivation principle. The mechanism of passivation can be explained by the thin film theory, that is, the passivation is due to the interaction between the metal and the oxidizing substance, and a very thin, dense, well-covering passivation film is generated on the metal surface during the action, and it is firmly adsorbed on the metal surface. This film exists in separate phases, usually compounds of oxidized metals.

It plays the role of completely separating the metal from the corrosive medium, preventing the metal from coming into contact with the corrosive medium, so that the metal basically stops dissolving and forms a blunt state to achieve the effect of anti-corrosion.

with anti-rust oil. The main difference between passivation and antirust oil is that the product is different; Anti-rust oil is the use of oil film to seal the pores on the metal surface to isolate contact with oxygen and effectively prevent rust, in fact, there is no reaction. The oil film is relatively easy to be removed and destroyed with the progress of production; Passivation is the use of oxidizing substances in the passivation solution to produce redox reactions with metals, so as to promote the formation of a layer of metal oxides on the surface of the metal to achieve the purpose of effectively protecting the metal.

This process is a chemical reaction.

The resulting passivation film is dense, intact and not easy to be destroyed.

When pure iron and aluminum encounter concentrated sulfuric acid or concentrated nitric acid, the atoms on the surface react with the acid to produce a dense oxide film, which prevents the internal substances from continuing to react with the concentrated acid and plays a protective role. This is called passivation.

Some metals, such as iron and aluminum, will be oxidized in concentrated sulfuric acid or concentrated nitric acid to form a dense oxide film, preventing these metals from continuing to react with concentrated acid, this phenomenon is called passivation.

When pure iron and aluminum encounter concentrated sulfuric acid or concentrated nitric acid, the atoms on the surface react with the acid Qi Wangyu to produce a dense oxide film, which prevents the internal substances from continuing to react with the concentrated acid and plays a protective role.

When pure iron and aluminum encounter concentrated sulfuric acid or concentrated nitric acid, the atoms on the surface react with the acid to produce a dense oxide film, which prevents the internal substances from continuing to react with the concentrated acid and plays a protective role. This is called passivation of high rock.

When pure iron and aluminum encounter concentrated sulfuric acid or concentrated nitric acid, the atoms on the surface react with the acid to produce a dense oxide film, which prevents the internal substances from continuing to react with the concentrated acid and plays a protective role. This is called passivation.

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Iron, aluminum and other active metals can be quickly dissolved in dilute nitric acid or dilute sulfuric acid, but the dissolution phenomenon in concentrated nitric acid or concentrated sulfuric acid is almost completely stopped, carbon steel is usually easy to rust, if an appropriate amount of nickel and chromium is added to the steel, it will become stainless steel.

The essence of metal passivation is that the metal is oxidized by concentrated sulfuric acid, concentrated nitric acid, etc., and a dense oxide film is formed on the surface, and this oxidation mask film is insoluble in concentrated sulfuric acid and concentrated nitric acid, because the hydrogen ions ionized by concentrated sulfuric acid and concentrated nitric acid are relatively small. Oxidants such as hypochlorous acid and potassium permanganate can also passivate metals or alloys.

The explanation of the word passivation is: passivation dùnhuà. 1.

诎氲 Ji Ba Concubine Xian Shao Wandering QiOsprey Reclamation Barge, Pepper, Pepper, Hook, Knowledge, Blow, Tomb Otter 3Furaearrhoea, plutonium, sodium and sodium.

The explanation of the word passivation is: passivation dùnhuà. 1.

诎氲 Ji Ba Concubine Xian Shao Wandering QiOsprey Reclamation Barge, Pepper, Pepper, Hook, Knowledge, Blow, Tomb Otter 3The structure of the furnishing dysentery is as follows:

Blunt (left-right structure) (left-right structure). Pinyin is: dùnhuà.

What is the specific explanation of passivation, we will introduce it to you through the following aspects:

1. Online explanation [click here to view the details of the plan].

Passivation is a method of transforming the surface of a metal into a state that is not easily oxidized, while delaying the corrosion rate of the metal. In addition, an active metal or alloy, in which the chemical activity is greatly reduced, becomes the phenomenon of the first state, also called passivation.

Idioms about passivation.

The past generations have been dull, the world has been dull, the mouth is blunt, the cheeks are dull, the armor is blunt, the success or failure is blunt, the learning is dull, the words are dull, the eyebrows are dull, the eyes are dull, the eyes are dull, and the children are dull.

Words about passivation.

Stubborn grinding dull decay Ge blunt armor over the ages, dull strategy, dull mouth, blunt cheeks, success or failure, dull stubbornness, stubbornness, dull

Sentence formation about passivation.

1. The results show that the passivation film is a double-layer structure composed of a surface layer and a transition layer.

2. The post-treatment technology for chemical cleaning was introduced, and the rinsing and passivation processes were discussed.

3. I plead not to mistake freedom for chaos, and to regain the faith that connects the visible and the unseen, but does not dull the mind. Adam Zagajewski.

4. The alkali treatment silicon washing and passivation process has been adopted on the subcritical parameter boiler of the steep river power plant, and good economic results have been obtained.

5. The method of determining tin in metal passivator by flame atomic absorption spectrometry was studied.

Passivation reactions. It refers to the phenomenon that the chemical stability of a metal or alloy is significantly enhanced due to some factors, which is called passivation. The phenomenon of metal passivation caused by certain passivators (chemicals) is called chemical passivation.

Oxidants such as concentrated HNO3, concentrated H2SO4, HCO3, K2Cr2O7, KMno4 and other oxidants can passivate metals.

Iron and aluminum can be quickly dissolved in dilute Hno3 or dilute H2SO4, but the dissolution phenomenon in concentrated Hno3 or concentrated H2SO4 is almost completely stopped, carbon steel is usually easy to rust, if an appropriate amount of Ni and Cr is added to the steel, it will become stainless steel.