Principle of passivation of stainless steel pickling

Because appearance is enclothing,the corrosion resistance of stainless steel basically can be paper-thin (make an appointment with the passivation film with close 1nm) , this film is the essential protective screen that stainless steel defends. Stainless steel passivation is had
Dynamic feature, ought not to regard corrode complete break down, form dispersive barrier layer however, make positive pole reacts rate falls greatly. Be in commonly have reducer (like chloric ion) the tendency below the circumstance
At attaint film, and in oxidizer (like air) can hold to when existence or amend film.
Stainless steel workpiece puts the meeting in park air to make oxidation film, but the protection of this kind of film is no good perfect. Want to undertake complete cleanness first commonly, include alkaline wash with pickling, reoccupy oxidant is blunt
Change, ability ensures the integrality of passivation film and stability. One of intents of pickling are to be passivation to handle creation advantage, ensure make exceedingly good passivation film. Because make through pickling
Stainless steel appearance has 10μm equably thick an appearance is corroded, the chemical active of acerbity fluid makes the deliquescent rate of defect place higher than place of the other on appearance, consequently pickling can make be expressed entirely
The face tends even balance, a few form cankerous danger simply to be eradicated originally. But more important is, through pickling passivation, make the oxide of iron and iron compares chromium and chromic oxidation
Content is preferential and deliquescent, take out deficient chromic layer, form chromium to be in rich collect of stainless steel appearance, the potential of film of this kind of rich chromic passivation can be amounted to + 1.0V(SCE) , get close to the potential of precious metal, rose to fight
Cankerous stability. Different passivation processing also can affect velar composition and construction, affect thereby do not become rusty quality, if pass electrochemistry modified processing, can make passivation film is had multilayer and tectonic
, crO3 or Cr2O3 are formed in barrier layer, or the oxidation film that makes vitreous appearance, make stainless steel can be behaved the biggest be able to bear or endure corrode sex.
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