304 stainless steel surface passivation treatment is mainly to improve the corrosion resistance of stainless steel and extend its service life. The usual passivation treatment methods are pickling passivation or electrochemical passivation.
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The pickling passivation process is as follows:
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1. Decontamination: Remove the dirt and oxide on the surface of 304 stainless steel.
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2. Pickling: The use of dilute nitric acid or other acidic solutions for pickling to remove the oxide layer and surface roughness.
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3. Passivation: The surface of 304 stainless steel is in a certain acidic environment, and reacts with a solution containing fluorine compounds to form a thin, dense, uniform passivation film. This passivation film protects the surface of the stainless steel, improving its corrosion resistance and durability.
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4. Washing: After passivation treatment, be sure to carry out sufficient water washing to remove the passivation treatment agent residue attached to the surface.
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The electrochemical passivation process is as follows:
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1. Decontamination: Remove the dirt and oxide on the surface of 304 stainless steel.
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2. Anodizing: Make an anode of 304 stainless steel and anodize it in an acidic electrolyte.
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3. Electrolysis: After the end of anodic oxidation, electrolytic solution is used for electrolysis to generate a dense and uniform passivation film.
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4. Rinse: After passivation is completed, full water is washed to remove the electrochemical treatment agent attached to the surface.
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Hello, 304 stainless steel surface passivation process generally includes the following steps:
1. Cleaning: Clean the surface of 304 stainless steel to be treated and remove the oil, dust and other impurities on the surface.
2. Pickling: The cleaned 304 stainless steel surface is soaked in an acidic solution, usually using an acidic solution mixed with nitric acid and hydrofluoric acid to remove the surface oxide and rust.
3. Rinse: Rinse the surface of 304 stainless steel with clean water after pickling to remove the residual acidic solution.
4. Passivation: The rinsed 304 stainless steel surface is soaked in a solution containing chromic acid and fluoride for passivation. Passivation treatment can form a dense chromium oxide film on the surface to improve the corrosion resistance of stainless steel.
5. Rinse again: Rinse the surface of 304 stainless steel after passivation with clean water to remove the residual passivation liquid.
6. Drying: dry the rinsed 304 stainless steel surface or dry with a hair dryer to complete the passivation treatment.
It should be noted that the passivation process of different manufacturers and users may be different, and the specific process parameters and treatment methods should be adjusted according to the actual situation.
Stainless steel passivation process:
1. Pre-treatment, oil removal, rust removal, oxidation, etc., no matter what kind of surface engineering process, to obtain good results, clean surface is the primary condition, the purpose of pre-treatment foot to ensure the integrity and density of passivation film, with good corrosion resistance;
2. Pickling activation, the purpose is to remove the surface is incomplete, not strong oxide film, can make the protective film formed during passivation more complete and consistent, corrosion resistance is stronger.
3. Passivation treatment, using passivation solution for treatment,
4. Neutralization treatment, the purpose is to neutralize the residual acid passivation liquid on the surface of the workpiece with lye, to avoid acid corrosion caused by acid residue to destroy the passivation film.
Stainless steel hanging → chemical degreasing (conventional alkaline chemical degreasing or surfactant degreasing) → hot water washing → running water washing → First step pickling → running water washing → Second step pickling → running water washing → Transfer to the next process (such as: chemical coloring → recycling → running water washing → hardening treatment → running water washing → Closed treatment → running water washing → drying → finished product [4])